Standard Dose: Two 500 mg film-coated tablets + Norvir 100 mg two times a day with food, or within two hours after a meal. Cannot be taken without Norvir. Take a missed dose as soon as possible, but do not double up on your next dose. The 200 mg hard-gel capsules are still available.

AWP: $718.56 / month for 500 mg and $646.96 / month for 200 mg

Manufacturer contact: Roche Pharmaceuticals,
www.rocheusa.com, 1 (800) 282–7780

AIDSInfo:1 (800) HIV–0440 (448–0440), www.aidsinfo.nih.gov

Most common are stomach related: diarrhea, abdominal discomfort and nausea. As seen with other protease inhibitors, there can be increased levels of cholesterol and triglycerides (except possibly unboosted Reyataz) which may be associated with an increased risk of heart disease. But it is important to remember the risk of heart disease is determined by many other factors, such as family history of heart disease, smoking, high blood pressure, diabetes, obesity, etc. HIV therapy should not be delayed due to this risk. Other possible side effects are lipodystrophy (body fat changes, including thinning of the face, arms and legs, with or without fat accumulation in the stomach, breasts and sometimes the upper back), onset of new cases or worsening of diabetes (see your doctor promptly) and increased bleeding in hemophiliacs.

Do not take with Tambocor (flecainide), Rythmol (propafenone), Cordarone (amiodarone), Versed (midazolam), Halcion (triazolam), Rifadin (rifampin), Orap (pimozide, a psychiatric drug), ergot derivatives (such as Cafergot, Wigraine and Methergine, D.H.E. 45), garlic supplements, or the herb St. John’s wort (hypericum perforatum). Do not use Zocor (simvastatin) or Mevacor (lovastatin); lipid-lowering alternatives are Lipitor (atorvastatin), Lescol, and Pravachol (parvastatin), but they should be used with caution due to potential for liver toxicity. Recent data show that when rifampin is given with saquinavir/ritonavir, there is significant liver toxicity in 40% of patients.

Viramune, Sustiva and Mycobutin (rifabutin) decrease Invirase levels. Invirase may increase dapsone levels. Antifungals Nizoral (ketoconazole) or Sporonox (itraconazole), used for treatment of candidiasis (thrush) increase the amount of Invirase in the body. Do not take with birth control pills; Invirase reduces level of ethinyl estradiol by 40%. Prescriber may need to adjust doses accordingly. Rescriptor, Crixivan, Norvir, Viracept and Kaletra all significantly increase Invirase’s concentrations. No dosage change when taken with Kaletra.

Protease inhibitors increase blood levels of Viagra (sildenafil citrate), Cialis (tadalafil), and Levitra (vardenafil). Use with caution. Initially the Viagra dose should be 12.5 mg (1/2 of 25 mg tablet) and increased as needed and tolerated. It’s recommended that people on PIs do not exceed 25 mg of Viagra in a 48-hour period because of potential for serious reaction such as low blood pressure, visual changes, and prolonged erection leading to permanent tissue damage. Use Cialis at reduced doses of 10 mg every 72 hours and Levitra at reduced doses of no more than 2.5 mg every 72 hours, with increased monitoring for adverse events.

Due to the discontinuation of Fortovase in early 2006, Invirase is the only formulation of saquinavir available. Switching to its original formulation, Invirase, is matched milligram for milligram. For example, five 200 mg Fortovase (1,000 mg) equals two 500 mg Invirase (1,000 mg). Invirase, the first HIV protease inhibitor out on the market, made a comeback over the past two years, due to study results indicating strong efficacy with fewer side effects when taken with a mini-dose of Norvir, as compared to Fortovase/Norvir. It has the considerable advantage of less diarrhea, vomiting and abdominal distension compared with Fortovase plus Norvir. Invirase/Norvir has demonstrated safety, but the efficacy according to U.S. HIV treatment guidelines is inferior to Kaletra in patients new to HIV treatment. Must be taken with food. There is also some research supporting Invirase 1,000 mg + Kaletra standard dose twice-a-day.