STI Drugs

Question 1

Azithromycin

Answer 1

Tx: Chlamydia
Macrolide, binds 50S blocks translocation
Static against aerobic Gm+ and some - (Chlamydia)
AE: N+V, diarrhea, anorexia

Question 2

Doxycycline

Answer 2

Tx: Chlamydia
Tetracycline binds 30S, blocks peptide elongation
Static against aerobic Gm+ and some - (Chlamydia)
AE: GI, tooth and growth, photosensitivity, hepatotoxicity in preg.

Question 3

Ceftriaxone

Answer 3

Tx: Gonorrhea
3rd generation cephalosporin, blocks transpeptidase so hurts cell wall
Cidal v Gm+ and - (gonnococcus)
Good in urethral, cervical, rectal and pharyngeal
Often with chlamydial tx
AE: allergy, pain at injection site

Question 4

Metronidazole

Answer 4

Tx: Trichomoniasis
Prodrug activated by PFOR in susceptible microbes
Makes toxic radical, damages DNA
Kills anaerobic and protozoans
AE: common: HA, nausea, dry mouth
rarer: vom, insom, dysuria, diarrhea, vertigo
NO: EtOH, CNS dz, first trimester, lactation

Question 5

Acyclovir, valacyclovir, famicyclovir

Answer 5

Acyclic guanosine analog, activated by viral kinase
inhibits viral DNAP, and chain termination
Reduces shedding, shorten flare, speeds recovery
AE: Well tolerated, rarely: N+V, HA, diarrhea