When the copies are mature in their formation, they break out to infect other cells. Protease is an enzyme that constructs a coating needed for the virus to survive outside the cell, Dr. Appleby explained. Without this coating, HIV cannot assume its adult, virulent form. Unfortunately, the virus is a resilient adversary. In some patients, the protection offered by drugs is short-lived as the virus adapts and becomes resistant to intervention.
Side effects depend on the medication taken.
The drug Saquinivir, for example, is the least potent protease inhibitor and the easiest for patients to tolerate, Dr. Appleby said. Taken three times every eight hours, this oral medicine may cause loose stools and abdominal cramping. Ritonivir is a very strong protease inhibitor that may interact unfavorably with other medications, giving people a tingling feeling around the mouth, a metallic taste in the mouth, nausea, vomiting and other effects. Patients take six Ritonivirs every 12 hours. These drugs are very expensive.