Atazanavir Oral: Dosing, Interactions, and Precautions

Therapeutic action

Antiretroviral, HIV protease inhibitor.

Indications

HIV infection, in combination with ritonavir booster and other antiretrovirals.

Forms and strengths

• 200 mg capsule.
• 300 mg atazanavir/100 mg ritonavir tablet.

Dose

• Child 10 to < 25 kg: one 200 mg capsule once daily plus 100 mg ritonavir once daily.
• Child >= 25 kg and adult: one 300 mg/100 mg tablet once daily.

Duration

Depending on the efficacy and tolerance of atazanavir and ritonavir.

Contra-indications, adverse effects, precautions

• Do not administer to patients with severe hepatic impairment.
• Administer with caution and monitor use in patients with haemophilia or mild to moderate hepatic impairment.
• May cause jaundice, gastrointestinal disturbances, headache, insomnia, fatigue, peripheral neuropathy, asymptomatic hyperbilirubinaemia, cholelithiasis, urolithiasis, conduction disorders, hyperglycaemia, hyperlipidaemia, and lipodystrophy.
• Skin rash may be severe and hepatic disorders may occur; in this event, stop treatment immediately.
• Do not combine with rifampicin or omeprazole. Replace rifampicin with rifabutin. If omeprazole is necessary, do not exceed 20 mg daily and take each drug 12 hours apart.
• Administer with caution and monitor combination with drugs that prolong the QT interval, including amiodarone, co-artemether, mefloquine, quinine, and haloperidol.
• Do not administer simultaneously with antacids containing aluminium or magnesium hydroxide; take 2 hours apart.
• Atazanavir in combination with ritonavir reduces the efficacy of implants and oral contraceptives. Use injectable medroxyprogesterone, an intrauterine device, or an oral contraceptive containing at least 30 micrograms of ethinylestradiol per tablet.
• Pregnancy: no contra-indication; monitor bilirubin levels and/or signs of jaundice in neonates.