Treatment of TB, Leprosy, and diarrhea

Question 1

Primary TB - Latent

Answer 1

• Prophy treatment of Isoniazid for 9 months

Question 2

Primary TB - Active

Answer 2

• 2 mon. with Rifamp, isoniazid, pyrazinamide (hepatotoxicity), ethambutol
• 4 mon with rifampin, and isoniazid
• intracellular organisms: treat with RIPE for 12 months + azithromycin (M. bacterium Avium)

Question 3

Secondary TB

Answer 3

• Rule of 5’s: otherwise healthy patients infected with TB have 5% risk of reactivation in the first 2 years and then 5% lifetime risk of reactivation. high risk patients have %5+5% risk of reactivation per year
• Treatment: RIPE + streptomycin

Question 4

Isoniazid

Answer 4

• Use: trophy of TB
• Mech: decreases mycelia acid synthesis; prodrug that must be activated (KatG enzyme).
• Adverse effects: hepatoxicity, always administer isoniazid with Vit B6
• disulfiram-like reaction

Question 5

Pyrazinamide

Answer 5

• Use: treatment of ACTIVE TB
• Mech: inhibits mycelia acid synthesis
• Requires acidic pH to be activated
• Adverse effects: hepatotoxicity (used >2mon)
• increase uric acid
• contraindicated in pregnancy

Question 6

Ethambutal

Answer 6

• Use: treat ACTIVE TB
• Mech: decreases carbohydrate polymerization by inhibiting arbinosal transferase
• Crosses blood brain barrier
• Adverse effects: ocular toxicity, color blindess, ocular neuritis (blindness)

Question 7

Bedaquiline

Answer 7

• Use: multi-drug resistant TB
• Mech: inhibits mycobacterial ATP synthase
• Adverse effects: vomiting and prolonged QT syndrome

Question 8

Dapsone

Answer 8

• Drug of choice for trophy of leprosy and prophy of p. jiroveci
• competes with PABA to inhibit bacterial dihydrofolate synthesis
• Cross-sensitivity if allergic to sulfonamides

Question 9

Rifaximine

Answer 9

• drug of choice for treatment of traveler’s diarrhea