ID - Bacterial Infections / ABXs Flashcards

Question

ABX Dosing Optimization: which ABXs are concentration dependent, AUC dependent, and time dependent? -Goals with each category -Dosing strategies with each category

Answer 1

Concentration Dependent (Cmax: MIC): aminoglycosides, quinolones, daptomycin -Goal: high peak to increase bactericial activity and low troughs to decrease toxicity -Dosing strategies: larger dose with longer intervals (dosed less frequently) AUC: MIC - vancomycin, macrolides, tetracyclines, polymxins -Goal: exposure over time -Dosing strategies: variable Time > MIC (Time-dependent): beta-lactams (PCNs, cephalosporins, carbapenems) -Goal: maintain drug level > MIC for most of dosing interval -Dosing strategies: shorter dosing interval, extended or CIV -> just care about how long the drug levels are > MIC

Answer 2

-Beta-lactams (PCNs, cephalosporins, carbapenems) and monobactams (aztreonam): bind to PCN-binding proteins (PBPs) which prevent peptidoglycan synthesis -Vancomycin: binds to D-alanine-D-alanine cell wall precursor to peptidoglycans -Dalbavancin, telavancin, ortivancin

Answer 3

clindamycin, linezolid, tedizolid -30S Ribosome: aminoglycosides, tetracyclines -50S Ribosome: macrolides

Answer 4

polymyxins, daptomycin, televancin, ortivancin -Daptomycin: binds to cell wall components causing rapid depolarization, inhibiting intraceullar replication processes including protein synthesis

Answer 5

quinolones, metronidazole, tinidazole, rifampin -Quinolones: toposiomerase IV and DNA gyrase (toposomerase II), promoting breakage of ds DNA

Answer 6

sulfonamides, trimethoprim, dapsone -Sulfamethoxazone (SMX): inhibits dihydrofolic acid formation, inhibiting folic acid synthesis -Trimethoprim (TMP): inhbitts dihydrofolic acid reduction to tetrahydrofolate, inhibitng folic acid pathway

Answer 7

Natural PCNs (penicillin G/V): streptococci, enterococci, and GP anaerobes in mouth flora (peptostreptococcus) Antistaphylococcal (nafcillin, oxacillin, dicloxacillin): MSSA and streptococci only Aminopenicillins (amoxicillin, ampicillin): natural PCN coverage + GN coverage (HNPEK) Aminopenicillin + Beta-lactamase inhibitor (amoxicillin/clavulanate, ampicillin/sulbactam): MSSA, more resistant strains of HNPEK, GN anaerobes (B. fragilis) Extended spectrum + Beta-lactamse inhibitor (piperacillin/tazobactam): aminopencillin/beta-lacatamase coverage + CAPEs and Pseudomonas coverage Class Trends: -Do NOT cover MRSA, atypical pathogens (NO cell wall) -ALL cover enterococcus except anti-staph PCNs *HNPEK: Haemophilus, Neisseria, Proteus, E.coli, Klebsiella *CAPES: Citrobacter, Actinetobacter, Providencia, Enterobacter, Serratia

Answer 8

-PO: PCN V Potassium (Pen VK) -IV: PCN G Aqueous -IM: PCN G Benzathine (Bicillin L-A) --> NEVER give IV (cardio-respiratory arrest and death)

Answer 9

-PO: dicloxacillin -IV: nafacillin. oxacillin

Answer 10

-PO: amoxicillin (Moxatag) -IV: ampicillin (does come in PO, but RARELY used since poor bioavailability)

Answer 11

-PO: amoxicillin/clavulanate (Augmentin) -IV: ampicillin/sulbactam (Unasyn)

Answer 12

-IV: piperacillin/tazobactam (Zosyn) - prolonged or extended infusions

Answer 13

PCN VK: strep throat, mild skin infections Amoxicillin: acute otitis media, infective endocarditis prophylaxis, H. pylori Augmentin (amoxicillin/clavulanate): acute otitis media PCN G Benzathine (Bicillin L-A): syphilus --> NEVER use IV (cardio-respiratory arrest and death) Zosyn (piperacilllin/tazobactam): Pseudomonas --> extended-infusion common

Answer 14

Pediatrics: -Amoxicillin component: 90mg/kg/day (acute otitis media: divide into BID) -Clavulanate: use LOWEST dose (diarrhea) Infective endocarditis prophylaxis prior to dental procedure: 2 grams PO x1 30-60 minutes before procedure Benzathine G Benzathine: 2.4 million units IM x1 for early intervention or Qweek for 3 weeks (NEVER IV: lipid emulsion that can cause death) NO renal dose adjustments: anti-staphy PCNs (nafacillin, oxacillin, dicloxacillin) do NOT use in CrCl <30mL/min: Augmentin XR or 875mg strength

Answer 15

1. -Beta-lactam allergy (except for syphilus during pregnancy or in pts with poor compliance/follow up --> densenitize and use treat w/ PCN G Benzathine) -Try to avoid in hx of seizures (especially if decreased renal function) 2. seizures (with accumulation), GI upset, diarrhea, rash (including SJS/TENs), hemolytic anemia (positive Coombs test), renal failure, increased LFTs 3. Nafcillin - if extravasation, cold packs and hyaluronidase injections

Answer 16

1. Ampicillin including ampicillin/sulbactam 2. Hx of cholestatic jaundice or hepatic dysfunction asosciated with previous usage 3. -PROBENACID: increases level of beta-lactams -PCNs can increase methotrexate concentrations -Warfarin: PCNs enhance effects except nafcillin and dicloxacillin inhib

Answer 17

1GC (cefazolin, cephalexin): staphylococci, streptococci, PEK, mouth anaerobes (Peptostreptococcus) --> very similar to aminopenicillins 2GC (cefuroxime, cefotetan, cefoxitin): better GN activity (HNPEK) -Cefoxitin, cefotetan: have anaerobic coverage (B. fragilis) 3GC: -Group 1 (ceftriaxone, cefdinir): less staphylococci coverage, but better streptococci coverage -Group 2 (ceftazidime, ceftazidime/avibactam): Pseudomonas 4GC (cefepime): broad; GP, HNPEK, CAPEs, Pseudomonas 5GC (ceftaroline): similar to ceftriaxone + MRSA coverage Cefiderocol: PEK, Enterobacter, Pseudomonas Class trends: -NOT active against Enterococcus spp. or atypical organisms (NO cell wall) -GN coverage increases typically with each generation

Answer 18

PO: -Cephalexin (Keflex) -Cefdinir (Omnicef - now D/C brand) -Cefixime (3GC) - chewable tablets IV: -Cefazolin (Ancef) -Ceftazidime (Tazicef), ceftazidime/avibactam (Avycaz) -Cefepime (Maxipime) -Ceftaroline (Teflaro) IV, IM: ceftriaxone (Rocephin) PO, IV, and IM: cefuroxime (Ceftin)

Answer 19

1GC: -Outpatient: cephalexin --> strep throat, MSSA skin infections -Inpatient: cefazolin --> surgical prophylaxis 2GC: -Outpatient: cefuroxime --> acute otitis media, CAP, sinus infections -Inpatient: cefotexan, cefoxitin --> surgical prophylaxis (GI procedures due to anaerobe coverage) 3GC: -Outpatient: cefdinir --> CAP, sinus infections -Inpatient: ceftraixone, cefotaxime --> CAP, meningitis, SBP, pylonephritis Pseudomonas: ceftazidime, cefepime MRSA: ceftaroline

Answer 20

1. Penicillin allergy due to potential cross-reactivity (exceptions: mild PCN allergy, acute otitis media in pediatric pts since NOT many other options) 2. -PCN symptoms: seizures (with accumulation, especially in renal dysfunction), GI upset, diarrhea, rash (including SJS/TENs), hemolytic anemia (positive Coombs test), increased LFTs, -Others: acute interstitial nephritis, myleosuppression (prolonged use), drug fever 3. Cefotetan 4. Renal function, s/sx of anaphylaxis, CBC, LFTs

Answer 21

1. Ceftriaxone 2. Ceftazidime/avibactam 3. Neonates 0-28 days old -Hyperbilirubinemic neonates (biliary sludging, neonates) -Concurrent use w/ Ca-containing IV products in neonates (contributes to sludge as well) 4. Oral cephalosporins can have less bioavailability w/ decreased stomach acid -Avoid H2RAs and PPIs -Seperate from antacids

Answer 22

Drugs: meropenem (Merrem), meropenem/vaborbactam (Vabomere), impinem/cilastatin (Primaxin IV), imipenem/cilastatin/relebactam (Recarbrio), ertapenem (Invanz) ROA: IV -Ertapenem: IV and IM --> MUST be diluted in NS Coverage: reserved for MDR GNRs (including ESBL) -NO coverage of: atypical pathogens (NO cell wall), MRSA, VRE, C. diff, Stenotrophomonas -ErtAPenem: NO activity against Enterococcus, Actineobacter, and Psuedomonas ("EAP") Indications: -Polymicrobial infections (ex. severe diabetic foot infections) -Empiric therapy w/ resistant organisms suspected -ESBL-positive infections -Resistant pseudomonas or Actineobacter infections (except ertapenem)

Answer 23

AVEs: diarrhea, rash/severe skin rxns (DRESS), bone marrow suppression w/ prolonged use, increased LFTs Warnings/CIs: -Avoid with PCN allergy, especially in serious allergies -CNS AVEs: confusion, SEIZURES (higher risk w/ imipenem/cilastatin, large doses, or impaired renal fxn) -Caution in pts taking medications that lower seizure threshold (quinolones, clozapine, bupropion, tramadol) Monitoring: renal function, allergic rxns, CBC, LFTs DDIs: can decrease valproic acid levels, increasing seizure potential

Answer 24

Drug: aztreonam (Azactam) ROA: IV (Cayston for inhaled in cystic fibrosis) Coverage: GN organisms including Pseudomonas and CAPES -NO gram positive coverage -NO anaerobe coverage Typical indication: used when pencillin allergy present (cross-sensitivity VERY UNLIKELY with single ring structure)

Answer 25

Drugs: gentamicin, tobramycin, amikacin, streptomycin, plazomicin ROA: IV or IM (Tobramycin also has inhalation for cystic fibrois - Tobi, Bethkis, Kitabis Pak) Coverage: GP and GN broad activity including Pseudomonas (mostly Tobramycin) Typical Indications: USUALLY NOT MONOTHERAPY -Genatamicin and Streptomycin: synergy in combo w/ beta-lactam or vancomycin when treating GP infections (staphylococci, enterococci) -Empiric therapy for GN with other ABXs

Answer 26

Dosing Strategies: -Extended interval dosing to take advantage of concentration-dependent kinetics -Larger doses less frequenctly to also give kidneys time to recover between doses) -LOWER dosing for GP infections Traditional Dosing: -Usually 1.25-5mg/kg IV: use Q8H if CrCl >/= 60mL/min -Trough: draw before or 30 minutes before 4th dose (goal: <2 mcg/mL) -Peak: draw 30 minutes after end of infusion for 4th dose (goal: 5-10 mcg/mL) -Higher TROUGH associated with MORE TOXICITY Extended Interval Dosing: -4-7 mg/kg IV Q24H (usually 7mg/kg) -Draw random level and use nomogram to determine frequency -Harford nanogram: determine time random level done and concentration to then see where it falls for time interval (if lands exactly on line go up to next dosing interval) Selecting a weight when dosing: -Underweight < IBW: use total body weight -Normal weight: IBW or TBW (depends on institutional protocol) -Obese: adjusted BW

Answer 27

Warnings: -Caution in impaired renal function or older adults -Caution with additive neurotoxic drugs: amphotericin B, cisplatin, polymyxins, cyclosporine, tacrolimus, loop diuretics, NSAIDs, radiocontrast dye, vancomycin BBW: nephrotoxocity, ototoxicity (ataxia, vertigo, hearing loss), neuromuscular blockade and respiratory paralysis -AVOID with other nephrotoxic drugs -Fetal harm in pregnancy Monitoring: drug levels, renal function, urine output, hearing tests

Answer 28

Drugs: ciprofloxacin (Cipro), levofloxacin (Levaquin), Moxifloxacin (Avelox), delafloxacin, gatifloxacin, ofloxacin ROA: PO or IV (Ocuflox - ofloxacin eye drops, Ciloxan - ciprofloxacin eye drops, Cetraxal - ciprofloxacin ear drops) -IV to PO ratio: 1:1 (great bioavailability) Coverage: GP and GN broad spectrum -"Respiratory fluroquinolones": levofloxacin, moxifloxacin, and gemifloxacin (enhanced coverage of S. pneumoniae and atypical pathogens) -Pseudomonas: ciprofloxacin, levofloxacin (enhanced GN activity) -Moxifloxacin: more GP activity and anaerobes--> cannot be used in UTIs (does NOT concentrate in urine) -Delafloxacin: MRSA activity (others should be avoided due to MRSA resistance likelihood) Indications: last-line infections if no alternatives --Last line for acute bacterial sinusitis, acute exacerbation of chronic bronchitis, and uncomplicated UTI (BBW) -Pseudomonas infections, UTI, intra-abdominal infections, traveler's diarrhea NO renal adjustment: moxifloxacin (think about how it does NOT concentration in urine)

Answer 29

AVEs: N/D, HA, dizziness, serious skin rxns (SJS/TENs) Warnings: -QT prolongation (highest risk: moxifloxacin > levofloxacin > ciprofloxacin): avoid with known QT prolongation or those with additive risk (hypokalema, QT prolonging drugs) -Hypoglycemia and hyperglycemia -Psychiatric disturbances (agitation, disorientation, lack of attention, nervousness, memory impairment, delirium) -Avoid in children and pregnancy/breastfeeding due to musculoskeletal toxicity risk (exception: anthrax exposure) -Aortic aneurysm and dissection (increased risk w/ longer durations or hx of peripheral vascular disease, atherosclerosis, or prior aneurysms) -Photosensitivity, hepatotoxicity, crystalluria (stay hydrated)

Answer 30

BBW: -Tendon inflammation and/or ruptuure often in Achilles tendon within start up to several months after TX (increased risk w/ systemic steroids, organ transplant recipients, >60 yo) --> D/C immediately if symptoms occur -Peripheral neuropathy: can last months to years after D/C and may become permenanent --> D/C immediately if symptoms occur -CNS effects (seizures, tremor, restlessness, confusion, suicidal thoughts, etc.): caution in CNS disorders or drugs that cause seizures/lower threshold -Avoid in myasthenia gravis (may exacerbate weakness) CI: ciprofloxacin with concurrent administration of tizanidine

Answer 31

1. Antacids, polyvalent cations (Mg, Al, Ca, Phos, Iron, Zinc), multivitamins, sucralfate, bile acid resins: chelate and inhibit quinolone absorption 2.Phosphate binders (lanthanum, sevelamer): decrease concentration of PO quinolones (separate) 3. Quinolones can increase effects of: warfarin, sulfonylureas, insulin, and other hypoglycemic drugs 4. Caution w/ QT prolonging drugs or drugs that w/ CVD/decrease K/Mg: azole antifungals, antipsychotics, methadone, macrolides 5. Ciprofloxacin: strong CYP1A2 inhibitor: can increase levels of caffeine, theophylline, tiazanidine

Answer 32

Drugs: azithromycin (Zithromax, Zpak), clarithromycin (Biaxin), erythromycin (E.E.S = erthromycin stearate, Erthyrocin) ROA: -Azithromycin: PO or IV -Clarithromycin: PO -Erythromycin: PO, IV, topical, opthalamic Coverage: -Great atypical coverage (Legionella, Chlamydia, Mycoplasma, Mycobacterium avium) -Respiratory: H. influenzae, S. pneumonie, Moraxella (having increasing resistant rates) Typical Indications: -Community acquired upper and lower respiratory tract infections; strep throat -Azithromycin: COPD exacerbations, chlamydia, gonorrhea, MAC prophylaxis -Clarithromycin: H. pylori -Erythromycin: increase gastric motility

Answer 33

Z-pak: Two 250mg (500mg) on day then 250mg QD x4 days Tripak: 1 azithromycin 500mg tablet QD x3 days

Answer 34

AVEs: GI UPSET (diarrhea, abdominal pain, cramping), taste perversion, ototoxicity (rare, reversible), severe skin infections (rare) Warnings: -QT prolongation: highest risk with erythromycin > azithromycin > azithromycin --> avoid in pts with known QT prolongation, elecrolyte abnormalties, and QT prolonging drugs -Hepatotoxicity -Exacerbation of myasthenias gravis -Clarithromycin: caution in CAD (increased mortality been documented 1 year or after end of 2 week TX course) Cis: -Hx of cholestatic jaundice/hepatic dysfunction w/ prior use -Clarithromycin and erythromycin: usage w/ lovastatin or simvastatin -Clarithromycin: concurrent use with colchicine w/ renal or hepatic impairment DDIs: -Erthyromycin and Clarithromycin: major CYP3A4 inhibitors and substrates --> CYP3A4 subsrates some are CI (lovastatin and simvastatin) and some monitor (warfarin, apixiban/rivaroxaban, dabigatran, theophylline, colchicine) -Azithromycin: MINOR CYP3A4 subsrate and weak inhibitor -ALL macrolides: caution with QT prolonging drugs

Answer 35

Drugs: doxycycline (Vibramycin, Doryx), minocycline (Minocin, Solodyn), eravacycline, omadacycline, sarecycline, tetracycline ROA: PO or IV IV to PO ratio: 1:1 (doxycycline, minocycline) NO renal adjustment: doxcycline, minocycline

Answer 36

Coverage: GP and GN coverage -GP: Staphylococci (including CA-MRSA), Streptococci, Enterococci (including VRE), Propionibacterium spp) -GN: respiratory flora (H. influenaze, Moraxella, atypicals) -Unique pathogens: RIckettsiae, Bacillus anthracis, Treponema pallidum, H. pylori (tetracycline) -Doxycycline (often DOC): even broader with tickborne/rickettsial disease, STIs (chlamydia), and respiratory tract infecionts Typical Indications: -CA-MRSA skin infections, acne -Doxycycline: tickborne infections, CAP, COPD exacerbations, sinusitis, VRE UTI, chlamydia, gonorrhea -Tetracycline: H. pylori treatment

Answer 37

AVEs: N/V/D, rash -Doxycyline: take upright for at least 30 minutes (esophageal irritation) Warnings: -Children < 8 yo, pregnancy, breastfeeding: try to avoid (suppressed bone and skeletal development, premanent discolors teeth) -Photosensitivity, tissue hyperpigmentation, severe skin infections (SJS/TEN/DRESS), exfolative dermatitis -GI inflammation/ulceration -Minocycline: drug-induced lupus erythematosus (DILE) Monitoring: LFTs, renal fxn, CBC DDIs: antacids, polyvalent cations, sucralfate, bismuth subsalicylate, and bile acid resins can chelate and inhibit absorption of tetracyclines (ideally avoid, but if not seperate --> seperate dairy products 1 hour before or 2 hours after)

Answer 38

Brand: Bactrim, Bactrim DS ROA: PO or injection Coverage: -GP: Staphylococi (including MRSA), S. pneumoniae --> group A streptococcus activity UNRELIABLE -GN: H. influenzae, E. coli, Protekus, Klebsiella, Enterobacter, SHIGELLA, SALMONELLA, STENOTROPHOMONAS -Opportunistic Inections: Nocardia, Pneumocystitis, Toxoplasmosis -Does NOT cover: Pseudomonas, Enterococci, Atypicals, Anaerobes Typical Indications: -Severe infections -Uncomplicated UTI -Pneumocystis Pneumonia (PCP) prophylaxis or treatment

Answer 39

SS: 400mg SMX / 80mg TMP DS: 800 mg SMX / 160mg TMP **ALL products formulated as SMX:TMP 5:1 ratio Dosing: based on TMP -Uncomplicated UTI: 1 DS tablet PO BID x3D -PCP prophylaxis: QD dosing

Answer 40

AVEs: PHOTOSENSITIVITY, HYPERKALEMIA, CRYSTALLURIA (take with 8oz water), N/V/D, anorexia, skin RASH (fairly common along with hives), decreased folate, false elevations in SCr (due to inhibition of creatinine tubular secretion), renal failure Warnings: -Blood dyscrasias (agranulocytosis, aplastic anemia) -Skin rxns (SJS/TEN), thrombotic thrombocytopenia purpura (TTP) -Hemolytic anemia (can be immune-mediated w/ + Coombs test or G6PD deficiency) -Hypoglycemia, thrombocytopenia -Pregnancy: congenital defects from folic acid blockage (use if benefit outweights risk) CIs: SULFA allergy, anemia from folate deficiency, renal/hepatic disease, infants <2 months Monitoring: renal fxn, electrolytes, CBC, folate DDIs: -CYP2C9 inhibitor: can increase INR with warfarin -Hyperkalemia risk with renal dysfunction or in combo with ACEIs, ARBs, aliskiren, aldosterone receptor antagonists, K-sparing diuretics, cyclosporine, tacrolimus, NSAIDs, drospirenone-containing oral contraceptives, or canagliflozin -Bactrim can enhance toxic effects of methotrexate -Bactrim effects can be diminished with leucovorin or levoleucovorin

Answer 41

Brand: Vancocin ROA: PO or IV -PO has poor bioavailability (LARGE compound that cannot absorb across GI) Coverage: GP ONLY -Staphylococcus (including MRSA), streptococci, enterococci (NOT VRE) -C. difficle (PO ROUTE ONLY) Typical Indications: -C. difficle -Serious MRSA infections: bacteremia, sepsis, endocarditis, pneumonia, osteomyelitis, meningitis -Other infections: UTIs, skin infections Consider alternative when: MRSA MIC >/=2 mcg/mL

Answer 42

Systemic Infection: 15-20mg/kg IV Q8-12H -Dose based on TOTAL body weight -CrCl 20-49mL/min: Q24H -AMC/MIC ratio of 400-600 or steady state trough of 15-20mcg/mL (drawn 30 minutes before 4th or 5th dose) for serious infections -Other infections (UTI, skin): goal trough of 10-15 mcg/mL C. difficle: 125mg PO QD x10D -500mg QID for severe, complicated disease in combo w/ IV metronidazole -No renal dose adjustments Warnings: -Ototoxicity and nephrotoxicity: caution with other meds w/ same toxicities or w/ prolonged high serum concentrations -IV formulation NOT effective for C.diff (does NOT cross GI tract) -Vancomycin infusion rxn: maculopapular rash, hypotension, flushing, chills --> do NOT infuse faster than 1 gram per hour

Answer 43

Drugs: telavancin (Vibativ), ortivancin (Orbactiv, Kimyrsa), dalbavancin (Dalvance) ROA: IV -Oritavancin, dalbavancin: single-dose regimen Typical Indications: similar coverage to vancomycin -Skin and soft-tissue infections (SSTIs) -Televancin: HAP and VAP

Answer 44

Warnings: -Infusion rxn (similar to vancomycin) w/ rapid administration -Ortivancan, dalbavancin: FALSELY elevate PT/INR, but do NOT increase bleeding risk -Televancin: QT prolongation (avoid other QT-prolonging medications) -Ortivancin: use different ABX if osteomyelitis or suspected -Dalbavancin: increases ALTs >3x ULN CI: -Televancin: concurrent use w/ IV UFH -Ortivancin: do NOT use IV UFH for 120 hours (5 days) after administration due to interference w/ aPTT results (can increase PT/INRT up to 12 hours as well) BBW: -FETAL risk: obtain pregnancy test prior to therapy -NEPHROTOXICITY: increased mortality due to renal impairment compared to vancomycin

Answer 45

Brand: Cubicin ROA: IV -compatible w/ NS and LR (no dextrose) Typical Indications: SSTIs, bloostream infections/endocarditis -do NOT use in pneumonia (does NOT penetrate lungs) AVEs: increased CPK, abdominal pain, chest pain, edema,. HTN, AKI Warnings: -Myopathy and rhabdomyolysis: D/C in pts w/ s/s/sx and CPK >1000units/L or asymptomatic w/ CPK >2000unilts/L --> consider temporarily withholding other drugs that cause muscle damage (ex. statins) during TX -Can falsely elevate PT/INR (NO bleeding risk) -Peipheral neuropathy -DRESS, eosinophilic pneumonia: generally 2-4 weeks after TX Monitoring: CPK weekly (more frequently if on statin or w/ renal impairment), muscle pain/weakness, s/sx of neuropathy, dyspnea

Answer 46

Brand: Zyvox Drug class: oxazolidinone IV to PO ratio: 1:1 -> NO renal dose adjustments Administration: suspension should NOT be shaken Coverage: vancomycin coverage + VRE Typical indications: SSTIs, VRE infections, pneumonia, bloodstream infections -Tedizolid: only for SSTIs

Answer 47

AVEs: decreased PLTs/Hgb/WBCs, HA, N/D, increased LFTs Warnings: -Duration-related myleosupression (thrombocytopenia, anemia, leukopenia) when used > 14 days -Peripheral and optic neuropathy when used >28 days -Serotonin syndrome -Hypoglycemia, hyponatremia, seizures, lactic acidosis, increased BP (caution in uncontrolled HTN or hyperthyroidism) CIs: within 2 weeks of MAOI use Monitoring: weekly CBC, HR, BP, BG in DM, visual function DDIs: linezolid is a reversible MOAI (avoid tyramine-containing foods and serotonergic drugs), exacerbate hypoglycemia episodes (caution in insulin or oral hypoglycemics - sulfonylureas)

Answer 48

Brand: Tygacil MOA: glycycyline that binds to 30S ribsomal subunit to inhibit protein synthesis ROA: IV Administration: solution should be yellow-orange in color Coverage: broad spectrum (MRSA, VRE, gram-negative, anaerobes, and atypicals) -NO activity against 3 P's: Pseudomonas, Proteus, and Providencia Typical indications: complicated SSTIs, intra-abdominal infections, CAP -do NOT use for bloodstream infections AVEs: N/V (can be intractable)/D, HA, dizziness, increased LFTs, rash/severe skin rxns Warnings: anaphylactic rxns (avoid in tetracycline-class allergy), hepatotoxicity, pancreatitis, photosensitivity, bone growth suppression and teeth discoloration (<8 yo) BBW: increased risk of death --> only use when alternative TX not suitable

Answer 49

Drugs: colistimethate (Coly-Mycin M), polymyxin B MOA: cationic detergents that damage bacterial cytoplasmic membrane, causing leakage of intracellular substances and death -Colistimethate is prodrug convertexd to colistin ROA: IV, IM (colistimethate), inhalation (colistimethate) Typical indications: gram-negative (Enterobacter, E. coli, Pseduomonas) -NO activity against Proteus -Due to toxicity risk, primarily for MDR gram-negative pathogens in combo w/ other ABXs Warnings: dose-dependent nephrotoxicity, neurotoxicity (dizziness, HA, tingling, oral paresthesia, vertigo, respiratory paralysis from neuromuscular blockade -Warnings are a BBW in polymyxin B DDIs: additive nephrotoxicity w/ aminoglycosides, ampB, cisplatin, cyclosporine, loop diuretics, NSAIDs, radiocontrast dye, tacrolimus, vancomycin

Answer 50

MOA: reversibly binds to 50S subunit of bacterial ribosome, inhibiting protein synthesis Has gram-positive, gram-negative, anaerobe, and atypical coverage, BUT due to AVEs rarely used (ex. fatal blood dyscrasias - asplastic anemia, pancytopenia, and Gray syndrome - circulatory collpase, cyanosis, and acidosis)

Answer 51

Brand: Cleocin, Cleocin-T, Clindagel, Clindesse, Clindacin Pac, Clindacin-P MOA: lincosamide that binds to 50S subunit of ribosome to prevent protein synthesis ROA: PO, topical (Cleocin-T, Clindagel), vaginal (Clindesse) Administration: -NO renal dose adjustments -Induction test (D-test) should be perfomed on S. aureus (flattened zone between disks = positive = clindamycin resistance) Coverage: most gram-positive bacteria (CA-MRSA, anaerobes) -NO coverage on Enterococcus, gram-negative AVEs: N/V/D, rash, urticaria, increased LFTs (rare) Warnings: severe or fatal skin rxns BBW: colitis (C. difficile)

Answer 52

Brand: Flagyl, Likmz, MetroCream, Metrogel, MetroLotion, Noritate, Nuvessa, Vandazole MOA: induce loss of helical DNA structure and strand breakage, preventing protein synthesis ROA: PO, IV, topical (Metrogel, MetroLotion, Noritate), vaginal (Nuvessa, Vandazole) IV:PO ratio: 1:1 Coverage: anaerobes, protozoal organisms Typical indications: bacterial vaginosis, trichomoniasis, giardiasis, amebiasis, C. difficile, in combo for intra-abdominal infections

Answer 53

AVEs: metallic taste, HA, nausea, furry tongue, dizziness, rash/severe skin rxns Warnings: CNS effects (seizures, peripheral neuropathy), aseptic meningitis, encephalopathy, optic neuropathy CIs: pregnancy (1st trimester), use of alcohol or propylene glycol-containing products during TX or within 3 days of D/C (disulfiram rxn), use of disulfiram in past 2 weeks BBW: possibly carcinogeic (based on animal data) DDIs: alcohol, weak inhibitor of CYP2C9 (can increase INR in pts taking warfarin)

Answer 54

Tinidazole: activity limited to protozoa (glardiasis, amebiasis), trichomoniasis, and bacterial vaginosis Secnidazole: only indicated in bacterial vaginosis and trichomoniasis -Do NOT use in vulvovaginal candidiasis

Answer 55

Brand: Xenleta MOA: first-in class pleuromutilin that inhibits protein synthesis via binding to peptidyl transferase center of 50S ribosomal subunit ROA: PO, IV Typical indications: ?? AVEs: D/N, injection site rxns Warnings: pregnancy (teratogenic), QT prolongation CIs: use w/ CYP3A4 substrates that prolong QT interval

Answer 56

Brand: Dificid MOA: inhibits RNA polymerase, inhibiting protein synthesis and cell death Typical indication: C. diff AVEs: N/V, abdominal pain, GI bleeding, anemia Warnings: NOT effective for systemic infections (absorption minimal)

Answer 57

Brand: Xifaxan MOA: inhibits bacterial RNA synthesis vial binding to DNA-dependent RNA polymerase ROA: PO Typical indications: traveler's diarrhea, hepatic encephalopathy, IBD-D -NOT effective for systemic infections (<1% absorption) -Off label: C. difficle (third or subsequent recurrence) AVEs: peripheral edema, dizziness, HA, nausea, abdominal pain, rash, pruritus

Answer 58

Brand: Monurol MOA: inactivates enzyme, pyruval transferase which is critical in synthesis of cell walls -Concentrates in urine Dose: packet granules (3 grams/packet) --> 3 grams PO once mixed in 3-4 oz of cold water Coverage: E. coli (including ESBL), E. faecalis (including VRE) Typical indication: uncomplicated UTI AVEs: HA, D/N

Answer 59

Brand: Macrobid, Macrodantin MOA: bacterial cell wall, DNA, RNA, and protein synthesis inhibitor ROA: PO Typical indication: uncomplicated UTI (cystitis only; E. coli, Klebsiella, Enterobacter, S. aureus, Enterococcus including VRE) Dosing: -Macrobid: 100mg PO BID x5D -Macrodantin: QID AVEs: GI upset (take CF), HA, rash, brown urine discoloration (harmless) Warnings: optic neuritis, hepatotoxicity, peripheral neuropathy, pulmonary toxicity, G6PD deficiency (hemolytic anemia - do NOT use if known deficiency) CIs: -Renal impairment (CrCl <60mL/min): inadequate urine concetration and risk for accumulation of neurotoxins -Hx of cholestatic jaundice/hepatic dysfunction -Pregnancy

Answer 60

Brand: Bactroban Nasal ointment to eliminate MRSA colonization of nares

Answer 61

-Dicloxacillin, nafacillin, oxacillin -1st and 2nd gen cephalosporins (ex. cephalexin, cefazolin) -Augmentin, ampicillin/sulbactam

Answer 62

MRSA: vancomycin (consider alternative if MIC 2 or greater), linezolid, daptomycin (NOT for pneumonia), ceftaroline CA-MRSA: SMX/TMP, doxycycline, clindamycin

Answer 63

E. faecalis only: penicllin G, ampicillin Cystitis: nitrofurnaoint, fosfomycin, doxycycline Others: linezolid, daptomycin

Answer 64

azithromycin, clarithromycin, doxycycline, minocycline, quinolones

Answer 65

-Beta-lactam/beta-lactamase inhibitors -Cephalosporins (1st gen covers PEK) - Carbapenems -Aminogylcosides, quinolones, Bactrim

Answer 66

-Piperacillin/tazobactam, cefepime, ceftazidime, ceftazidime/avibactam, ceftolozane/tazobactam, carbapenems (except: ertapenem) -Ciprofloxacin, levofloxacin, aztreonam, tobramycin

Answer 67

piperacillin/tazobactam, cefepime, carbapenems, aminoglycosides

Answer 68

carbapenems, ceftazidime/avibactam, ceftolozane/tazobactam

Answer 69

ceftazidime/avibactam, colistimethate, polymyxin B, meropenem/vaborbactam, imipenem/cilastatin/relebactam

Answer 70

metronidazole, beta-lactam/beta-lactamase inhibitor, cefotetan, cefoxitin, carbapenems, moxifloxacin (reduced activity)

Answer 71

vancomycin (PO), fidaxomicin, metronidazole

Answer 72

Refrigerate, required: penicilin VK, Augmentin, cephalexin, cefadroxil, cefpodoxime, cefprozil, cefuroxime, cefaclor, fidaxomicin, vancomycin PO, valganciclovir Refrigerate, recommended: amoxicillin (improves taste), oseltamivir (increases shelf-life) Do NOT refigerate: cefdinir, azithromycin, clarithromycin, clilndamycin, doxycycline, erythromycin, ciprofloxacin, levofloxacin, linezolid, metronidazole, nitrofurantoin, Bactrim, acyclovir, fluconazole, itraconazole, posaconazole, voriconazole, nystatin

Answer 73

1. Metronidazole 2. Moxifloxacin 3. Bactrim 4. Acyclovir

Answer 74

1. Anti-staphylococcal PCNs (ex. dicloxacillin, nafcillin) 2. Azithromycin, erythromycin 3. Ceftriaxone 4. Clindamycin 5. Doxycycline 6. Metronidazole 7. Moxifloxacin 8. Linezolid

Answer 75

1. Ampicilllin oral caspules 2. Levofloxacin oral solution 3. Pencillin VK 4. Tetracycline 5. Doxycycline (Oracea brand) 6. Rifampin 7. Isoniazid 8. Itraconazole oral solution 9. Voriconazole

Answer 76

1. Azithromycin 2. Levofloxacin, moxifloxacin 3. Doxycycline, minocycline 4. Linezolid, tedizolid 5. Metronidazole 6. Bactrim

Answer 77

Bactrim, AmpB, pentamidine

Answer 78

ampicillin, ampicillin/sulbactrim, ertapenem

Answer 79

caspofungin, daptomycin

Answer 80

1. Doxcycline 2. Micafungin 3. Pentamidine

Answer 81

1. Gram positive cocci (staphylococci and streptococci) --> in select surgeries such as intra-abdominal, gram-negative and anerobes 2. -Cardiac or vascular: cefazolin or cefuroxime (preferred), clindamycin or vancomycin (beta-lactam allergy) -Orthopedic: cefazolin (preferred), clindamycin or vancomycin (beta-lactam allergy) -GI: cefazolin + metronidazole, cefotetan, cefoxitin, or ampicillin/sulbatam (preferred), clindamycin or metronidazole + aminoglycoside or quinolone (beta-lactam allergy) 3. -Before: cefazolin or cefuroxime within 60 minutes of first incision; quinolone or vancomycin 120 minutes of first incision -During: additional dose may be given for longer surgeries (>4 hours) or major blood loss --> ex. cefazolin T1/2 = 2 hours, redose Q4H -After: NOT usually needed (if used, D/C within 24 hours)

Answer 82

S/Sx: fever, HA, nuchal rigidity (stiff necK), altered mental status -Other s/sx: chills, vomiting, seizures, characteristic rash, photophobia Diagnosis: lumbar puncture (LP) - culture of cerebrospinal fluid (CSF), high CSF pressure ("opening pressure") may also indicate infection -Bacterial CSF: elevated WBCs and protein, decreasd glucose Pathogens: menigitis is typically viral, but for bacterial: -GP: cocci (groupB strep, Streptococcus pneumonia) -GN: cocci (N. meningitidis), coccobacilli (H. influenzae), bacilli (E. coli) -Listeria monocytogenes: higher risk in neonates, pts >50 yo, and immunocompromised

Answer 83

Dexamethasone IV: aminister 15-20 minutes prior to ABXs or with first dose to prevent neurological complications (ex. hearing loss) and death from excessive inflammation--> during empiric therapy, appropriate to adminster to all pts since causative species NOT known -D/C if species to be identified is NOT S. pneumoniae Empiric TX: higher doses, must penetrate BBB -Age <1 month (neonates): ampicillin (Listeria coverage) + cefotaxime, ceftazidime, or cefepime +/- gentamicin -Age 1 month - 50 yo: ceftriaxone + vancomycin -Age > 50 yo: ampicillin (Listeria coverage) + ceftriaxone + vancomycin Duration of TX: -N. meningitidis, H. influenzae: 7 days -S. pneumoniae: 10-14 days -GroupB strep (S. agalactiae): 14-21 days -L. monocytogenes, GNRs: at least 21 days

Answer 84

S/Sx: rapid onsets of bulging tympanic (eardrum) membranes, otorrhea (middle ear effusion/fluid), otalgia (ear pain), fever, crying, tugging/rubbing ears Pathogens: mostly caused by viruses, but for bacterial: -S. pneumoniae, H. influenzae, or Moraxella catarrhalis Observation: for 2-3 days if symptoms are non-severe (otalgia <48 hours, no otorrhea, temp <102.2F or 39C) AND -Age 6-23 months: symptoms in one ear only -Age 2 yo or older: symptoms in one or both ears -ALWAYS treat <6 months TX: higher doses to penetrate ear -First line: amoxicillin 90mg/kg in 2 divided doses OR Augmentin 90mg/kg with 6.4mg/kg/day of clavulanate in 2 divided doses (keep ratio of amoxicillin:clavulanate 14:1 to minimize toxicity) -Alternatives (non-severe PCN allergy: mild, non-itchy rash): cefdinir, cefuroxime, cefpodoxime, or ceftriaxone -TX failure (no imporvement after 2-3 days): Augmentin if amoxicillin failed or ceftriaxone IM

Answer 85

Pathogen: respiratory viruses (rhinovirus, seasonal coronavirus) S/Sx: sneezing, runny nose, mild sore throat, cough, congestion -Fever usually absent or low-grade (<101F), no myalgias Criteria for TX: non --> generally resolves within a few days TX: symptomatic care (analgesics, decongestants, cough suppressants, expectorants, and.or antihistamines)

Answer 86

Pathogen: influenza virus S/Sx: sudden onset fever, chillls, fatigue, myalgia, dry cough, sore throat, HA -Symptoms are more severe than a common cold Criteria for TX: suspected or confirmed infection AND -Symptoms <48 hours OR -Severe illness OR -Symptoms plus risk factors for complications TX: symptomatic care +/- antivirals (oseltamivir, baloxavir marboxil)

Answer 87

Pathogen: respiratory viruses, group B strep (S. pyogenes) S/Sx: sore throat, fever, swollen lymph nodes, white patches (exudates) on tonsils -Absence of runny nose, cough, or congestion Criteria for TX: rapid antigen test (tonsil swab) or thorate culture (+) for S. pyogenes TX: penicillin VK or amoxicillin -Mild PCN allergy: 1st or 2nd gen cephalosporin -Severe rxn to PCN: macrolide (clarithyromycin, azithromycin) or clindamycin

Answer 88

Pathogen: respiratory viruses (S. pneumoniae, H. influenzae, M. catarrhalis) S/Sx: nasal congestion, purulent nasal discharge, facial/ear/dental pain or pressure, HA, fever -Absence of cough Criteria for TX: -10 days or longer w/ persistent symptoms OR -3 days or longer w/ severe symptoms (face pain, purulent nasal discharge, temp >102F) OR -Worsening symptoms after initial improvement TX: Augmentin or symptomatic care for up to 7 days w/ decongestants, antihistamines, expectorants, and/or analgesics -Macrolides NOT recommended due to poor coverage of S. pneumoniae

Answer 89

S/Sx: non-productive or productive cough lasting 1-3 weeks, chest wall tenderness, wheezing, rhonci -Systemic symptoms (fever, chills, mailase) are rare Pathogen: Usually preceded by URTI virus (ex. rhinovirus, coronavirus, influenza) -Rarely bacterial: S. pneumoniae, H. influenzae, atypicals (Myclopasma pneumonae) Diagnosis: ruling out other causes; chest x-ray is typically normal TX: ABXs are NOT recommended (self-limiting), supportive care

Answer 90

S/Sx: -Catarrhal phase (week 0-2): mild cough/rhinitis -Paroxysmal phase (week 2-8): severe bouts of coughing (whooping cough) -Convalescent (week 8-12+): gradual resolution Pathogen: Bordetella pertussis Diagnosis: nasopharyngeal swab culture or PCR TX: highly contangious --> treat w/ macrolides (azithromycin, clarithromycin)

Answer 91

S/Sx: increased dsypnea, increased sputum volume, increased sputum purulence -Symptoms that necessitates a change in COPD medications Pathogen: H. influenzae, M. catarrhalis, S. pneumoniae -Other causes: environmental pollution Diagnosis: increase in symptoms that worsen over <14 days TX: supportive TX (oxygen, short-acting inhaled brochodilators, IV or PO steroids, ABXs (Augmentin, aizthromycin, doxycycline, or respiratory quinolone) for 5-7 days IF on one of the following: -All three symptoms present (dyspnea, sputum volume, sputum purulence) -Increased sputum purulence with an additional symptom -Mechanically ventilated

Answer 92

S/Sx: SOB, fever, cough with purulent symptoms, pleurtic chest pain, rales, tachypnea, decreased heart sounds, elevated WBCs Pathogen: S. pneumoniae, H. influenzae, M. pneumoniae, C. pneumoniae, Legionella Diagnosis: chest X-ray - inflitrates/opacities/consolidations

Answer 93

-Healthy, no comorbidities: amoxicillin high dose (1 gram TID) OR doxycycline OR macrolide (azithromycin or clarithromycin) if local pneumococcal resistance is <25% -High risk (with comorbidities): beta lactam (Augmentin, cefpodoxime, cefuroxime) + macrolide or doxycycline OR respiratory quinolone monotherapy (moxifloxacin or levofloxacin) **Comorbodities: chronic heart, lung, liver, or renal disease; DM; alcohol use disorder; malignancy; asplenia **Erythromycin: NOT recommended due to poor tolerance and DDIs TX duration: 5-7 days usually

Answer 94

-Non-severe (admission to general medicine unit): beta lactam (ceftriaxone, ceftaroline, ampicillin/sulbactam) + macrolide or doxycycline OR respiratory quinolone monotherapy -Severe (admission to ICU): beta lactam + macrolide OR beta-lactam + respiratory quinolone (NO quinolone monotherapy) -Risk for MRSA (prior respiratory isolation or positive nasal swab): add vancomycin or linezolid -Risk for Pseudomonas (prior respiratory isolation): beta-lactam w/ Pseudomonas activiy (ex. piperacillin/tazobactam, cefepime, ceftazidime, imipenem/cilastin, meropenem) -Hospitalization and use of parenteral ABXs in past 90 days: use regimen active against both MRSA and Psuedomonas TX duration: 5-7 days usually

Answer 95

HAP: onset >48 hours after hospital admission VAP: occurs >48 hours after start of mechanical ventilation S/Sx: SOB, cough w/ purulent sputum, pleuritic chest pain, fever, elevated WBCs -Chest X-ray: consolidation or infiltrates -Physical exam: rales, tachypnea, decreased breath sounds -Additional VAP signs: increased secretions (suction requirements), increased ventilation needs (FiO2) Pathogen: nosocomial (MSSA, MRSA, Pseudomonas, MDR GNRs risk - E. coli, Acineobacter, Enterbacter) Empiric TX: ALL need MSSA and Pseudomonas coverage (ex. cefepime, piperacillin/tazobactam, levofloxacin) -MRSA risk (IV ABX use in past 90D, MRSA prevalence in hospital unit >20% or unknown, prior MRSA infection, or positive MRSA nasal swab): add vancomycin or linezolid -Use two ABXs for Pseudomonas if risk for MDR GNR (IV ABX use in past 90D, prevalance in hospital unit >10%, hospitalized 5 days or more prior t onset of VAP): beta-lactam + other agent (don't use TWO beta-lactams for Pseudomonas - fluroquinolone, aminoglycoside)

Answer 96

Pathogen: Mycobacterium tuberculosis Tuberculin skin test (TST) also called purfied protein derivative (PPD) test: intradermal solution injected and inspected for induration (raised area) 48-72 hours later, positive IF: -Close contact of active TB, HIV infection, immunosuppression: 5mm or greater induration -Immigrants w/ high burden countries, clinical risks (IV drug use, DM), residents/employees of high-risk congregate settings (prisons, healthcare facilities, homeless sheltors): 10mm or greater induration -Pts with NO risk factors: 15mm or greater induration IGRA blood test: preferred in pts w/ hx of BCG vaccination Transmission: NOT contagious as latent

Answer 97

Shorter duration (3-4 months) preferred due to higher completion rates and less hepatotoxicity risk -INH + rifapentine Qweekly x12 weeks via directly observed therapy (DOT) or self-administered (do NOT use in pregnancy: fetal risk unknown w/ rifapentine) -INH + rifampin QD x3 months -Rifampin QD x4 months -INH QD x6-9 months (may be preferred in HIV - less DDIs, 9 months recommended) **Rifamycin-based regimens: check for DDIs

Answer 98

S/Sx: cough > 2-3 weeks in duration, hemoptysis, purulent sputum, fever, night sweats, unintentional weight loss Transmission: highly contagious via aerosolized droplets (hospitalization requires negative-pressure room and masks for healthcare workers) Diagnosis: sputum culture or PCR (BUT slow to grow - could take 6 weeks), acid fast bacilli (AFB) smear (NOT selective for TB), chest x-ray w/ consolidation or cavitation (empty space) to confirm positive TST or IGRA

Answer 99

TX: -Intensive phase: four drugs (RIPE: rifampin, isoniazid, pyrazinamide, ethambutol) x 2 months -Continuation phase: two drugs (commonly rifampin and isonazid) x 4 months -Direct observed therapy (DOT) used to increase medication adherence and preferred in certain populations (homless, drug-resistant disease, poor adherence, positive sputum smearsa nd delayed culture positivity) --> alternative dosing regimens (ex. 2-3x/week) can be used TX in resistance: -MDR-TB: resistant to BOTH rifampin or INH (second line drugs up to 24 months: quinolones - moxifloxacin or levofloxacin, injectables - streptomycin, amikacin, or kanamycin) -XDR-TB: bedaquiline can be sued (BBW: QT prolongation and increased risk of death), pretomanid (approved for both MDR-TB and XDR-TB in combo w/ bedaquiline and linezolid - many AVES: peripheral neuropathy, optic neuropathy, myleosuppression, QT prolongation)

Answer 100

Isonazid: -Use pyroxidine (vitamin B6) 25-50mg QD to decrease risk of INH-associated peripheral neuropathy -AVEs: increased LFTs, DILE, hemolytic anemia (positive Coombs test) -BBW: hepatitis (severe and fatal) Pyrazinamide: -AVEs: increased LFTs, hyperuricemia/gout, GI upset, malaiase, arthralgia, rash -CI: acute gout, severe hepatic damage Ethambutol: -AVEs: increased LFTs (dose-related), confusion, hallucinations, decreased visual acuity, partial loss of vision/blind spot and/or color blindness (usually reversible) -CI: optic neuritis

Answer 101

Brand: Rifadin AVEs: increased LFTs, hemolytic anemia (positive Coombs test), flu-like syndrome, GI upset, rash/pruritus -Orange-red discoloration of body secretions (saliva, urine, sweat, tears): can stain contact lenses, clothing, and bedsheets CI: concurrent use w/ protease inhibitors DDIs: potent inducer of CYP1A2, 2C8, 2C9, 2C19, 3A4, and P-gp -Decreases: protease inhibitors (substitute rifabutin), warfarin (very large decrease in IRN common - need large dose increases), OCs (requires backup contraception method) -do NOT use w/ apixiban, rivaroxaban, edoxaban, or dabigatran (failure of therapy) -Always screen for DDIs -Rifabutin has fewer interactions and can replace rifampin in some cases

Answer 102

SBP: infection of peritoneal space that often occurs in pts w/ cirrhosis and ascites -Paracentesis: ascitic fluid sample >/=250 cells/mm3 PMN (polymorphonuclear leukocytes) Emperic TX: ceftriaxone or cefotaxmine x5-7D (targets most likely pathogens: steptococci, Proteus, E. coli, Klebsiella Alternative: carbapenem in critically ill or risk for MDR Secondary prophylaxis: ALL pts who have received initial SBP epsidoe should be prescribed Bactrim or quinolone to decrease subsequent infections (also indicated in ascitic fluid protein <1.5g/dL and impaired renal or heaptic function)

Answer 103

Other intra-abdominal infections: appendicitis, cholecystitis (inflammation of gallbladder), cholangitis (inflammation of bile duct), secondary peritonitis, diverticulitis -If abcess present, drain (source control) -Infections usually polymicrobial (streptococci, enteric gram-negatives, anaerobes - ex. Bacterioides fragilis): often a single ABX (if NO anaerobe coverage, add metronidazole) for 4-5 days until source control accomplished -Risk of MDR pathogens (critically ill, hospitalized >48 hours, ABX in past 90D): consider coverage of Psedumonas or other resistant organisms General TX Options: -Cover PEK, anaerobes, and streptococci (low risk): ertapenem, moxifloxacin, cefuroxime or ceftriaxone + metronidazole, ciprofloxacin or levofloxacin + metronidazole -Cover PEK, Pseudomonas, Enterobacter, anaerobes, streptococci, and entercocci (high risk: critically ill, received ABXs in past 90 days, or known colonization of prior infection) : carbapenem (except ertapenem), piperacillin/tazobactam, cefepime or ceftazidmine + metronidazole

Answer 104

S/Sx: fever w/ or w/o heart murmur, signs of thromboembolism, elevated WBCs Pathogen: Staphylococci, Streptococci, and Enterococci Diagnosis: echocardiogram (vegetation on valve) and positive blood cultures TX challenges: vegetation acts as a protective film - difficult for ABXs to penetrate, high concentration of bacteria present, and slow rate of bacterial growth

Answer 105

Empiric TX: often includes vancomycin + ceftriaxone Definitive TX: -Viridans group streptococci: PCN or ceftriaxone +/- gentamicin (beta-lactam allergy: use vancomycin monotherapy) -MSSA: nafcillin or cefazolin + gentamicin and rifampin if prosthetic valve (beta-lactam allergy: vancomycin +/- gentamicin and rifampin ---> prosthetic valves) -MRSA: vancoymcin + gentamicin and rifampin if prosthetic valve -Enterococci: for both naive and prosthetic valve, PCN or ampicillin + gentamicin OR ampicillin + high-dose ceftriaxone (beta-lactam allergy: vancomycin + gentamicin, VRE: daptomycin or linezolid) **Gentamicin added for synergy (beta lactam penetrates cell wall, allowin gentamicin to enter to work) in infections more difficult to eradicate (peak level: 3-4 mcg/mL, trough <1 mcg/mL)

Answer 106

Dental prophylaxis: indicated in pts with dental work needed (manipulation of gingival tissue or near root of tooth - tooth extraction, root canal, abscess drainage) + select cardiac conditions (ex. artificial/prosthetic heart valve or heart valve repiared w/ artifical material, hx of endocarditis, heart transplant w/ abnormal heart valve function, certain congenital heart defects including heart/heart valve disease) -ALL: give as single dose 30-60 minutes prior to dental procedure -First-line: amoxicillin 2 grams PO -Unable to take PO: ampicillin IV/IM OR cefazolin or ceftriaxone IM/IV -PCN allergy: azithromycin or clarithromycin PO OR doxycycline PO

Answer 107

Superficial infection Pathogen: Group A streptococcus (mostly S. pyogenes), S. aureaus (most often MSSA) S/Sx: blister-like rash (may be itchy or painful) usually around nose, mouth, hands, or arms; pustules rupture and produce thick-yellowish, clear fluid that dries and forms honey-colored crusts over area -Common in children TX: warm, wet compresses to remove dried crusts (do NOT share towels, sheets, or clothing and wash in hot water) -Limited, localized: apply topical ABX usually mupirocin (alternatives: retapumulin - Altabax, ozenoxacin -Xepi) -Numerous, extensive lesions: cephalexin or dicloxacillin

Answer 108

Superficial infection Pathogen: S. aureus, including CA-MRSA S/Sx: -Folliculitis: inflammation in hair follicles (red pimples) -Furuncle (boils): purulent infection of hair follicle -Carbuncle: group of infected furuncles TX: -Small furuncles, folliculitis: warm compresses to decrease inflammation and improve drainage -Large furuncles, carbuncles: incision and drainage +/- ABXs (Bactrim or doxycline) -Occassionally, folliculitis is due to fungal infection and can be treated w/ ketoconazole cream

Answer 109

NO - penetrates subcutaneous tissue Pathogens: Streptococci including S. pyogenes (GRoup A Streptococcus), S. aureus -Purulent more often S. aureus (MSSA or MRSA) S/Sx: occurs on legs, generally unilateral, but can rapidly spread/expand -Mild symptoms: localized pain, swelling, redness, warmth TX: ABX should be active against streptococci and MSSA --> must have NO signs of systemic s/sx (WBCs /=4000; temp

Answer 110

Pathogen: S. aureus, including CA-MRSA S/Sx: initially appears as localized fluid collection TX: source control -ABXs with MSSA and MRSA coverage: Bactrim, doxycycline, minocycline, clindamycin, linezolid -If culture shows just MSSA: cephalexin -If recurrent MRSA infections, consider nasal decolonization w/ nasal mupirocin and skin decolonization w/ chlorhexidine or diluent bleach

Answer 111

Severe purulent: ABXs w/ MRSA activity (vancomycin w/ goal trough of 10-15 mcg/mL, daptomycin, linzeolid) -Alternatives: ceftaroline, tedizolid, televancin -Once clinically stable, transition to PO ABXs -Duration of therapy 7-14 days Necrotizing Fascilitis: life-threatening and fast-moving that can destroy tissue and penetrate down into muscle --> emergency TX in hospital -Urgent surgical debridement -Broad empiric ABXs: vancomycin or daptomycin + beta-lactam (piperacillin/tazobactam, meropenem) + clindamycin (to suppress streptococcal toxin production)

Answer 112

Pathogens: -Aerobic: S. aureus (including MRSA), Group A streptococcus, Viridans group streptococci, S. epidermidis, E. coli, Klebsiella pneumoniae, Proteus mirabilis, Enterobacter clocacae, Pseudomonas (if significant water exposure) -Anaerobic (if limb ischemia or necrosis present): Peptostreptococcus, C. perfringens, Bacteriodies fragilis and others Mild: w/o systemic symptoms --> can treat similarily to mild SSTIs Moderate-severe: start IV then transition to PO -NO MRSA activity needed: ampicillin/sulbactam, ertapenem, ceftriaxone, levofloxacin or moxifloxacin -Pseudomonas and/or MDR gram-negative activity needed: piperacillin/tazobactam, cefepime, meropneem, doripenem, or imipenem/cilastin -MRSA activity needed: add vancomycin, daptomycin, or linezolid -Anaerobic activity needed: use regimen w/ anaerobic activity (ex. beta-lactam/beta-lactamase, carbapenem) OR add metronidazole TX duration in moderate-severe: -NO bone involvement: 2-4 weeks -Osteomyelitis: 4-6 weeks, typically with IV ABXs -Amputation w/ no residual infection: 2-5 days

Answer 113

Lower (bladder and urethra) and uncomplicated UTI S/Sx: urgency and frequency, nocturia, dysuria, suprapubic tenderness, hematuria Pathogen: mostly E. coli; others: Proteus, Kelbsiella, Staphylococcus saphrophyticus, enterococci Diagnosis: urinalysis with pyruira (WBC elevation), bacteria, and positive leukocyte esterase +/- nitrates (E. coli, Proteus, Klebsiella) -Prescence alone of bacteria does NOT indicate UTI or need for TX

Answer 114

TX: usually empiric as outpatient -DOC: nitrofurantoin (Macrobid) 100mg PO BID x5D (CI if CrCl <60mL/min), Bactrim DS 1 tablet PO BID x3D (avoid in sulfa allergy or >/=20% E.coli resistance rate), or fosfomycin x 1 dose -Alternatives: beta-lactam (Augmentin or cephalosporin x5-7D, ciprofloxacin x3D, levofloxacin x3D) -Pregnancy (ALWAYS treat even if asymptomatic): amoxicillin +/- clavulanate, cephalexin; beta-lactam allergy: fosfomycin, Bactrim, nitrofurantoin --> treat for 7 days **Quinolones: do NOT use in children, pregnancy (cartilage toxicity and arthropathies), those w/ seizures/neuropathy/QT prolongation risk **Moxifloxacin: do NOT use for UTIs (does NOT reach high enough urine levels) **Bactrim and nitrofurantoin: only use in pregnancy if other options not available due to potential fetal risk Prophylaxis: 3 or more episodes in one year --> can use Bactrim SS 1 tablet QD, nitrofurantoin 50mg PO QD, or Bactrim DS 1 tablet after sexual intercourse

Answer 115

Upper UTI (kidneys), complicated (men with UTIs automatically is complicated) S/Sx: flank/costovertebral angle pain, abdominal pain, N/V, fever, chills, malaise +/- cystitis symptoms Pathogen: E. coli, Proteus, or Klebsiella -Less common: Enterobacter, Serratia, Pseudomonas, enterococci Diagnosis: urinalysis with pyruira (WBC elevation), bacteria, and positive leukocyte esterase +/- nitrates (E. coli, Proteus, Klebsiella) -Prescence alone of bacteria does NOT indicate UTI or need for TX

Answer 116

Outpatient TX: ciprofloxacin or levofloxacin or Bactrim Moderately ill TX: -If local quinolone resistance >10%: ceftriaxone IV/IM, ertapenem IV/IM, or aminoglycoside extended interval IV/IM then continue with a quinolone as above -Concern for quinolone AVEs: beta-lactam (Augmentin, cefdinir, cefadroxil, or cefpodoxime) or Bactrim x7-10D Severely ill TX: -Initial: ceftriaxone or quinolone (ciprofloxacin or levofloxacin) -Concern for resistance (prior isolation on culture, urinary instrumentation, recent healthcare exposure, broad spectrum ABXs in past 3 months): piperacillin/tazobactam or carbapenem (if ESBL-producing organism suspected) -Pseducomonas risk of documented infection: anti-pseudomonal carbapenem -Last line: cefiderocol, imipenem/cilastin/relebactam, meropenem/vaborbactam, plazomicin -Step down to PO TX based on culture and susceptiblity -TX duration for 5-10D based on regimen and clinical response

Answer 117

Brand: Pyridium (RX), Azo Urinary Pain Relief (OTC) ROA: PO Administration: -Available OTC and RX -Take with 8oz of water with or immediately following food to minimize stomach upset -Use for two days maximum TX: urinary analgesic AVEs: HA, dizziness, stomach cramps, body secretion discoloration (red-orange of urine or other fluids --> can stain clothing and contact lenses), hemolytic anemia (G6PD deficiency) CI: renal impairment or liver disease

Answer 118

S/Sx: at least three watery stools per day, abdominal cramps, fever, elevated WBCs, impaired renal fxn Risk factors: healthcare exposure, PPIs, advanced age, immunocrompromised state, obesity, previous CDI, recent ABXs Complications: inflammation of colon can lead to pseudomembranous colitis which can progress to toxic megacolon Transmission: fecal-oral -Precautions: hand hygiene (soap and water), gloves/gown, isolation, ABX stewardship Diagnosis: positive C. difficle stool toxin or PCR, positive stool test (nucleic acid amplicifaction test =NAAT) -Nonsevere: WBC <15000 + SCr <1.5 -Severe: WBC >/=15000 + SCr > 1.5 -Fulminant: hypotension, shock, ileus, toxic megacolon

Answer 119

TX: D/C unecessary ABXs or other possible caustive agents (ex. PPIs) -First episode: fidaxomicin 200mg PO BID X10D or vancomycin 125mg PO QID x10D (metronidazole only if non-severe and other treatment unavailable) -Second episode: fidaxomicin 200mg PO BID x10D or vancomycin (prolonged taper acceptable if metronidazole used for initial episode) -Third or subsequent episodes: fidaxomicin or vancomycin followed by prolonged taper or standard regimen followed by rifaximin 400mg TID x20D or fecal microbiota transplantation -High risk pts (age >/=65 yo, immunocompromised, severe presentation, and/or hx of CDI in past 6 months): adjunct bezlotuxumab (MAB that binds to toxin B and neutralizes its effects) --> caution in heart failure Fulminant/complicated disease: vancomycin 500mg PO/NG/PR QID + metronidazole 500mg IV Q8H -Surgical evaluation for colectomy

Answer 120

Pathogen: Treponema pallidum (corkscrew-shaped) Diagnosis: nontreponemal test (VDRL, RPR) + treponemal test (various) Primary (chancre), secondary (rash, lymphadenopathy), or early latent syphilis (asymptomatic, acquired likely -Early latent: acquired within past year (asymptomatic) -DOC: pencillin G benzathine (Bicillin L-A -> do NOT substitute w/ Bicilllin C-R) 2.4 million units IM x1 -Beta-lactam allergy: doxycycline BID x14D, consider densitization if pregnancy, nonadherent w/ TX or unlikely to follow up Late latent or tertiary syphillis: -Late latent: acquired >1 year ago or unknown duration, asymptomatic -Tertiary: CV or CNS manifestations -TX: same as primary, secondary, or early latent syphilis (except alternative doxycycline for 28 days) Neurosyphilis (altered mentation, motor/sensory dsysfunction, s/sx of meningitis): can occur at any stage -DOC: penicillin G aqueous crystalline IV -Alternatives: penicillin G procaine, densensitization followed by administration of penicilin G aqueous IV in beta-lactam allergy **For desensitization, confirm allergic rxn with skin test first --> required in neurosphyilis, pregnancy, and expected supotimal adherence to doxycycline

Answer 121

Pathogen: Neisseria gonorrhoeae S/Sx: -Males: urethral discharge, dysuria, or asymptomatic -Females: commonly asymptomatic --> vaginal pruritus and mucopurulent cervical discharge Diagnosis: urethral, vaginal, cervical, rectal, and/or pharyngeal swabs TX: -DOC: ceftriaxone 500mg IM if pt <150kg (1gm in 150kg or greater) -If chylamdia has NOT been excluded, add doxycycline -Alternatives: cefixime PO if ceftriaxone NOT available, gentamicin or azithromycin is cephalosporin allergy -Pharyngeal infections: ceftriaxone is MOST effective (in severe allergy, consult ID specialist)

Answer 122

Pathogen: Chlamydia trachomatis Diagnosis: urethral, vaginal, cervical, rectal, and/or pharyngeal swabs TX: -DOC: doxycycline 100mg PO BID x7D (if pregnant: azithromycin 1g PO x1) -Alternatives: erythromycin base PO, levofloxacin PO, or amoxicillin PO in pregnancy

Answer 123

S/Sx: vaginal discharge (clear, white, or gray) that has a "fishy" odor and pH >4.5, little or no pain Pathogen: many different organisms, including Gardnerella vaginalis TX: -DOC: metronidazole x7D OR metronidazole gel x5D OR clindamycin x7D -Alternatives: clarithromycin PO or ovules OR tinidazole PO OR secnidazole -Females should NOT douche

Answer 124

S/Sx: yellow/green, frothy vaginal discharge w/ pH >4.5; soreness, pain w/ intercourse Pathogen: Trichomonas vaginalis TX: -DOC: metronidazole x7D (females) or x1 (males) -Preganncy: metronidazole CI in 1st trimester, but based on additional safety data and AVEs with infections, CDC recommens metronidazole in ALL trimesters

Answer 125

Pathogen: Human papillomavirus (HPV) strains 6 & 11 S/Sx: single or multiple pink or skin-colored lesions that range from smooth, flattened papules to cauliflower-like growths TX: -DOC: imiquimod cream -TX NOT required if asymptomatic (warts generally resolve spontaneously within one year) -Imiquimod can weaken condoms and diaphragms and irritate anogenital mucosa (abstain from sexual activity while cream is on skin) Prevention: Gardasil vaccine

Answer 126

-Pathogen: Rickettsia rickettsii -Can be fatal (s/sx: muscle pain, HA, fever then followed 3-5 days later by erythematous petechial rash - red spots caused by bleeding into the dermis) -TX: doxycycline PO/IV x5-7D (DOC including in pediatric pts

Answer 127

-Pathogen: Borrelia burgodorferi, Borrelia mayonii -S/Sx: early (<1 month) erythema migrains and flu-like syndrome, late: disseminated disease and organ dysfunction or chronic disorders (arthritis) -TX: doxycycline BID x10D OR amoxicillin PO x14D OR cefuroxime PO x14D -Severe: IV ceftriaxone

Answer 128

-Pathogen: Ehrlichia chaffeensis -S/Sx: round, "bull's eye", rash (uncommon), confusion -TX: doxycycline PO/IV BID x7-14D

ID - Bacterial Infections / ABXs Flashcards

(152 cards)