Module 11 part 1 Quiz

Question 1

Bactericidal

Answer 1

Disrupt cell wall–>lysis

Classes:
1 penicillins
2. Cephalosporins
3. Individual (Vancomycin)

Question 2

Penicillins

Answer 2

Beta Lactams, contain beta lactam ring
narrow or broad=treat a wide variety

Low toxicity but common cause of allergies
-can be life threatening
-avoid in patients with allergy history

Action: Disruption of cell wall by targeting PCN binding proteins (PCB)–> bacterial water uptake–> rupture, bactericidal

Beta lactamases promote resistance to PCN

Methicillin is resistant to beta lactamases

Question 3

Methicillin Resistant Staph Aureus

Answer 3

MRSA: gram +
colonizes in nares, and skin of health people
-Infection: soft tissues, abscess, boils cellulitis
Mortality 30-40%
Developed resistance over time
resistant to methicillin, all PCNs, and most cephalosporins

Health care environment and community

Question 4

Cephalosporins

Answer 4

Beta-Lactam
Broad spectrum
Low toxicity
Action: bind to PCN binding proteins–>dissruption of cell wall synthesis, activation of autolysis

Admin: poor GI absoprtion, IV or IM

Five generations of drugs
-increase activity against gram negative rods and anerobes
-increase resistance to B-lactamases
-increase CSF penetration

Question 5

Vancomycin

Answer 5

Indication: MRSA, serious infections, C-diff (PO), gram + only, allergy to PCN

Action: inhibits cell wall synthesis–> lysis, No beta Lactam ring

Admin: IV or IM, except for cdiff (PO)

AEs: Nephrotoxicity-dose related, increase with concurrent use of other nephrotoxins, monitor serum trough levels to avoid toxicity

Question 6

Bacteriostatic Drugs

Answer 6

-Suppress bacterial growth/replication

-Do not eradicate or kill

-2nd line agent

-Inhibit bacterial protein synthesis

E.g. Tetracyclines, Macrolides

Question 7

Tetracyclines

Answer 7

Broad spectrum abx: gram + and gram -
Prototype: Doxycycline
Action: inhibit protein synthesis affecting RNA

Extensive use=increasing resistance
-first line use limited
-Used for: lyme disease, chlorea, anthrax, typhus, Q fever, topical for acne

Notes: Food/ Ca+ products decrease absorption through GI, Can cause GI upset (take w/ small meal), monitor for superinfection, Contraindicated for this with renal failure

Question 8

Macrolides

Answer 8

Broad spectrum
-Most gram +, some gram -
Prototype: Erythromycin
Action: Inhibit protein synthesis. Usually bacteriostatic
Indications: diptheria, as a subisitute for penicillin G, chlamydia

Notes: one of the safest, Small risk for QT prolongation, when combined with CYP inhibitor= 5x risk for death

AVOID IN THOSE W/ QT PROLONGATION/CYP INHIBITORS AND CLASS 1A OR III ANTIDYSRYTHMICS

Question 9

2nd most common infection, affects women> men

Answer 9

UTI

Question 10

Lower UTI

Answer 10

Cystitis and urethritits

Question 11

Upper UTI

Answer 11

Pylenephritits

Question 12

Complicated UTIs

Answer 12

BPH, indwelling foley, calculi, obstruction

Question 13

Exception to treatment of UTI w. PO abx

Answer 13

Severe pyelonephritis

Question 14

Acute cystitis

Answer 14

Lower UTI
Affects women of child bearing age

Sx/symp: dysuria, frequency, suprapubic discomfort, pyuria, bacteriuria

Tx options:
1. Short course (preferred 3 days)
2. Single dose
3. Conventional (7 days)

Question 15

Urinary tract antiseptics

Answer 15

Prototype: Nitrofuratoin
Broad spectrum: active against common urinary pathogens, indicated for acute lower UTI and proph

Actions: concentrations in the urine and damage DNA, bacteriostatic at low concentrations, bacteriocical at high
Caution: proteus, psedomonas, enterobactar, klebsiella 2ndry to high rates of resistance

SEs: GI (minimized w/ taking with meals/milk), hypersensitivity reactions, irreversible neuropathy

Question 16

Trimethprim/Sulfamethoxazole

Answer 16

Brand name: Bactrim. fixed dose combination
-Class: sulfonamide combo
Actions: Broad spectrum: sulfa is bacteriostatic and inhibits bacterial synthesis of DNA/RNA, concentrates in urine, trimeth may be bactericidal or static

Infection: UTI, ottitis media, bronchitis

Drug-drug: CYP inhibitor, increase effects of warfarin/glyburide and others

Question 17

Adverse reactions of sulfa abx

Answer 17

Hypersensitivity- mild: rash, fever, photosensitvity

Severe: steven johnson syndrom, blood dyscrasias

Question 18

Stevens-Johnson Syndrome

Answer 18

Rare, 25% mortality rate
-associated with long/short acting sulfonamides

Sx/Symp: lesions of skin and mucous membraine, fever, malaise, toxemia

Discontinue sulfa drugs if ANY rash develops

Question 19

Aminoglycosides

Answer 19

Prototype: Gentamtycin

Spectrum: Narrow
indications: serious infections r/t aerobic gram - bacilli (E.coli, Proteus, etc)

Action: Bacteriocidal by interupting bacterial protein synthesis
Admin: not absorpbed from GI. Given IM, IV, topical
AEs: ototoxicity, nephrotoxicity

Post abx effect: drug remins bacteriocidal several hours after levels fall below the minimum bacteriocical concentration

Question 20

Fluoroquinolones

Answer 20

Prototype: Ciprofloxacin
Spectrum: broad against most gram + and gram - bacteria. can treat most UTI related pathogens (E. coli, klebsiella)

Applications: multiple
Action: Disrupt DNA replication and cell division
Admin: IV or oral

SE: mild: N/V, headache, candida

Question 21

Ciprofloxacin

Answer 21

Broad spectrum: Gram + and gram -
Action: Inhibits bacterial enzymes required for replication/division

Uses: respiratory infections, bones/joints, skin and soft tissues, UTIs, Enteritits, not great for anerobes

Drug-Drug: absorption decreased by cation containing compounds (antacids/dairy), increase warfarin/theophylline

Question 22

Ciprofloxacin adverse reactions

Answer 22

Tendonitis & tendon rupture, usually achilles
-in older adults can=confusion, somnolence, psychosis, phototoxicity
-Worsens MG

Question 23

Metronidazole/Flagyl

Answer 23

Spectrum: Anerobes/protozoans
Class: nitromidazole
Action: taken up by anerobes and converted=damage to helix
Uses: C. diff, bacterioides, H. pylori, proph in surgical procedures
Drug-Drug: absorption decreased with cation containing compounds (antacids/dairy), increase warfarin/therophylline

Question 24

TB treatment goals

Answer 24

1. eliminate infection
2. Prevent relapse
3. prevent drug resistance

Question 25

TB drug resistance

Answer 25

Multi drug resistant TB and extensively drug resistant TB -resistant to isoniazid and rifampin -XDR TB-also resistant to fluoquroquinolones and a 2nd line agent Implications: increase risk of death -$$$$ standard TB cost 18 K compared to 700 K

Question 26

What causes TB drug resistance

Answer 26

-too short a course -doses too low -erratic adherence -too few drugs

Question 27

To help prevent TB drug resistance

Answer 27

-MUST ALWAYS TREAT WITH 2 OR MORE DRUGS

Question 28

TB drug selection

Answer 28

-sensitivity to organism -immunocpmpetence of host -first line: rifampin, isoniazid, ethambutol, pyranzinamide

Question 29

phased therapy

Answer 29

1. Elimination of dividing bacilli render sputum non infectious, may take up to 8 weeks, four drug combo 2. Continuation phase -elimination of persistent organisims -may take up to 18 weeks -two drug combo: isoniazid and rifampin

Question 30

Clinical pears of TB treatment

Answer 30

therapy initiated with four drug combo -if resistance = + more drugs (up to 7) -Tx of MDR TB: 2 years of meds -may require surgery tp excise infected tissue -40-60% mortality

Question 31

Adherence for TB treatment

Answer 31

-DOT (directly observed therapy) -intermittent dosing (2-3x week) Evaluation of clinical response: -bacteriological eval of sputum -chest x ray

Question 32

Isoniazid

Answer 32

Indications: treatment and prph of TB Action: bacteriocidal: inhibits synthesis of bacterial cell wall SEs: peripheral neuropathy, heaptotoxicity (increase in advanced age), neuro effects: ataxia/optic neuritis, psychiatric disturbance, pancreatitis Drug-drug: potent inhibitor of CYP (raise levels of many drugs)

Question 33

Patient teaching for Isoniazid

Answer 33

-S/s of hepatits -need monthly eval for these