Fact Sheets on Antiretroviral Drugs

<strong>Fact</strong> <strong>Sheets</strong> on Antiretroviral Drugs
When used alone, to reduce adverse reactions/side effects, a patient should start
treatment with 300 mg twice daily, then gradually increase the dose at 2-3 days
intervals by 100 mg two times a day.
For children, start at 250 mg/m 2 every 12 hours, then gradually increase of 50
mg/m 2 per dose every 2-3 days.
Food effect
It can be taken with or without food; however, taking it with food may improve
tolerability and bioavailability.
Half-life in plasma
From 3 to 5 hours
Metabolism
Mainly in the liver
Interactions with other drugs
� Yes; very strong inhibition of CYP3A4 and of other CYP isoforms
(Cytochrome P450 isoforms)
� If Didanosine or antiacids are administered, they should be taken at least
two hours apart.
� Contraindicated drugs (RTV not to be taken with these drugs):
Amiodarone; Astemizole; Atorvastatin; Bepridil; Cisapride; Clozapine;
Ergotamine and similar alkaloids; Flecainide; Garlic supplements;
Lovastatin; Midazolam; Pimozide; Propafenone; Quinidine; St. John’s wort
(hypericum perforatum); Simvastatin; Terfenadine and Triazolam.
� Ritonavir formulations contain alcohol, which can produce Disulfiram-like
reactions when co-administered with Disulfiram and other drugs that can
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