Isoniazid = H oral

Therapeutic action

Antituberculosis antibacterial.

Indications

• Tuberculosis, in combination therapy according to protocol.
• Latent tuberculosis in combination regimens according to protocol.

Forms and strengths

• 100 mg and 300 mg tablets.

Dose

According to protocol.

Duration

• Tuberculosis as monotherapy: according to protocol.
• Latent tuberculosis in combination with daily rifampicin or weekly rifapentine: 3 months.
• Latent tuberculosis in combination with daily rifapentine: 1 month.

Contra-indications, adverse effects, precautions

• Do not administer to patients with severe hepatic impairment.
• May cause peripheral neuropathy, especially in malnourished, alcoholic, diabetic, HIV-infected, pregnant and breast-feeding women, and patients with renal impairment.
• May cause hepatotoxicity, hypersensitivity reactions, psychotic reactions, seizures, and depression.
• Monitor liver function in patients with known hepatic disease.
• If signs of hepatotoxicity develop, discontinue isoniazid until symptoms resolve.
• Administer with caution and closely monitor patients taking phenytoin, carbamazepine, benzodiazepines, or warfarin.
• Administer pyridoxine (vitamin B6) in patients at risk of peripheral neuropathy: child 5 to 10 mg once daily; adult 10 mg once daily.
• Pregnancy: no contra-indication. Administer pyridoxine to the mother.
• Breast-feeding: no contra-indication. Administer pyridoxine to the mother and infant.