The company that makes ritonavir, Aott Laboratories, recommends building up the dose of ritonavir slowly over a few days when first starting the drug. People can start at 300 mg twice a day, and then move on to 400 mg twice a day after a few days, continuing until you reach the recommended dose of 600 mg twice a day. It is very important that you take no more than 14 days to build up the dose, as this could help HIV get resistant to the effects of the drug. If you can't take the full dose, the lowest dose that can be used is 500 mg twice a day, and this must be in combination with other anti-HIV drugs. The dosage for children is based on the child's size.
Ritonavir comes in capsule and liquid formulations.
The capsules must be kept refrigerated and protected from light. Refrigeration of the liquid is also recommended, but not required if kept in a cool place and used within 30 days. How long it may take to work Maintenance treatment is necessary unless resistance or intolerance to drug occurs, at which time you may be switched to other anti-HIV drugs. Maintenance treatment means you keep taking the drug or drugs to control an infection so that you don't become ill. Anecdotal reports also suggest that taking ritonavir right after a meal with yogurt may help reduce side effects.