Macrolides

Question 1

MOA of erythromycin

Answer 1

Binds 50s ribosome
Prevents translocations movement of ribosome
bacteriostatic

hepatic metabolism

Do nOt take azithromycin with food. Slowly eliminating

Question 2

Erythromycin is given against

Answer 2

Campylobacter
Chlamydia
Mycoplasma
Legionella
Positive cocci
Mainly effective on G+ bacteria
A. Gram- positive bacteria
Staph. Aureus
S. pneumoniae
URTIs ( eg. Otitis media,
pharyngitis )
LRTIs ( eg. Pneumoniae )
S. pyogens
C. diphtheria
B. Gram- negative bacteria
T. pallidum
C. Intracellular organisms
L. pneumophila M. pneumoniae C. trachoma
C2ML

Question 3

Azithromycin and clarithromycin

Answer 3

CMT
Chlamydia
Mycobacterium
Toxoplasma

Azithromycin: gonorrhoea wd ceftriaxon, also in H inluenza

Resistance: effluxpump, methylase

Question 4

4-day corse in community acquired pneumonia

Answer 4

Azithromycin
Less dose per day needed
Mainly effective on G- bacteria but less active against G+(s.pneumoniae & s.pyogenes) than erythromycin A. Gram- positive bacteria
Staph. Aureus S. Pneumoniae S. Pyogens
B. Gram- negative bacteria (> erythromycin)
M. catarrhalis
H. influenzae
C. Intracellular organisms (> erythromycin)
L. Pneumophila M. pneumoniae
Chlamydia species

Question 5

For h pylori and prophylaxis against mycobacterium

Answer 5

Clarithromycin
Gram- positive bacteria Staph. Aureus
S. Pneumoniae
S. Pyogens
B. Gram- negative bacteria
H. influenzae H. Pylori
M. catarrhalis
C. Intracellular organisms
M. pneumoniae L. Pneumophila

Question 6

Toxicity of macrolides

Answer 6

Hepatitis in preg
GI irritation
Inhibit P450 enzymes (increase levels)
Thrombophlebitis
Cholestatic hepatitis

Question 7

Telithromycin

Answer 7

Similar to macrolides
Is a ketolide

Binds tightly to ribosomes
Oral
Excreted in bile and urine

Git and hepatic dysfunction
Prolong qt
Inhibit of liver enzymes