Antimycobacterial Agents

Question 1

What is tuberculosis (TB)? Two types?

Answer 1

Caused by a pathogen mycobacterium tuberculosis when inhaled caused pulmonary infected sputum and develops witihn a few weeks can be latent (never develops on radiograph nor infects others) or active (disease develops causing necrosis or cavitation of lung.

Question 2

Active TB is what?

Answer 2

Active TB and is contagious – need drug prevention and successful tx of ~2 weeks

Question 3

Active TB tx?

Answer 3

Multidrug - decrease risk of resistance

Culture and sensitivity needs to ALWAYS be completed – TB is a slow grower (weeks to months)

INITIAL tx is empiric

Question 4

What primary drugs should you use for Active TB Treatment? Think PIRE!

Answer 4

Pyrazinamide
Isoniazid (INH)
Rifampin
Ethambutol

ALL FOR 8 weeks!

Then INH and Rifampin for 18 weeks

Question 5

What happens if individuals become resistant to certain meds for TB?

Answer 5

INH resistant treat for 6 mo
Rifampin resistant treat for 18-24 mos

ALL with the other 3 drugs not listed

Question 6

What medications are safe across the lifespain for Active TB?

Answer 6

INH and Rifampin for children, pregnant women (cat B) and bfing women

Question 7

Patients who have TB and HIV should be prescribed what?

Answer 7

NOT Rifampin, can interact with antivrials
NEEDS tx for ~24 mos with NEGATIVE sputum cultures

Question 8

Isoniazid (INH) use in active and late TB?

Answer 8

Can be used as single drug tx and prophylaxis for LATENT TB

APART OF MULTIDRUG TX FOR ACTIVE TB (RIPE)

Resistance is a the biggest issue

Monitor LFTs q2 weeks

Question 9

INH a/e?

Answer 9

Peripheral neuropathy - supp with Vitamin B6
CNS effects like agitation, dizziness, hallucinations
Interacts with CYP450 (increases levels of meds like diazepam, phenytoin, etc)
ETOH increases hepatotoxicity

Question 10

Rafampin is prescribed alone or with other meds?

Answer 10

NEVER ALONE, always with other mediations for TB tx (active)

resistance is an issue

Question 11

Rifampin a/e?

Answer 11

Hepatotoxicity LFT q2 weeks
Discoloration of bodily fluids (red-orange)
CYP450 inducer (rapid metabolism)
Oral contraceptives decrease effects

Question 12

Pyrazinamide MOA?

Answer 12

Bactericidal to TB as a combo drug (RIPE)

Question 13

Ethambutol MOA?

Answer 13

USED ONLY FOR MYCOBACTERIA
Bacteriostatic - active against TB resistant to INH and Rifampin

Question 14

Ethambutol a/e?

Answer 14

Optic neuritis - poor color discrimination
Allergic dermatitis
Peripheral neuropathy, renal damage, thrombocytopenia