Saquinavir Mesylate

A to Z Drug Facts

 Action Inhibits human immunodeficiency virus (HIV) protease, the enzyme required to form functional proteins in HIV-infected cells.

 Indications Treatment of advanced HIV infection. Saquinavir is given in combination with nucleoside analogs (eg, zidovudine).

 Contraindications Coadministration with cisapride, ergot derivatives, midazolam, triazolam.

 Route/Dosage

ADULTS & CHILDREN ³ 16 YR: PO Three 200 mg capsules (600 mg) tid within 2 hrs after a full meal.

 Interactions

Carbamazepine, dexamethasone, nevirapine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine, St. John's wort, other cytochrome P450 3A4 inducers: May increase metabolism of saquinavir and decrease serum levels. Clarithromycin, delavirdine, indinavir, ketoconazole, nelfinavir, ritonavir: May decrease metabolism of saquinavir and increase serum levels. Cisapride, cyclosporine, ergot derivatives, fentanyl, midazolam, triazolam, other drugs metabolized by cytochrome P450 3A4: Serum levels of these drugs may be elevated, increasing the risk of toxicity. Clarithromycin, nelfinavir, sildenafil: Saquinavir may increase levels of these drugs. Aldesleukin, cyclosporine, grapefruit juice: May increase saquinavir serum levels. Warfarin: The anticoagulant effect may be decreased.

 Lab Test Interferences None well documented.

 Adverse Reactions

CNS: Paresthesia; numbness; confusion; seizures; headache; depression; insomnia; anxiety; libido disorder. DERM: Rash; photosensitivity; eczema; verruca; Stevens-Johnson syndrome; bullous skin eruption. EENT: Taste alteration. GI: Diarrhea; abdominal pain and discomfort; nausea; dyspepsia; flatulence; vomiting; constipation; intestinal obstruction. GU: Nephrolithiasis; acute renal insufficiency. HEMA: Acute myeloblastic leukemia; hemolytic anemia; thrombocytopenia. HEPA: Elevated liver function tests; jaundice; portal hypertension. OTHER: Ataxia; fatigue; pain weakness; ascites; pancreatitis; drug fever; intracranial hemorrhage.

 Precautions

Pregnancy: Category B. Lactation: Undetermined. HIV-infected mothers should not breastfeed their infants. Children: Not recommended for children < 16 yr. Clinical chemistry: Perform clinical chemistry tests prior to and at appropriate intervals during therapy. Dosage adjustment: Do not reduce dose; lower doses do not exhibit antiviral activity. Hepatic function impairment: Exercise caution when administering to patients with hepatic insufficiency (liver function tests > 5 times upper limit of normal). Nucleoside analog therapy: Saquinavir must be used in combination with nucleoside analog (eg, AZT [zidovudine], ddC [zalcitabine]) therapy. Photosensitivity: May occur; take protective measures against exposure to ultraviolet light or sunlight until tolerance is determined.

 Administration/Storage

• The medication should be taken within 2 hr after a full meal.
• Doses < 600 mg tid are not effective.
• Store capsules at room temperature in a tightly closed bottle.
• Store Invirase capsules at room temperature in a tightly closed bottle.
• Store Fortovase capsules in the refrigerator 2° to 8°C (36° to 46°F).

 Assessment/Interventions

• Obtain patient history.
• Assess for history of impaired hepatic function.
• Obtain baseline triglycerides, SGOT, SGPT, GGT, CPK, and uric acid. Monitor periodically during treatment.
• Monitor WBC and differential. Note any significant changes.
• Monitor Hct and Hgb frequently (severe anemia may require blood transfusions).

 Patient/Family Education

• Advise patient to take the medication exactly as prescribed.
• Advise patient regarding importance of taking after a meal.
• Warn patient not to alter the dose or discontinue the medication without consulting the health care provider.
• Instruct patient not to take any other medications, including otc medications, without consulting a healthcare provider.
• Explain that a patient will be required to have frequent follow-up blood and urine tests during the course of the treatment and to keep appointments.
• Inform patient that this medication is NOT a cure for HIV infection and secondary illnesses associated with the disease may continue to be acquired.
• Emphasize to patient, family, and significant others that this medication does NOT reduce the risk of transmitting HIV to others through sexual contact or blood contamination.
• Inform patient to report any serious side effects to a health care provider.
• Explain that the long-term effects of this medication are not known, and the initial results have not demonstrated a reduction in symptoms or prolongation of life.
• Caution patient regarding possibility of photosensitivity and to use protective measures until tolerance is determined.
• Advise patient that saquinavir is recommended for use in combination with active antiretroviral therapy and adherence to the prescribed regimen is strongly recommended.
• Advise patient to store Fortovase capsules in the refrigerator 2° to 8°C (36° to 46°F) until the expiration date; once brought to room temperature, use capsules within 3 months.
• Inform patient that redistribution or accumulation of body fat may occur and that long-term health effects are not known.

Books@Ovid
Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts