Last Updated June 10, 2016
HIV protease inhibitor antiretroviral
200 mg capsules
Indication: treatment of HIV infection when combined with other antiretrovirals.
Mechanism of action*: inhibits cleavage of viral gag-pol polyproteins precursors into functional proteins by binding to the HIV protease enzyme.
Pharmacokinetics*: metabolized in the liver by CYP 3A4. Inhibits CYP 450 3A4 enzyme. Half life: 7-12 hours.
Use in Renal or Hepatic Insufficiency*:
Use in Pregnancy and Breastfeeding*: Category B. Excretion into breast milk is not known.Use in Children: No recommended use in children.
Very poor bioavailability: should only be used with ritonavir to boost levels into therapeutic range.
Combination of saquinavir and ritonavir may prolong QT and PR intervals. Should not be used with class 1a or 111 antiarrhythmic drugs.
Contraindicated: amiodarone, bepridil, dofetilide, flecainide, lidocaine, propafenone, quinidine, lovastatin, simvastatin, rifampin, cisapride, pimozide, oral midazolam, triazolam, trazodone, dihydroergotamine, ergonovine, ergotamine, methylergonovine, alfuzosin, sildenafil for pulmonary arterial hypertension, clarithromycin, erythromycin, halofantrine, pentamidine, atazanavir, tacrolimus, chlorpromazine, sertindole, clozapine, haloperidol, mesoridazine, phenothiazines, thioridazine, ziprasidone, dapsone, disopyramide, quinine.*
Increased concentrations of concomitant medication: warfarin, tricyclic antidepressants, ketoconazole, itraconazole, clarithromycin, rifabutin (dose rifabutin 150 mg every other day†), alprazolam, clorazepate, diazepam, flurazepam, bosentan, digoxin, calcium channel blockers, fluticasone, atorvastatin, sildenafil, tadalafil, vardenafil, colchicine, salmeterol, fusidic acid, ritonavir, quetiapine, midazolam, cyclosporine, rapamycin. fentanyl, alfentanil, vincamine.*
Decreased concentrations of concomitant medication: methadone, warfarin, ethinyl estradiol.*
Increased concentrations of saquinavir with concomitant medication: streptogramin antibiotics, fusidic acid, proton pump inhibitors, nefazodone.*
Decreased concentrations of saquinavir with concomitant medication: carbamazepine, phenobarbital, phenytoin, dexamethasone, St John’s wort, garlic supplements.*
Drug interactions between saquinavir and other antiretrovirals:*
See above for pregnancy and lactation.
Gastrointestinal symptoms (intolerance, nausea, diarrhoea), QT interval prolongation (Torsades de pointes has been reported, if QT interval ≥ 450 msec saquinavir should not be given), headache, increased liver enzymes, hyperlipidaemia, hyperglycaemia, fat maldistribution, possible increased bleeding in patients with haemophilia, PR interval prolongation.*
*Information from US prescribing information.
†Recommendation from Southern African HIV Clinician Society Guidelines.