Week 18.2 Drugs

Question 1

Isoniazid

Answer 1

Antymycobacterial-TB
INH--> INH* via KatG---/ InHA
---/ FA elongation (mycolic A synth)
(R.) InHA mutation or KatG mutation
(X) + rifampin- TB 
(X) latent TB- alone for 9mo
(O) slow Nactyltransferase ^ neg SE
(-) neurotoxicity (+ with vit B6)
(-) acetylhydrazine> heptatotoxicity ~ age

Question 2

Rifampin

Answer 2

Antymycobacterial-TB
--/DNA-dep B subunit of RNA polym (intra/extracell) 
(X) TB + isoniazid
(-) hepatotoxicity
(-) orange-red color to secretions
(O) INDUCE CYP

Question 3

Ethambutol

Answer 3

Antymycobacterial-TB
--/arabinosyl transferase--/CW synth (arabinoglycan polym)
(+) CNS distrib BUT STATIC 
(X) DISSEMINATED TB 
(-) optic neuritis

Question 4

Pyrazinamide

Answer 4

Antymycobacterial-TB
--/FA synthatse I (==/mycolic acid synth) 
(X) short-term combo tx 
(+) CNS 
(-) hepatotoxicity (esp + rifampin)

Question 5

Streptomycin

Answer 5

Antymycobacterial-TB
Aminoglycoside (IM admin)
--/30S/50S initiation complex formation (EXTRAcellular)
(X) MOST SERIOUS TB 
(-) ototoxicity, nephrotoxicity (rev)

Question 6

Rifabutin

Answer 6

Atypical Mycobacterial Tx
rifampin analog---/RNA synth
(X) prophylaxis of MAC 
(X) alt of rifampin in multi-drug tx of MAC 
(-) hepatotoxicity, CYP inducer
(less than rifampin)

Question 7

Clarithromycin

Answer 7

Atypical Mycobacterial Tx- Macrolide–/RNA synth
(X) MAC prophylaxis of MD tx
(-) INHIBIT CYP3A4

Question 8

Dapsone

Answer 8

Antymycobacterial-Leprosy
para-aminobenzoic acid analog–/folic acid synthesis (STATIC)
(X) leprosy
(X) prophylaxis /tx of pneumocystis jiroveci
(O) N-Act-T 2 polymorphisms
(-)hemolytic anemia, methemoglobinemia

Question 9

Clofazimine

Answer 9

Antymycobacterial-Leprosy
bind DNA---/repro and growth
(X) combo tx , dapsone-Resistant
(X) lepramatous leprosy 
(-) red-brown pigment of skin, secretions

Question 10

Rifampin

Answer 10

Antymycobacterial-Leprosy
---/RNA polymerase 
(X) combo tx+ dapsone (TB lep)
(X) +dapsone+clofazimine (Lep Lep) 
(-) hepatotoxicity, orange color
INDUCE CYP

Question 11

Amphotericin B

Answer 11

Antifungal-Systemic Gold standard
bind ergosterol, insert in membrane> pore= cell lysis
(X) Broad spectrum (IV 6-12wks)
(-) Ampho-terrible: fever, nasuea/vomit, headache, chills, hypotension, hypokalemia, tachypnea

(-) non-perm nephrotoxic

Question 12

Flucytosine

Answer 12

Antifungal-Systemic
cytosine analog> 5FU–/NA synth
(X) + Amph B: Candida, crytococcus
(+) CSF penetration
(-) GI sxs, leukopenia/thrombocytopenia (bone marrow depression)
(O) renal insufficiency or bone marrow depression

Question 13

Fluconazole

Answer 13

Antifungal-Systemic Triazole
–/14a-sterol demethylase–/lanosterol>ergosterol
(X) Cryptococcus, Candida (CNS and UTI)
(-) GI sxs, rash, headache, mild hepatotoxicity= less bc renal excr (discontinue w onset)
(–) eosinophila, thrombocytopenia
(O) INHIBIT CYP 3A and 2C

Question 14

Itraconazole

Answer 14

Antifungal-Systemic Triazole
–/14a-sterol demethylase–/lanosterol>ergosterol
(X) Blasto, Histo, Candida esopgh and oropharynx (NOT UTI and CNS)
(X) oral - 3mo toenail infection
(-) GI sxs, rash, headache, mild hepatotoxicity (discontinue w onset)
(–) dizziness, vertigo, impotence, HF
(O) INHIBIT CYP 3A > CV events

Question 15

Voriconazole

Answer 15

Antifungal-Systemic Triazole
–/14a-sterol demethylase–/lanosterol>ergosterol
(X)Aspergillus (some CNS), Fusarium, BROADEST Candida (NOT urinary)
(-) GI sxs, rash, headache, mild hepatotoxicity (discontinue w onset)
(–) visual disturbances** blur, color, photophobia, photosensitive rash

Question 16

Capsofungin

Answer 16

Antifungal-Systemic (IV)
NONcompetitive block B (1,3) D-glucan–/cell wall synthesis
(X) invasive Aspergillus (2nd to Amph B and voriconazole)
(X) candida esoph and systemic
(-) GI sxs, flushing/fever, phlebitis @ injection

Question 17

Miconazole

Answer 17

Antifungal-Superficial- ‘monistat’
Itraconazole
(X) Vaginal suppository for candida

Question 18

Clotrimazole

Answer 18

Antifungal-Superficial
Itraconazole
(X) oral- oropharyngeal Candida
(X) vaginal cream- vaginal candida
 (-) abn liver function

Question 19

Nystatin

Answer 19

Antifungal-Superficial
(amph B mech) bind ergosterol, insert in membrane> pore= cell lysis
(X) candida- skin, mucousa, vaginal, GI tract
(X) Azole-resistant candida
(-) GI sxs w oral use

Question 20

Natamycin

Answer 20

Antifungal-Opthalamic
(amph B mech) bind ergosterol, insert in membrane> pore= cell lysis
(X) opthalmic fusarium, aspergillus, cephalosporium
(-) conjunctival chemosis, hyperemia= irritation

Question 21

Tolnaftate

Answer 21

Antifungal-Dermatophyte: topical - cream, spray, powder
inhibit ergosterol synthesis
(X) dermatophyte infec

Question 22

Terbinafine

Answer 22

Antifungal-Dermatophyte: topical= ‘Lamisil’, oral (nail)
-inhibit squalene epoxidase–/ergosterol synth
(X) nail infection (12 wk tx + 12 week remain in system)
(-) diarrhea, dyspepsia, abdm pain

Question 23

Ciclopirox

Answer 23

Antifungal-Dermatophyte: topical
-inhibit metal-dependent fungal enzymes via metal chelation
(X) mild/mod nail infection + 48 weeks w/ nail trimming

Question 24

Griseofulvin

Answer 24

Antifungal-Dermatophyte: oral
–/microtubule funct–/mitosis
–prevent infection of NEW cells
(X) recalcitrant inf of skin, hair, nails (6-12mo tx)
(X) children w tinea capitis
(O) liver disease,CYP INDUCER , penicillin allergies