General Description:
Invirase brand of saquinavir mesylate is an inhibitor of the human immunodeficiency virus (HIV) protease.  Invirase is available as an opaque hard gelatin capsules for oral administration in a 200-mg strength  Each capsule also contains the inactive ingredients lactose, microcrystalline cellulose, povidone K30, sodium starch glycolate, talc and magnesium stearate.

Molecular Formula: C38H50N6O5 * CH4O3S
Molecular Weight: 766.96, 670.86
See below for Molecular Structure:


HIV protease cleaves viral polyprotein precursors to generate functional proteins in HIV-infected cells.  The cleavage of viral polyprotein precursors is essential for maturation of infectious virus.  Saquinavir mesylate, henceforth referred to as saquinavir, is a synthetic peptide-like substrate analogue that inhibits the activity of HIV protease and prevents the cleavage of viral polyproteins.

Indications and usuage:
Invirase in combination with other antiretroviral agents is indicated for the treatment of HIV infection.  This indication is based on results from studies of surrogate marker responses and from clinical study that showed a reduction in both mortality and AIDS-defining clinical events for patients who recieved who recieved invirase in combination with other antiretroviral drugs compared to patients who received drugs alone.

The recommended dosage is three 200 mg capsules daily.  Invirase should be taken within two hours of completing a meal.  Lower dosages have shown little or no therapeutic effect.

New cases of diabetes mellitus, worsening of pre-existing diabetes mellitus and hyperglycemia have been reported during posmarketing surveillance in HIV infected patients recieving protease-inhibitor treatment.  In some severe cases, diabetic ketacidosis has occured.

The safety profile of invirase in pediatric patients younger than 16 years has not been established.

Fortovase is contrainicated for patients with known hypersensitivity to saquinavir or its components.  It should NOT be administered concomitantly with terfenadine, casapride, astmiazole, triazolam, midazolam, or ergot derivatives.

Potential Adverse Effects:
The majority of adverse events were of mild intensity.  The most frequently reported adverse events among patients receiving invirase were diarrhea, abdominal discomfort, and nausea.