Anti-TB drugs

Question 1

FIRST-LINE ANTI-TB DRUGS

Answer 1

ISONIAZID
ETHAMBUTOL
RIFAMPIN
RIFABUTIN
PYRIZINAMIDE
STREPTOMYCIN

Question 2

SECOND-LINE ANTI-TB DRUGS

Answer 2

CYCLOSERINE
ETHIONAMIDE
AMIKACIN
CIPROFLOXACIN
OFLOXACIN
CAPREOMYCIN
PARA-AMINOSALICYLIC ACID

Question 3

What is the Mechanism of action of Isoniazid?

Answer 3

Blocks synthesis of Mycolic Acids for mycobacterial cell wall

Question 4

What is the toxicity of INH

Answer 4

Hepatotoxicity--  
Increases with age of patient
more common in alcoholics
May increase during pregnancy
Increases with age after 35YO; use rifampin for prophylaxis in older patients

Peripheral and central neuropathy– Treat with pyridoxine (Vitamin B6),common in slow acetylators

Question 5

Ethambutol Adverse effects

Answer 5

Dose-dependent optic neuritis, decreased acuity, loss of red-green differentiation

Question 6

Rifampin side affects

Answer 6

Adverse effects--
Inducer of microsomal enzymes
Alters t1/2 of anticoagulants, oral contraceptives
Hepatotoxic
"Flu-like" syndrome
Gives orange color to body fluids

Clinical Use
Combination chemotherapy for active disease, single agent prophylaxis for INH-intolerant patients
Meningococcal infection prophylaxis

Question 7

Mechanism of action of Rifampin

Answer 7

Inhibits bacterial RNA synthesis

Bactericidal

Question 8

Side effects of Pyrazinamide

Answer 8

Cause hyperuricemia

Question 9

Streptomycin adverse effects

Answer 9

Pharmacokinetics, adverse effects typical of aminoglycoside

Question 10

Rifabutin used for

Answer 10

Prevention and Treatment of disseminated atypical mycobacterial infection AIDS patients.

Question 11

Side effects of Rifabutin

Answer 11

Rifabutin is both a substrate and inducer of CYP450, but a less potent inducer than Rifampin.