Zidovudine
Antiviral, Systemic · Nucleoside reverse transcriptase inhibitor
Indications
With other antiretrovirals to treat HIV infection. Monotherapy in HIV-positive pregnant women of over 14 weeks gestation to prevent maternal-foetal transmission and for primary prophylaxis of HIV infection in newborn infants.
Dosage
Adults or adolescents: >30 kg, 250-300 mg twice daily in combination with other antiretrovirals. Children: Under 4 kg, not recommended (except for maternal-foetal transmission); 4-8 kg, use oral soln, 8-13 kg, 100 mg twice daily; 14-21 kg, 100 mg in the morning and 200 mg in the evening; 22-30 kg, 200 mg twice daily; 28-30 kg, 250 mg twice daily. Maternal-foetal transmission: Adults: 100 mg orally five times daily to mother until beginning of labour. Then 2 mg/kg over 1 hr by IV infusion during labour and delivery, followed by 1 mg/kg per hr until cord is clamped. Then to baby, 2 mg/kg orally every 6 hr (or 1.5 mg/kg by IV infusion over 30 min every 6 hr) starting within 12 hr after birth and continuing until 6 wk old.
Adverse Effects
Anaemia, neutropenia, leucopenia, thrombocytopenia, pancytopenia. Severe hepatomegaly with steatosis, raised liver enzymes, pancreatitis, GI upset, lactic acidosis (sometimes fatal), myalgia, myopathy, headache, convulsions, anxiety, depression, dyspnoea, dizziness, insomnia, paraesthesia, cough, nail and skin pigmentation, rash, cardiomyopathy, lipodystrophy, hypertriglyceridaemia, hypercholesterolaemia, insulin resistance, hyperglycaemia, malaise.
Risk Factor (Pregnancy/Lactation)
Pregnancy: Risk cannot be ruled out. Lactation: Contraindicated or not recommended. Contraindications: Low neutrophil cell counts or low haemoglobin levels. Neonates with hyperbilirubinaemia or increased transaminase levels. Moderate to severe hepatic impairment. Precautions: Perform blood tests at least every 2 weeks (weekly for infusion) for first three months of therapy and at least monthly thereafter if patient has advanced disease. Adjust dose if anaemia or myelosuppression occurs or is present. Renal or hepatic impairment, pancreatitis. Risk of immune reactivation syndrome in patients with severe immune deficiency within first few weeks or months of starting combination antiretroviral therapy. Elderly. Pregnancy under 14 weeks gestation (only if benefit to mother outweighs risk to foetus). Discontinue if aminotransferase levels rapidly elevating or with progressive hepatomegaly or…
Interactions
Chronic administration of analgesics, particularly paracetamol. Drugs affecting hepatic glucuronidation or inhibiting hepatic microsomal enzymes. Other potentially nephrotoxic or myelosuppressive drugs. Probenecid; monitor closely for haematological toxicity. Phenytoin, ribavirin, stavudine, fluconazole, valproic acid, methadone, rifampicin, atovaquone, clarithromycin.
Advice to Patient
Take with or without meals. Take precautions to prevent spread of infection. Inform prescriber immediately if there is severe persistent headache or loss of sleep. Regular blood tests are required during therapy. Contact prescriber if there is fever, chills, sore throat, nausea, vomiting, flu-like symptoms, fatigue, burning urination, unusual bruising or bleeding, dark coloured stools, blood in stool, urine or mouth, numbness, pain, tingling of toes or fingers, irritation, skin rash, tremors, muscle weakness occur. Take sufficient amount of fluids (2-3 litres per day) to maintain hydration, unless restricted by the prescriber. Avoid highly crowded places to prevent infections. Do not get vaccinated without consulting prescriber.
Pharmacokinetics
Note: In general, pharmacokinetic data for paediatric patients >3 mths-12 yrs of age are similar to data in adult patients. Absorption: Well absorbed. Metabolism: Hepatic; extensive first-pass effect. Bioavailability: Oral: Similar for tabs, caps and syrup. Neonates <14 days: 89%. Infants 14 days-3 mths: 61%. Infants 3 mths-Children 12 yrs: 65%. Adults: 64% ± 10%. Half-life elimination: Terminal: Premature neonate: 6.3 hrs. Full-term neonates: 3.1 hrs. Infants 14 days-3 mths: 1.9 hrs. Infants 3 mths-Children 12 yrs: 1.5 hrs. Adults: 0.5-3 hrs (mean 1.1 hrs). Time to peak, serum: 30-90 mins. Excretion: Oral: Urine (72%-74% as metabolites, 14%-18% as unchanged drug). IV: Urine (45%-60% as metabolites, 18%-29% as unchanged drug).
Brands with this active ingredient
Compiled by Healify Pharmacy from published drug references. How we compile it →
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