Infections Flashcards
(106 cards)
1
Q
What are some causes of drug antibiotic resistance?
A
- Recent use of antibiotics
- Overuse of broad-spectrum antibiotics
- Over prescription of antibiotics for viral illness, simple URIs, sinusitis, bronchitis
- Age less than 2 years or greater than 65 years
- Daycare center attendance
- Exposure to young children
- Multiple medical comorbidities
- Immunosuppression
2
Q
Vaccination with which vaccine has helped to decrease antimicrobial resistance to antibiotics?
A
Pneumococcal vaccine
3
Q
What are some common organisms for the following diagnoses?: eye infections, bacterial meningitis, otitis media, sinusitis, URI, gastritis, food poisoning, STIs, UTIs
A
- Eye infections: s. aureus, n. gonorrheae, chlamydia trachomatis
- Bacterial meningitis: strep pneumonia, n. meningitidis, h. influenzae, s. agalactiae, listeria monocytogenes
- Otitis media: strep pneumoniae
- Sinusitis: strep pneumoniae, h. influenzae
- URI: strep. Pyogenes, h. influenzae
- Gastritis: h. pylori
- Food poisoning: campylobacter jejuni, salmonella, shigella, clostridium, s. aureus, e. coli
- STIs: chlamydia trachomatis, n. gonorrhoeae, treponema pallidum, ureplasma urealyticum, h. ducreyi
- UTIs: e. coli, other enterobacteriaecae, s. saprophylicus, p.aeruginosa
4
Q
What are some common organisms that cause community acquired, atypical and TB pneumonia?
A
- Community acquired: s. Pneumoniae, h. influenzae, s. aureus
- Atypical: Mycoplasma pneumoniae, chlamydia pneumoniae, legionella pneumophilia
- TB: mycobacterium tuberculosis
5
Q
What are some common organisms that cause skin infections? Impetigo?
A
s. aureus, s. pyogenes, pseudomonas aeruginosa
Impetigo: s. aureus and streptococcus
6
Q
In what instances would you prescribe antibiotics?
A
- Empiric: based on evidence based guidelines
- Prophylactic: pretreating patients with implanted prosthetic devices
- Definitive: based on culture
7
Q
How long after starting an antibiotic will a patient usually feel relief of symptoms?
A
24-72 hours
8
Q
What are some examples of gram positive vs. negative organisms?
A
Gram positive: Staph aureus, strep pneumonia, clostridium
Gram negative: E coli, pseudomonas, h pylori, Neisseria gonorrhea, salmonella
9
Q
Which topical antibacterials can be used for mild cases of impetigo? (up to 5 lesions)
What is the target organism?
A
- Mupirocin (Bactroban, centany)
- bacitracin
- bacitracin + polymyxin B (double antibiotic)
- bacitractin + neomycin + polymyxin B (triple antibiotic)
Target organism: s. aureus
10
Q
What is the MOA of mupirocin?
A
Bactericidal, inhibits bacterial protein synthesis by binding to bacterial isoleucyl tRNA synthetase
11
Q
How many times should mupirocin be applied vs. bacitracin?
A
Mupirocin: 3x per day for 5-14 days
Bacitracin: 2-5 times per day until clear
12
Q
What patient education is needed for topical antibacterials against impetigo?
A
- Do not touch tip of the ointment container to the infected area, use glove if possible
- wash hands before/after
- do not share towels/utensils, wash with antibacterial soap
13
Q
What can be used to treat oral candidiasis?
A
- topical nystatin
- clotrimazole lozenges
14
Q
What can be used to treat vulvovaginal yeast infections?
A
- topical miconazole and clotrimazole
- one-time dose fluconazole
15
Q
What can be used to treat tinea infections?
A
- topical terbinafine
- miconazole
- ketoconazole
- clotrimazole
16
Q
What can be used to treat herpes simplex? What is the frequency of dosage?
A
- Topical acyclovir (Zovirax): every 3 hours x 7 days
- Penciclovir (Denavir) for herpes labialis: every 2 hours while awake
- Docosanol (Abreva): 5 times per day
17
Q
Beta-lactams
Penicillin V & Penicillin G Benzathine
What is the indication and what organisms do these medications target?
A
- Indication: Strep pharyngitis
- aerobic, gram positive organisms, including s. pneumoniae, group A beta-hemolytic strep (GABHS)
18
Q
Beta-lactams
Penicillin V & Penicillin G Benzathine
Which are the preferred diagnoses for treatment with these medications?
A
- Penicillin G is great against T. pallidum (syphilis)
- Penicillin V preferred for beta-hemolytic strep as G is an injectable with higher failure rate
19
Q
Beta-lactams
Penicillin V & Penicillin G Benzathine
Amoxicillin and Amoxicillin/clavulanic acid (Augmentin)
MOA - bacteriostatic or bactericidal?
A
- Inhibit the biosynthesis of peptidoglycan bacterial cell wall, causes cell wall death
- Bactericidal
20
Q
Beta-lactams
Penicillin V & Penicillin G Benzathine
What medications can be used to broaden the spectrum?
A
- Combination with beta-lactamase inhibitors to broaden their spectrum: clavulanate, sulbactam, tazobactam
21
Q
Beta-lactams
Penicillin V & Penicillin G Benzathine, Amoxicillin and Amoxicillin/clavulanic acid (Augmentin)
When to avoid, take caution, pregnancy/lactation and pediatrics considerations
A
- Avoid: hx of hypersensitivity reaction
- Caution: renal impairment
- Pregnancy/lactation: compatible
- Peds: approved
22
Q
Beta-lactams
Penicillin V & Penicillin G Benzathine; Amoxicillin and Amoxicillin/clavulanic acid (Augmentin
Adverse fx (6)
A
- GI: N/V/D, c. diff
- Candidiasis
- maculopapular rash within 7-10 days (most common with amoxicillin, does not indicate a true allergy - if pt has mono, more likely to have a rash if treated with amoxicillin)
- Rare anaphylaxis usually occurs within 2-30 minutes
- PCN G: pain at injection site
23
Q
Beta-lactams
Amoxicillin and Amoxicillin/clavulanic acid (Augmentin)
Indications of each (7 & 4)
A
- Amoxicillin: endocarditis prophylaxis, CAP, H. pylori, acute otitis media, sinusitis, lyme disease (children under 8), UTI in pregnancy
- Amoxicillin/clavulanic acid (Augmentin): COPD acute exacerbation, acute bacterial rhinosinusitis, CAP, bites
24
Q
Beta-lactams
Amoxicillin and Amoxicillin/clavulanic acid (Augmentin)
Target organisms
A
gram positive organisms, including s. pneumoniae, group A beta-hemolytic strep, enterococcus and greater activity against gram negative bacteria
25
Beta-lactams
Amoxicillin, Amoxicillin/clavulanic acid (Augmentin) & Penicillin V & Penicillin G Benzathine
Other considerations: pharmacokinetics
* Formulation tastes good
* Well absorbed from GI tract, several and unstable in acid - dicloxacillin and amoxicillin better absorbed than ampicillin
* Protein-bound, so good distribution
* Small amt is metabolized, most are excreted as unchanged drug in urine
26
Beta-lactams
1st generation cephalosporins: Cefazolin, cephalexin (keflex)
Indications & target organisms
* Indications: cellulitis, uncomplicated cystitis, impetigo, GABHS, strep pharyngitis
* Target organisms: gram positive cocci, methicillin-sensitive s. aureus, s. epidermis, streptococci, e. coli
27
Beta-lactams
All cephalosporins
MOA - bacteriostatic or bactericidal
inhibits mucopeptide synthesis in the bacterial cell wall synthesis during active multiplication, causing cell wall death; bactericidal
28
Beta-lactams
All cephalosporins
Pharmacokinetics
* oral formulations absorbed from GI tract
* widely distributed to most tissues
* some highly bound to proteins, some are metabolized to less active compounds
* most excreted via kidneys in various degrees as unchanged drug
29
Beta-lactams
All cephalosporins
**When to avoid, caution, pregnancy/lactation, peds**
Avoid: hypersensitivity reaction
Caution: history of anaphylaxis or hypersensitivity reaction with PCN allergy; renal and hepatic impairment
Pregnancy/lactation: compatible
Peds: approved
Ceftriaxone avoided in neonates (esp preterm) as it can displace bilibrubin from albumin binding sites
30
Beta-lactams
All cephalosporins
Monitoring
* c. Diff
* Renal function if prolonged
31
Beta-lactams
All cephalosporins
Adverse fx (11)
* Nausea/Vomiting/Diarrhea
* blood dyscrasias
* maculopapular rash
* Arthralgia
* Fever
* Seizures
* Renal/hepatic failure
* c.diff
* hypersensitivity reaction (Rare)
* hemolytic anemia (rare)
* pain at injection site
32
Beta-lactams
2nd generation: cefuroxime, cefprozil, cefaclor
Indications, target organisms
* indications: cellulitis, COPD acute exacerbation, acute otitis media, GABHS, lyme disease, uncomplicated UTI
* gram positive cocci, methicillin-sensitive s. aureus, s. epidermis, streptococci, e. coli; increased activity against h. influenzae
33
Beta-lactams
3rd generation: ceftriaxone, cefdinir, cefpodoxime, ceftazadin
Indications, target organisms
* Indications:
* Ceftriaxone: bacterial meningitis, CAP, uncomplicated gonorrhea, PID, complicated UTI (male patient, pregnant patient, upper urinary tract infection)
* Cefpodoxime: bacterial bronchitis, CAP, acute bacterial rhinosinusitis, GABHS
* Cefdinir: COPD exacerbation, acute otitis media, strep pharyngitis
* Target organisms: gram positive cocci, methicillin-sensitive s. aureus, s. pneumoniae, n. gonorrhoeae, h. flu, n. meningitidis, e. coli
34
Beta-lactams
4th generation: Cefepime & 5th genderation: Cetaroline
Indications and Target organisms
* 4th gen
* Severe infections, given IV
* Gram positive bacteria
* 5th gen
* IV only, more severe infections
* Active against MRSA
35
Fluoroquinolones
Ciprofloxacin, levofloxacin
Indications & target organisms
* Indications:
* Cipro: , traveler's diarrhea, anthrax
* Levo: COPD exacerbation, h. pylori eradication, CAP, acute bacterial rhinosinusitis, anthrax
* Both: Pyelonephritis, chronic bacterial prostatitis, skin infections, bone/joint infections, complicated intraabdominal
* broad spectrum with esp good coverage for gram negative bacteria, including e.coli, h. flu, m. catarrhalis, p. aeruginosa, s. pneumonia, mycoplasma
36
Fluoroquinolones
Ciprofloxacin, levofloxacin
MOA
bactericidal through interference with enzymes required for synthesis and repair of bacterial DNA and promote breakage of DNA strands
37
Fluoroquinolones
Ciprofloxacin, levofloxacin
Other considerations
* Can no longer be used for gonorrhea, resistant TB
* Well absorbed; take on empty stomach for best absorption.
38
Fluoroquinolones
Ciprofloxacin, levofloxacin
Avoid, caution, other considerations, pregnancy/lactation, peds
* Avoid: myasthenia gravis
* Caution: renal and hepatic impairment, elderly patients
* Other considerations: risk of QT prolongation
* Pregnancy/lactation: avoid
* Peds: 18+
* May use under 18 for pyelonephritis, anthrax, allergies to other meds
39
Fluoroquinolones
Ciprofloxacin, levofloxacin
Black box warning
* BBW: risk of tendon rupture and tendinitis
* Older adults at higher risk
* Can have delayed onset - days to months after administration
40
Fluoroquinolones
Ciprofloxacin, levofloxacin
Patient education
* avoid alcohol use
* Food delays absorption
* Take with full glass of water
* Notify provider if tendon tenderness
41
Fluoroquinolones
Ciprofloxacin, levofloxacin
Adverse fx (11, 4 rare)
* GI fx: Nausea/vomiting/diarrhea, psuedomembranous colitis
* CNS fx: Sleep disorders, dizziness, headache
* CV fx: angina, atrial flutter, increased risk of aortic aneurysm or dissection
* Other: Acidosis, renal/hepatic failure, phototoxicity
* Rare: hypersensitivity reactions, tendinitis, tendon rupture, c. diff
42
Lincosamides
Clindamycin (Cleocin)
Indications & target organisms
* Indications
* MRSA skin infection
* strep pharyngitis
* PID
* first line therapy in peds/pregnancy
* Infections in PCN-allergic patients
* Drug-resistant strep pneumoniae
* Dental infections
* Target organisms gram positive organisms, including s. pneumoniae, s. pyogenes, MRSA, p. acnes, select anaerobic pathogens
43
Lincosamides
Clindamycin (Cleocin)
MOA - bacteriostatic or bactericidal
bacteriostatic; bind to 50s subunit of bacterial ribosome, suppressing protein synthesis
44
Lincosamides
Clindamycin (Cleocin)
Pharmacokinetics, considerations for administration & monitoring
* Pharmacokinetics: Oral dosing completely absorbed as it is not affected by gastric acid
* Other considerations: Take with food and a full glass of water, sit or stand for 30 min after admin to decrease risk of esophageal irritation
* Monitoring: Stop if significant diarrhea occurs and do not start loperamide
45
Lincosamides
Clindamycin (Cleocin)
Black box warning, caution, pregnancy/lactation, peds
* BBW: colitis, c. diff
* Caution: history of GI disease, hepatic impairment
* Pregnancy: compatible, lactation: caution
* Peds: approved, but others preferred
46
Lincosamides
Clindamycin (Cleocin)
Adverse fx (8, 3 rare)
* GI: N/V, abd pain
* Skin: maculopapular rash, burning, itching, erythema
* Dizziness
* Blood dyscrasias (Transient eosinophilia, neutropenia, thrombocytopenia)
* Rare: hypersensitivity reaction, anaphylaxis, agranulocytosis
47
Macrolides and Azalides
Azithromycin, erythromycin, clarithromycin (ACE)
Indications & Target organisms
* indications:
* Azithromycin: h. flu, m. catarrhalis, pertussis, COPD exacerbation, chlamydia (in combo with ceftriaxone to treat gonorrhea at the same time)
* Erythromycin: ophthalmic preparation for bacterial conjunctivitis, acne
* Clarithromycin: COPD exacerbation, H. pylori, pertussis
* Target organisms: broad spectrum gram positive and negative - commonly resistant to beta-lactam abx, including s. pneumoniae, MSSA, h. flu, Bordetella pertussis, mycoplasma, chlamydia, m. catarrhalis, h. pylori
48
Macrolides and Azalides
Azithromycin, erythromycin, clarithromycin (ACE)
MOA
bind to 50s subunit of the bacterial ribosome and inhibit RNA-dependent protein synthesis
49
Macrolides and Azalides
Azithromycin, erythromycin, clarithromycin (ACE)
Pharmacokinetics, pharmacodynamics
* Pharmacodynamics
* Weak bases, activity increases in alkaline media
* Atypical and intracellular organisms commonly resistant to beta-lactam antibiotics are often susceptible
* Cross-resistance seen in all classes
* Pharmacokinetics
* well absorbed from duodenum
* Potent inhibitors of cytochrome 3A4 (CYP3A4)
* Combination with statins may increase risk for myopathy
* Exhibit enterohepatic recycling, which can lead to buildup in the system and can cause n/v; tissue levels are higher than serum levels
50
Macrolides and Azalides
Azithromycin, erythromycin, clarithromycin (ACE)
Avoid, caution, other considerations, pregnancy/lactation, preds
* Avoid: pts at risk for torsades de pointes (azithromycin)
* Caution: renal and hepatic impairment
* Other considerations: risk for QT prolongation (azithromycin)
* Pregnancy/lactation: compatible (clarithromycin not compatible in pregnancy)
* Peds: approved - 6 months + for clarithromycin & azithromycin
51
Macrolides and Azalides
Azithromycin, erythromycin, clarithromycin (ACE)
Interactions & monitoring
* Interactions
* Erythromycin & clarithromycin are potent inhibitors of the P450 system
* Inhibitors of the CYP3A4
* Monitoring
* Hepatic/renal impairment
* Hearing loss
52
Macrolides and Azalides
Azithromycin, erythromycin, clarithromycin (ACE)
Adverse fx (7, 2 rare)
Which is associated with the most GI distress?
* GI fx: N/V/D, abdominal pain
* Skin: skin rash, bullous eruptions, eczema
* Stevens-Johnson syndrome
* hearing loss
* Rare: liver abnormalities, hypersensitivity reactions
* Erythromycin associated with the most GI distress
53
Fidaxomicin (dificid)
Indication, considerations, interactions
* Indication: c.diff infections
* Considerations:
* safe in pregnancy
* 18+
* Interactions: Rifampin, rifamixin
54
Oxazolidinones: Linezolid
* Indications:MRSA pneumonia, uncomplicated skin infections
* Target organisms: Gram-positive bacteria
* MOA: inhibits bacterial ribosomal protein synthesis
* Considerations
* Expensive, resistance is emerging
* Pharmacokinetics: Well absorbed orally, does not use CYP450 enzymes
55
Sulfonamides & Trimethoprim: Sulfamethoxazole/trimethroprim (Bactrim)
Indications & Target organisms
* UTI, including suppression, MRSA, PCP pneumonia
* gram positive and gram negative, including e.coli, toxoplasma gondil, pneumocystitis jirovecii (PCP pneumonia)
56
Sulfonamides & Trimethoprim: Sulfamethoxazole/trimethroprim (Bactrim)
MOA of each
* Sulfonamides block folic acid synthesis
* trimethoprim inhibits DNA synthesis
* nitrofurantoin may inhibit acetyl coenzymes
57
Sulfonamides & Trimethoprim: Sulfamethoxazole/trimethroprim (Bactrim)
Avoid, caution, pregnancy/lactation, peds, monitoring
* Avoid: sulfa allergy, G6PD deficiency
* Caution: folate deficiency, renal impairment
* Pregnancy/lactation: alternative agents should be used
* Peds: 2months+
* Monitoring
* CBC for long-term use
* Chest x-ray for those on nitrofurantoin that develop a cough
58
Sulfonamides & Trimethoprim: Sulfamethoxazole/trimethroprim (Bactrim)
Adverse fx (8, 6 rare)
* GI: N/V/D, abd pain, stomatitis, anorexia
* CNS: headache, dizziness, photosensitivity
* Hyperkalemia
* Rare: crystalluria, hypersensitivity reactions, hemolytic anemia, kernicterus (bilirubin-associated brain damage), Steven-Johnson syndrome, agranulocytosis
59
Tetracyclines: Doxycycline, tetracycline
Indications & target organisms
* chlamydia, gonorrhea, lyme disease, CAP, COPD exacerbation, H. pylori eradication, Rocky mountain spotted fever
* broad spectrum with good coverage against gram positive & negative including s. aureus, s. pneumoniae, p. acnes, h. flu, chlamydia, mycoplasma pneumoniae, rickettsia, t. pallidum, h. pylori
60
Tetracyclines: Doxycycline, tetracycline
MOA & patient education
* inhibit protein synthesis by reversibly binding to 30s subunit of the bacterial ribosome
* Patient education:
* photosensitivity
* need back up birth control method for tetracycline
* best with food but not with dairy
* take with a full glass of water and standing 30 minutes upright after admin to decrease esophageal irritation
61
Tetracyclines: Doxycycline, tetracycline
Caution, pregnancy/lactation, peds
* Caution: renal & hepatic impairment
* Pregnancy: avoid; lactation: short term use only
* Peds: avoid younger than 8 except for if treating rocky mountain spotted fever
62
Tetracyclines: Doxycycline, tetracycline
Adverse fx (6, 2 rare)
* GI: N/V/D, anorexia
* CNS: Lightheadedness, dizziness, photosensitivity
* Hypertension
* Rare: c. diff, severe skin reactions
63
Glycopeptides: Vancomycin, telavancin (Vibativ), dalbavancin (Zeven)
Indications, target organisms
* Indications
* MRSA resistant to first-line abx
* Oral vanco: c.diff
* Target organisms: severe gram positive organisms, including c. diff and s. enterocolitis; bactericidal
64
Glycopeptides: Vancomycin, telavancin (Vibativ), dalbavancin (Zeven)
MOA, how is it usually administered?
* inhibit bacterial cell wall synthesis by blocking glycopeptide polymerization through binding tightly to the D-A1a-D-A1a portion of the cell wall precursor
* Admin
* Poorly absorbed orally - usually given IV
* Oral for c.diff
65
Glycopeptides: Vancomycin, telavancin (Vibativ), dalbavancin (Zeven)
Pregnancy/lactation, peds, monitoring
* Pregnancy/lactation: compatible
* Peds: approved
* Monitoring: hearing, renal function
66
Glycopeptides: Vancomycin, telavancin (Vibativ), dalbavancin (Zeven)
Adverse fx (10)
* GI: nausea, bitter taste, mouth irritation, abd pain
* CNS: fatigue, HA
* peripheral edema
* Red man syndrome if administered too fast
* Ototoxicity
* Nephrotoxicity
67
Nitrofurantoin
Indication & Target organisms
* uncomplicated UTIs including long-term suppression UTIs
* gram positive and gram negative bacilli that cause UTIs; most often caused by e.coli
68
Nitrofurantoin
MOA
activated by bacteria to reactive intermediates that inactivate or alter bacterial ribosomes, leading to inhibition of protein synthesis, aerobic energy metabolism, DNA, RNA, cell wall synthesis; may inhibit acetyl coenzymes
69
Nitrofurantoin
Avoid, caution, pregnancy/lactation, peds
* Avoid: CrCl less than 30, G6PD
* Caution: CrCl less than 60
* Pregnancy: avoid at term (38-42 weeks); lactation: avoid when infant is less than one month old
* Peds: 1month+
70
Nitrofurantoin
Adverse fx (4, 5 rare)
* HA
* Nausea
* Rash
* urine discoloration
* Rare: hepatic dysfunction, agranulocytosis, hemolytic anemia, peripheral neuropathy, hypersensitivity reaction
71
Nucleoside analgogues
Acyclovir, famciclovir, valacyclovir
Indications
* Acyclovir: herpes simplex, genital herpes, herpes zoster, varicella, gingivostomatitis, CMV
* Famciclovir: herpes simplex, oral and genital herpes; herpes zoster, epstein-barr, hep B
* Valacylovir: herpes - genital, oral & zoster, varicella, gingivostomatitis (converted to acyclovir after oral admin - active against same viruses)
* Ganciclovir: CMV
* Herpes simplex: if greater than 6 occurrences per year, suppressive therapy should be considered; treat within 72 hours of an outbreak; decrease pain, duration of viral shedding and time to complete resolution
72
Nucleoside analgogues
Acyclovir, famciclovir, valacyclovir
MOA, prescribing considerations
* interfere with DNA synthesis and inhibit viral replication
* Acyclovir: frequent dosing but not expensive
* Valacyclovir: favored over acyclovir due to less frequent dosing
73
Nucleoside analogues
Acyclovir, famciclovir, valacyclovir
Caution, pregnancy, peds, monitoring
* Caution: renal impairment
* Pregnancy/lactation: acyclovir recommended
* Peds: acyclovir for 2+
* Monitoring: BUN and creatinine may be assessed before therapy in those who have risk factors for renal impairment
74
Nucleoside analogues
Acyclovir, famciclovir, valacyclovir
Adverse fx (7, 1 rare; 2 for valacyclovir; 3 for ganciclovir)
* GI: N/V, nasopharyngitis
* CNS: HA, fatigue, depression
* skin rash
* elevated transaminases
* Rare: crystalluria
* Valacyclovir: thrombocytopenia purpura, hemolytic uremic syndrome in immunocompromised patients
* Ganciclovir: granulocytopenia, anemia, thrombocytopenia
75
Antivirals for Hep C
Ledipasvir/sofosbuvir, sofosbuvir/velpatasvir
How is treatment determined? MOA
* Treatment based on genotype and stage of disease - therapy usually started by a hepatologist, lasts approximately 12 weeks
* inhibit HCV protein necessary for viral replication
76
Antivirals for Hep C
Ledipasvir/sofosbuvir, sofosbuvir/velpatasvir
Black box warning, pregnancy/lactation
* BBW for hep B virus reactivation - test for Hep B prior to starting therapy, hold therapy if need Hep B treatment first
* Pregnancy: avoid; lactation: limited data
77
Antivirals for Hep C
Ledipasvir/sofosbuvir, sofosbuvir/velpatasvir
Interactions, monitoring
* Interactions: co-administration of ledipasvir and sofosbuvir (Harvoni) and amiodarone may cause serious symptomatic bradycardia
* Monitoring
* Bilirubin
* Liver enzymes
* Serum creatinine
78
Antivirals for Hep C
Ledipasvir/sofosbuvir, sofosbuvir/velpatasvir
Adverse fx (5)
* GI: N/D
* CNS: HA, fatigue
* Myalgias
* Pruritis
79
Antivirals for influenza
Neuraminidase inhibitors: oseltamivir, zanamivir, peramivir
Indications & MOA
* Oseltamivir, zanamivir: Prophylaxis and treatment Influenza A & B
* Peramivir: acute influenza 18
* MOA: neuraminidase is a viral enzyme responsible for cleaving viral attachment to the host cell surface, allowing for viral circulation; inhibiting this enzyme prevents release of virus and halts the spreading of infection
80
Antivirals for influenza
Neuraminidase inhibitors: oseltamivir, zanamivir, peramivir
Prescribing considerations
* Start oseltamivir within 48 hours of sx onset, treatment up to 5 days after onset may reduce morbidity and mortality in hospitalized patients
* Oseltamivir: well absorbed after oral administration.
* Zanamivir: inhaled; 4% to 17% is absorbed.
* Peramivir: administered intravenously (IV).
81
Antivirals for influenza
Neuraminidase inhibitors: oseltamivir, zanamivir, peramivir
Avoid, caution, pregnancy/lactation, peds
* Avoid: zanamivir with hx of respiratory disease
* Caution: renal & hepatic impairment
* Pregnancy: caution; oseltamivir ok in lactation
* Peds: each has an approved age
82
Antivirals for influenza
Neuraminidase inhibitors: oseltamivir, zanamivir, peramivir
Monitoring
* Renal function in older and debilitated patients
* Older: confusion, hallucinations, cognitive impairment
83
Antivirals for influenza
Neuraminidase inhibitors: oseltamivir, zanamivir, peramivir
Adverse fx (2, 2 rare; 3 for zanamivir)
* HA
* N/V
* Rare: anaphylaxis, neuropsychiatric events
* Zanamivir: bronchitis, cough, SOB
84
Antivirals for influenza
Baloxavir marboxil
Indications, MOA
* influenza A & B
* dependent endonuclease inhibitor that interferes with viral RNA transcription, resulting in inhibition of influenza virus replication
85
Antivirals for influenza
Baloxavir marboxil
Pregnancy/lactation, peds, other considerations; adverse fx
* Pregnancy/lactation: other agents recommended
* Peds: 12+
* Other considerations: administered as a single dose due to long half-life, more expensive
* Adverse fx: Diarrhea, nasopharyngitis
86
Systemic Azoles
Fluconazole, Itraconazole, Terbinafine
Indications for each
* Fluconazole: candidiasis - vaginal, oropharyngeal, esophageal
* Itraconazole: onychomycosis; off-label use for extensive tinea infections
* Terbinafine: 1st line systemic treatment for onychomycosis; off-label use for extensive tinea infections
87
Systemic Azoles
Fluconazole, Itraconazole, Terbinafine
MOA
* Fluconazole & Itraconazole: interferes with fungal cytochrome P450 activity, decreasing ergosterol synthesis and inhibiting cell membrane formation
* Terbinafine: synthetic allylamine derivative that inhibits squalene epoxidase, a key enzyme in sterol biosynthesis in fungi; results in fungal cell death
88
Systemic Azoles
Fluconazole, Itraconazole, Terbinafine
Prescribing considerations
* Fluconazole
* inhibitor of cytochrome 3A4 (CYP3A4) and CYP2C9
* Requires loading dose
* Itraconazole: Absorption enhanced by food
* Terbinafine: metabolized by CYP450 system
89
Systemic Azoles
Fluconazole, Itraconazole, Terbinafine
What is there a risk for in all of these medications?
Caution, pregnancy/lactation, peds, black box warning
* Risk for QT prolongation
* Caution: arrythmias, renal & hepatic impairment
* Pregnancy: avoid
* Fluconazole - lactation: caution
* Itraconazole & Terbinafine - lactation: avoid
* Peds: approved
* Itraconazole: limited data for peds
* Itraconazole BBW: avoid in patients with HF; AHA has recommended not using in patients with underlying myocardial dysfunction
90
Systemic Azoles
Fluconazole, Itraconazole, Terbinafine
Patient education, drug interactions & monitoring for Fluconazole
* Patient education
* Take with food
* No alcohol
* Signs of liver toxicity
* Interactions: Drugs metabolized by CYP450
* Monitoring for Fluconazole:
* aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and bilirubin before starting and every 3 to 4 months
91
Systemic Azoles
Fluconazole, Itraconazole, Terbinafine
Adverse fx of each
* All: headache, nausea, vomiting, diarrhea
* Rare: hepatotoxicity
* Fluconazole: dizziness
* Rare: anaphylaxis, skin reactions
* Itraconazole: skin rash, edema
* Rare: skin reactions, CNS depression, hearing loss
* Terbinafine: depression, taste disturbance
* Rare: hepatic failure, skin reactions, ocular effects, blood dyscrasias
92
Metronidazole (Flagyl)
Indications & Target organisms
* c.diff (after tried vanco), bacterial vaginosis, h. pylori eradication, trichomoniasis, PID
* Oral or topical (trichomoniasis, bacterial vaginosis)
* gram positive and gram negative anaerobes including C. diff, bacteroides fragilis, h. pylori, t. vaginalis, garnerella vaginallis, g. lamblia, e. hystolica
93
Metronidazole (Flagyl)
MOA
diffuses into organism and interacts with DNA to cause of loss of helical DNA structure and strand breakage, resulting in inhibition of protein synthesis and cell death
94
Metronidazole (Flagyl)
Caution, pregnancy/lactation, peds, black box warning
* Caution: renal and hepatic impairment, seizure disorder
* Pregnancy: caution; lactation: avoid
* Peds: approved
* BBW: potentially carcinogenic
95
Metronidazole (Flagyl)
Patient education
* Avoid alcohol during treatment and 2 days post treatment to avoid disulfiram reactions
* If treating for trichomoniasis or bacterial vaginosis: abstain from sexual intercourse
96
What are symptoms of a disulfram reaction?
nausea, vomiting, flushing, dizziness, throbbing headache, chest and abdominal discomfort
97
Metronidazole (Flagyl)
Adverse fx (8, 4 rare)
* GI: Nausea, abdominal pain, anorexia, metallic taste, dry mouth, dark urine
* CNS: Dizziness, HA
* Rare: agranulocytosis, CNS effects, superinfections, hepatotoxicity
98
Tinidazole
Indications & target organisms
* bacterial vaginosis, h. pylori eradication (off-label), trichomoniasis, urethritis
* bacteroides fragilis, h. pylori, t. vaginalis, gardnerella vaginalis, giardiasis, trichomoniasis, amebiasis
99
Tinidazole
MOA
diffuses into organism and causes cytotoxicity by damaging DNA and preventing additional DNA synthesis
100
Tinidazole
Caution, pregnancy/lactation, peds, black box warning
* Caution: hepatic impairment
* Pregnancy/lactation: avoid
* Peds: 3+
* BBW: potentially carcinogenic
101
Tinidazole
Patient education
* administer with food
* avoid alcohol
* abstain from sexual intercourse for VB and trichomoniasis
102
Tinidazole
Adverse fx (4, 3 rare)
* GI: nausea, anorexia, metallic taste
* Fatigue
* Rare: seizures, peripheral neuropathy, superinfection (c. diff, vaginal candidiasis)
103
Why is there cross-sensitivity between PCN and cephalosporins? What medications are safer to use if the patient has a PCN allergy?
* Cross-sensitivity between PCN and cephalosporins due to shared side chain - less than or equal to 1%
* 1st and some 2nd gen have similar side chains to PCN
* Safer if patient has PCN allergy: cefprozil, cefuroxime, cefpodoxime, ceftazidime, ceftriaxone
104
Which drugs are no longer recommended for use to treat influenza due to resistance?
amantadine and rimantadine
105
What medications are used for more serious cases of impetigo?
* 5+ lesions or if no improvement within 2-3 days: cephalexin (keflex), amoxicillin/claulanate, dicloxacillin
106
Which topical can be used for onychomycosis?
ciclopirox (penlac)
