Saquinavir or Invirase is an anti-viral drug which is used in infections such as HIV and AIDS.
Saquinavir or Invirase is an protease inhibitor which means it blocks an enzyme - protease - which the virus needs to reproduce.
HIV infections have the ability to develop a resistance to Saquinavir or Invirase. For this reason Saquinavir or Invirase is often given in combination with other AIDS drugs which reduces the development of resistance. If resistance does develop, other protease inhibitors - indinavir, ritonavir - can be used.
Saquinavir or Invirase is generally well tolerated. Diarrhea, nausea, and abdominal pain can occur.
People with liver function problems should be careful when taking Saquinavir or Invirase.
Rifampin and rifabutin induce liver enzymes, specifically P450 enzymes, which increase the metabolism of Saquinavir or Invirase and reduce concentrations in the body.
With the non sedation antihistamines, terfenadine and astemizole, Saquinavir or Invirase can produce potentially fatal heart beat irregularities. Saquinavir or Invirase inhibits enzymes which metabolize these antihistamines in the liver, meaning that the levels of the antihistamines increase in the body.
Med Letter 1996;38:35
Ann of Int Med 1996;124:1039
The relevant product monographs must be regarded as the appropriate sources of prescribing information.