Saquinavir mesylate
Saquinavir mesylate
Saquinavir mesylate
((sah- KWIN-ah-veer))
Pregnancy Category: B Fortovase Invirase (Rx)

Classification: Antiviral drug, protease inhibitor

See Also: See also Antiviral Drugs .

Action/Kinetics: HIV protease cleaves viral polyprotein precursors to form functional proteins in HIV-infected cells. Cleavage of viral polyprotein precursors is required for maturation of the infectious virus. Saquinavir inhibits the activity of HIV protease and prevents the cleavage of viral polyproteins. Has a low bioavailability after PO use, probably due to incomplete absorption and first-pass metabolism. A high-fat meal or high-calorie meal increases the amount of drug absorbed. Over 98% bound to plasma protein. About 87% metabolized in the liver by the cytochrome P450 system. Both metabolites and unchanged drug are excreted mainly through the feces. It is believed the bioavailability of Fortovase is greater than Invirase.

Uses: Combined with AZT or zalcitabine (ddC) for treatment of advanced HIV infection in selected clients. No data are available regarding the benefit of combination therapy of saquinavir with AZT or ddC on HIV disease progression or survival.

Contraindications: Lactation. Use with astemizole, cisapride, ergot derivatives, midazolam, terfenadine, triazolam.

Special Concerns: Photoallergy or phototoxicity may occur; take protective measures against exposure to ultraviolet or sunlight until tolerance is assessed. Use with caution in those with hepatic insufficiency. Hemophiliacs treated with protease inhibitors for HIV infections may manifest spontaneous bleeding episodes. Safety and efficacy have not been determined in HIV-infected children or adolescents less than 16 years of age.

Side Effects: Side effects listed are for saquinavir combined with either AZT or ddC. GI: Diarrhea, abdominal discomfort, nausea, dyspepsia, abdominal pain, ulceration of buccal mucosa, cheilitis, constipation, dysphagia, eructation, blood-stained or discolored feces, gastralgia, gastritis, GI inflammation, gingivitis, glossitis, rectal hemorrhage hemorrhoids, hepatomegaly, hepatosplenomegaly, melena, pain, painful defecation, pancreatitis, parotid disorder, pelvic salivary glands disorder, stomatitis, tooth disorder, vomiting, frequent bowel movements, dry mouth, alteration in taste. CNS: Headache, paresthesia, numbness of extremity, dizziness, peripheral neuropathy, ataxia, confusion, convulsions dysarthria, dysesthesia, hyperesthesia, hyperreflexia, hyporeflexia, face numbness, facial pain, paresis, poliomyelitis, progressive multifocal leukoencephalopathy, spasms, tremor, agitation, amnesia, anxiety, depression, excessive dreaming, euphoria, hallucinations, insomnia, reduced intellectual ability, irritability, lethargy, libido disorder, overdose effect, psychic disorder, somnolence, speech disorder. Musculoskeletal: Musculoskeletal pain, myalgia, arthralgia, arthritis, back pain, muscle cramps, musculoskeletal disorder, stiffness, tissue changes, trauma. Body as a whole: Allergic reaction, chest pain, edema, fever, intoxication, external parasites, retrosternal pain, shivering, wasting syndrome, weight decrease, abscess, angina tonsillaris, candidiasis, hepatitis, herpes simplex, herpes zoster, infections (bacterial, mycotic, staphylococcal), influenza, lymphadenopathy, tumor. CV: Cyanosis, heart murmur, heart valve disorder, hypertension, hypotension, syncope, distended vein, HR disorder. Metabolic: Dehydration, hyperglycemia, weight decrease, worsening of existing diabetes mellitus. Hematologic: Anemia, microhemorrhages, pancytopenia, splenomegaly, thrombocytopenia. Respiratory: Bronchitis, cough, dyspnea, epistaxis, hemoptysis, laryngitis, pharyngitis, pneumonia, respiratory disorder rhinitis, sinusitis, URTI. GU: Enlarged prostate, vaginal discharge, micturition disorder, UTI. Dermatologic: Acne, dermatitis, seborrheic dermatitis, eczema, erythema, folliculitis, furunculosis, hair changes, hot flushes, photosensitivity reaction, changes in skin pigment, maculopapular rash, skin disorder, skin nodules, skin ulceration, increased sweating, urticaria, verruca, xeroderma. Ophthalmic: Dry eye syndrome, xerophthalmia, blepharitis, eye irritation, visual disturbance. Otic: Earache, ear pressure, decreased hearing, otitis, tinnitus.

Laboratory Test Alterations: CPK, serum amylase, AST, ALT, total bilirubin. Neutrophils. Abnormal phosphorus.

Drug Interactions: Carbamazepine / Saquinavir blood levels Cisapride / Possibility of serious or life-threatening cardiac arrhythmias or prolonged sedation Clarithromycin / Blood levels of both drugs Cyclosporine / Significant blood levels Dexamethasone / Saquinavir blood levels Ergot derivatives / Possibility of serious or life-threatening cardiac arrhythmias or prolonged sedation Grapefruit juice / Bioavailabilitiy and blood levels of saquinavir Ketoconazole / Saquinavir blood levels Midazolam / Possibility of serious or life-threatening cardiac arrhythmias or prolonged sedation; Plasma levels of midazolam Phenobarbital / Saquinavir blood levels Phenytoin / Saquinavir blood levels Rifampin / Saquinavir blood levels Ritonavir / Saquinavir blood levels Triazolam / Possibility of serious or life-threatening cardiac arrhythmias or prolonged sedation

How Supplied: Capsules: 200 mg.

Dosage
?Fortovase Capsules HIV infections in combination with AZT or ddC.
Six 200-mg capsules (i.e., 1,200 mg) taken t.i.d. within 2 hr of a meal.
?Invirase Capsules HIV infections in combination with AZT or ddC.
Three 200-mg capsules of saquinavir t.i.d. taken within 2 hr of a full meal. This form of the drug will be phased out. The recommended doses of AZT or ddC as part of combination therapy are: AZT, 200 mg t.i.d., or ddC, 0.75 mg t.i.d. However, base dosage adjustments of AZT or ddC on the known toxicity profile of the individual drug.