Use of anti-tuberculosis drugs in special situations

Clinical description

The following special situations require an adjustment of standardized TB regimens.

Pregnancy

• Streptomycin is potentially ototoxic and may cause deafness in infants.
• Streptomycin should not be given in pregnancy.
• Isoniazid, rifampicin, pyrazinamide and ethambutol are safe in pregnancy.
• Pyridoxine supplementation is recommended for all pregnant and breastfeeding

women receiving isoniazid.

Oral contraceptives

• Rifampicin reduces the effectiveness of the oral contraceptive pill.

56 National Tuberculosis Control Programme

• Health workers should advise patients on TB treatment to use barrier contraception

like male or female condoms while on rifampicin.

Renal impairment and renal failure

• Ethambutol and pyrazinamide are cleared by the kidneys and should be reduced to

three times per week.

• Streptomycin should be avoided in patients with renal failure, or, if it must be used, the

frequency should be reduced.

Table 7.1-5: Recommended dosages in patients with renal failure Normal Frequency in Drug Dose frequency renal failure Pyrazinamide 25 mg/kg Daily 3x/week (Z)

Ethambutol (E) 15 mg/kg Daily 3x/week Streptomycin 15 mg/kg Daily 2-3x/week (S)

Liver impairment and liver failure

• Isoniazid, rifampicin and pyrazinamide are recognized to be hepatotoxic.
• TB patients with active liver disease (i.e., those with jaundice or ascites) should not

receive pyrazinamide or rifampicin.

• They should be given 2 months of streptomycin, isoniazid and ethambutol during the

intensive phase of treatment, followed by 10 months of isoniazid and ethambutol.

• If the jaundice is acute and severe, then treat initially with only streptomycin and

ethambutol.

Epilepsy

• Rifampicin induces liver enzymes that reduce levels of anticonvulsant medications

(phenobarbital and phenytoin) in the blood.

• Increase the dose of the anticonvulsant and monitor the patient closely for increasing

seizure frequency.