5-55
Primary: Base the selection of antimycobacterial drugs on knowledge of local resistance patterns. Usually,
3-4 drugs are initiated. The most common regimen is isoniazid (INH), rifampin (RIF), pyrazinamide (PZA),
and either ethambutol (EMB) or streptomycin (SM). In cases of sensitive tuberculosis, these drugs are given
for 8 weeks, followed by a 6-month course of INH and RIF only. Medicines may be given 2, 3 or 7 times each
week. Use directly observed therapy (DOT) to assure compliance. Treat PPD positive contacts without active
disease (LTBI) with isoniazid, 300 mg/day for 9-12 months. Children under 5 years of age who are contacts
of an active pulmonary case should receive isoniazid, 10-20 mg/kg (300 mg maximum) even if initial PPD is
negative. If the PPD remains negative on retesting after three months, INH may be stopped.
Table 5-1 Antimycobacterial Drugs
Drug Daily dose, Twice weekly Thrice weekly Adverse Monitoring
mg/kg dose, mg/kg dose, mg/kg reactions
(max dose) (max) (max)
INH 5 (300 mg) 15 (900 mg) 15 (900 mg) liver dysfunction, baseline liver
peripheral enzymes
neuropathy
RIF 10 (600 mg) 10 (600 mg) 10 (600 mg) drug interactions, baseline complete
liver dysfunction, blood count, liver
bleeding problems enzymes
PZA 15-30 (2 gm) 50-70 (4 gm) 50-70 (3 gm) liver dysfunction, baseline uric acid,
hyperuricemia liver enzymes
EMB 15-25 50 25-30 optic neuritis baseline and
monthly visual
acuity and color
vision testing
SM 15 (1 gm) 25-30 (1.5 gm) 25-30 (1.5 gm) ototoxicity, renal baseline and repeat
toxicity hearing and renal
function testing
Alternative: Alternate regimens are usually based on results of susceptibility testing.
Patient Education
General: Comply with the medication regimen to avoid developing active disease, and then spreading it
to others.
Medications: See Table 5-1.
Prevention and Hygiene: Isolate patient for several weeks until not contagious. They should use a mask or
cover their mouth with every cough. All contacts should be screened with PPD for active and latent infection.
PPD positive contacts should get chest radiography to rule out active disease.
Follow-up Actions
Return evaluation: Monitor patient monthly for drug toxicity.
Evacuation/Consultation Criteria: Evacuation not necessary unless clinically unstable or patient develops
significant medication side effect. Consult with pulmonologist, infectious disease specialist or primary care
physician prior to treatment and as necessary.
NOTE: Multidrug resistant tuberculosis (MDR-TB) is defined as any M. tuberculosis that is resistant to both
INH and RIF.