Macrolides exam 1 drug list

Question 1

Name 3 Macrolides:

Answer 1

Azithromycin
Erythromycin
Clarithromycin

Question 2

Are macrolides Bactericidal or bacteriostatic?

Answer 2

Bacteriostatic

Question 3

Prototype drug

Answer 3

Erythromycin

Question 4

Azithromycin is derived from

Answer 4

Erythromycin

Question 5

Due to drug interactions and side effects of Erythromycin and clarithromycin

Answer 5

Azithromycin is preferred and is the majority of macrolide use

Question 6

Macrolides exhibit

Answer 6

Immunomodulating properties (useful in infectious diseases and cystic fibrosis)

Question 7

Macrolide MOA

Answer 7

reversibly binds to the P site of the 50S ribosomal subunit of susceptible organisms and may inhibit RNA-dependent protein synthesis by stimulating the dissociation of peptidyl-tRNA from ribosomes.

Question 8

Azithromycin Indications

Answer 8

Chronic bronchitis, sinusitis, CAP, Pharyngitis, and tonsillitis

Uncomplicated skin soft tissue infections

Chlamydia trachomatis and gonorrhea

Travelers diarrhea

Question 9

Erythromycin Indications

Answer 9

CAP, bronchitis, pertussis

Impetigo cellulitis

Neonatal conjunctivitis caused by (N. gonorrhoeae or chlamydia trachomatis)

Chlamydia

Prophylaxis for rheumatic fever in those with penicillin allergies

Bacterial endocarditis for dental or surgical procedures

Question 10

Clarithromycin Indications

Answer 10

CAP, bronchitis, sinusitis, pharyngitis

H. pylori eradication

acute otitis media

Dental procedures (endocarditis)

Question 11

Macrolides absorption

Answer 11

Well-absorbed from the duodenum with oral administration

Minimal absorption from topical or ophthalmic use

Question 12

Macrolide Distribution

Answer 12

Readily to body tissues

Enters pleural fluid, ascitic fluid, middle ear exudates, and sputum.

Meninges if they are inflamed

Enter CSF

Question 13

Macrolide Metabolism

Answer 13

partially by the liver

Question 14

Macrolide excretion

Answer 14

mainly unchanged in the bile, also unchanged in the urine

Question 15

Both Erythromycin and Clarithromycin have a higher number of
drug interaction due to? What medication should be stopped if taking either abx?

Answer 15

being strong inhibitors of the CYP enzymes (CYP3A4)

HMG-CoA Reductase Inhibitors (Statins) should be stopped while on
either due to risk of severe myopathy or rhabdomyolysis

Question 16

Erythromycin is heavily metabolized by

Answer 16

CYP3A4 which explains its many drug interactions

Question 17

Erythromycin contraindicated in patients with?

Answer 17

Preexisting liver disease

Question 18

Due to Azithromycin’s being excreted via the liver?

Answer 18

Patients with hepatic dysfunction require cautious use of the drug

Question 19

What EKG change has been observed?

Answer 19

QT interval

Question 20

Macrolide ADRs

Answer 20

Dose-related GI symptoms, including nausea, vomiting, abdominal pain, cramping, and diarrhea.

Question 21

Azithromycin and erythromycin ADRs

Answer 21

Associated with liver abnormalities, including hepatitis, cholestatic jaundice, and hepatic failure.

Question 22

What’s the major reason selecting azithromycin over other macrolides?

Answer 22

Enhanced compliance due to convenient once a day dosing for 3 to 5 days, missing one day could cause unsuccessful treatment.

Question 23

Macrolide Resistance

Answer 23

(1) reduced permeability of the cell membrane or active efflux,
(2) modification of the ribosomal binding site by chromosomal mutation, or
(3) production of esterase by Enterobacterales that hydrolyze macrolides.

Question 24

Clindamycin MOA

Answer 24

Binds to 50S subunit of bacterial ribosome; Suppresses protein synthesis

Question 25

Clindamycin indications

Answer 25

Limited due to potential for severe diarrhea/C-Diff, resistance, and better tolerated alternatives

Question 26

Clindamycin active against

Answer 26

Gram positive bacteria anaerobic pathogens

Question 27

Clindamycin significant role in

Answer 27

Secondary infections due to staphylococcal/streptococcal species in penicillin-allergic patients

Question 28

Clindamycin impact on septic shock?

Answer 28

Inhibition of protein synthesis, can decrease toxin production

Question 29

Clindamycin resistant considerations

Answer 29

Ribosomal receptor site mutation/modification Enzymatic inactivation

Question 30

Clindamycin Absorption/Distribution

Answer 30

PO: Complete absorption, not affected by gastric acid or food Distributes to pleural/peritoneal fluids w/high conc in bile/bone Poor CSF penetration Highly protein bound Crosses placenta and found in breast milk

Question 31

Clindamycin Metabolism/Excretion

Answer 31

Metabolism in liver Excreted in bile/urine(10%) No dosage modification unless severe renal/hepatic impairment

Question 32

Clindamycin use in infants and children

Answer 32

Reserved for serious infections, When less toxic alternatives are inappropriate

Question 33

Clindamycin ADRs

Answer 33

GI: N/V, Bitter metallic taste, Dizziness, Vertigo, H/a, hypotension, rare cardiac arrhythmias, Indications of hepatic dysfunction Risk for C-Diff very high

Question 34

Drug interactions

Answer 34

Erythromycin: Antagonist effects Kaolin-pectin: Delays GI absorption NMB: Severe respiratory depression

Question 35

Clindamycin clinical use

Answer 35

Bacterial Endocarditis prophy as alternative for penicillin allergic pt Pneumococcal pneumonia, skin/tissue infections as penicillin alternative Drug-Resistant Penumococcal Infections