Macrolides/erythromycin

Question 1

generalizations of class/Erythromycin

Answer 1

alternative to penicillin allergies
for gram-positives
less GI irritation, some w/enteric coatings
well tolerated and safe
may decrease hepatic metabolism of other drugs
Erythromycin is the prototype

Question 2

therapeutic class

Answer 2

antibacterial

Question 3

pharmacologic class

Answer 3

protein synthesis inhibitor, macrolide

Question 4

pregnancy category

Answer 4

B

Question 5

mechanism of action

Answer 5

inhibits protein synthesis by binding to 50S ribosomal subunit
bacteriostatic but cidal in high doses

Question 6

indications

Answer 6

prophylaxis and treatment of bacterial infections

Question 7

contraindications

Answer 7

hypersensitivity to drugs in class; terfenadine, astemizole or cisapride

Question 8

precautions

Answer 8

impaired hepatic or biliary function

Question 9

drug interactions

Answer 9

drugs that induce or inhibit CYP450
increase serum levels and toxicities of some drugs
increase effects of digoxin or warfarin
not with lobastatin or simvastatin
grapefruit juice increases bioavailability
avoid with fluconazole

Question 10

adverse effects

Answer 10

nausea, vomiting, abdominal cramping, phlebitis and intense pain at IV injection site

Question 11

serious adverse effects

Answer 11

CARDIOTOXICITY WITH RISK FOR TORSADES DE POINTES; cholestatic hepatitis, anaphylaxis, hearing loss, vertigo, dizziness

Question 12

responsibilities

Answer 12

give orals with 8 oz water on empty stomach 1 hr before or 3 hrs after eating; give enteric-coated tablets w/o regard to meals; report adverse effects, ototoxic effects and superinfections; assess intermittent hepatic function tests

Question 13

teaching

Answer 13

monitor for severe diarrhea, abdominal pain or fevers or hearing loss; don’t take w/ fruit juices or carbonated drinks, shake liquid and drops well; some brands ok with meals, no breast feeding