GENERIC NAME: saquinavir
BRAND NAME: Invirase, Fortovase
DRUG CLASS AND MECHANISM: Saquinavir is an oral medication that is used for treating infections with the
human immunodeficiency virus (HIV). It is in a class of drugs called protease inhibitors which also includes indinavir
(Crixivan),
nelfinavir (Viracept) and ritonavir (Norvir). During infection with HIV, the HIV virus multiplies within the
body's cells. Viruses are released from the cells and spread throughout the body where they infect other cells. In this manner, HIV
infection is perpetuated among new cells that the body produces continually. During the production of the viruses, new proteins are
made. Some of the proteins are structural proteins, that, is, proteins that form the body of the virus. Other proteins are enzymes which
manufacture DNA and other components for the new viruses. Protease is the enzyme that forms the new structural proteins and
enzymes. Saquinavir blocks the activity of protease and results in the formation of defective viruses that are unable to infect the body's
cells. As a result, the number of viruses in the body (the viral load) decreases. Nevertheless, saquinavir does not prevent the
transmission of HIV among individuals, and it does not cure HIV infections or AIDS. Saquinavir was approved by the FDA in December 1995.
GENERIC AVAILABLE: No
PRESCRIPTION: Yes
PREPARATIONS: Capsules: 200 mg
STORAGE: Refrigerate Fortovase capsules at 2-8°C
(36-46°F). When stored at room temperature, Fortovase capsules expire within 90 days.
Store Invirase capsules at room temperature, 15-30°C (59-86°F).
PRESCRIBED FOR: Saquinavir is used for the treatment of HIV infection.
DOSING: The recommended dose of Invirase for adults is 600 mg three times daily, and the dosage for
Fortovase is 1200 mg three times daily. Both formulations should be administered within 2 hours of a meal.
DRUG INTERACTIONS: Saquinavir interacts with many drugs. Some of the important interactions are mentioned
below. Viewers should consult their healthcare provider before combining any drugs with saquinavir.
Saquinavir should not be used together with
triazolam (Halcion),
midazolam (Versed),
sildenafil (Viagra) and ergotamine derivatives (for
example, Ergostat) because saquinavir increases the concentration of these drugs in the body and this could cause serious side effects.
Saquinavir also may inhibit the break-down of the
cholesterol-lowering drugs lovastatin
(Mevacor), simvastatin (Zocor), atorvastatin (Lipitor) and cerivastatin (Baycol). Combining saquinavir with these drugs may increase the occurrence of muscle breakdown
(rhabdomyolysis) which is seen when these drugs accumulate in the body.
Clarithromycin (Biaxin) and ketoconazole (Nizoral) may increase blood
concentrations of saquinavir and cause increased severity or frequency of side effects from saquinavir. Saquinavir also increases the concentration of clarithromycin.
Rifampin (Rifadin) and
rifabutin (Mycobutin) decrease
blood concentrations of saquinavir and therefore could decrease the
effectiveness of saquinavir.
When digoxin is taken by patients receiving saquinavir (Invirase, Fortovase) with ritonavir (Norvir), the
amount of digoxin (Lanoxin) in the body can increase by 50%, possibly leading to side
effects such as potentially fatal rhythm disturbances,
nausea,
vomiting, and
diarrhea, blurred or yellow vision; headache; weakness; dizziness; apathy;
confusion; and mental disturbances such as anxiety, depression, delirium, and
hallucinations.
PREGNANCY: Use of saquinavir during
pregnancy has not been adequately evaluated.
NURSING MOTHERS: It is not known whether saquinavir is
secreted in breast milk. Nevertheless, HIV-infected
mothers should not breast-feed because of the potential risk of transmitting HIV to an infant that is not infected.
SIDE EFFECTS: The most frequent side effects are
headache, weakness, diarrhea, nausea and stomach discomfort. Saquinavir also may cause skin reactions, liver failure, seizures and failure of the
pancreas (pancreatitis). Like
other protease inhibitors, use of saquinavir may be associated with
redistribution or accumulation of body fat, increased cholesterol and worsening
of diabetes.
Last Editorial Review: 11/14/2007
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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- ritonavir, Norvir -
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