 |
Brand name: Invirase
Common name: saquinavir hard-gel (SQV-HGC)
Class: HIV protease inhibitor (PI)
Standard dose: Five 200 mg hard-gel capsules + 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 dose. (New 500 mg formulation available soon.)
AWP: $646.96 / month for 200 mg
Manufacturer contact: Roche Pharmaceuticals, www.rocheusa.com, 1 (800) 910–4687
AIDS Treatment Information Service: 1 (800) HIV–0440 (448–0440) |
| Potential side effects and toxicity: Most common are stomach related: diarrhea, abdominal discomfort and nausea. Because there is low absorption (4 to 6%) of the drug into the body, there are few other side effects. As seen with all other protease inhibitors are increased levels of cholesterol and triglycerides, except possibly unboosted Reyataz (atazanavir) and these increased levels may be associated with heart disease. 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.
Potential drug interactions: Do not take with Tambocor (flecainide), Rythmol (propafenone), Versed, Halcion, Hismanol, Seldane, rifampin, ergot derivatives (such as Cafergot, Wigraine and Methergine, D.H.E. 45, in any form—serious interactions seen with dilation during gynecological exams), garlic supplements, or the herb St. John’s wort. Do not use Zocor (simvastatin) or Mevacor (lovastatin); lipid-lowering alternatives are Lipitor (atorvastain), Lescol, and Pravachol (parvastatin), but they should be used with caution due to potential for liver toxicity.
Viramune, Sustiva and Mycobutin (rifabutin) decreases Invirase levels. Invirase may increase dapsone levels. Antifungal Nizoral (ketoconazole) or Sporonox (itraconazole), used for treatment of candidiasis (thrush), increases 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 (sidenafil 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. 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.
Tips: Invirase, the first HIV protease inhibitor out on the market, has made a comeback, 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 A1 safety and efficacy (the highest category rating) according to U.S. HIV treatment guidelines. This oldie is a goodie. Must be taken with food. There is also some research supporting Invirase 1000 mg + Kaletra standard dose twice-a-day. |
Doctor
Saquinavir was the first protease inhibitor, approved in 1995. Formulated as a hard gel capsule (Invirase), saquinavir was not well absorbed, making it less potent than later PIs. However, its effectiveness improved dramatically when it was co-administered with Norvir. A later soft-gel version (Fortovase) also improved absorption. Side effects are few, though diarrhea is the most common complaint. The pill burden of unboosted saquinavir will intimidate all but the bravest—6 capsules three times a day or nine capsules twice a day! When it is finally reformulated into a smaller number of pills, it may one day compete favorably with other PIs. —Ross Slotten, MD |
Activist
In HIV treatment there’s the same phenomenon as in fashion—everything old is, eventually, new again. In its original hard-gel form, saquinavir had the distinction of being the first protease inhibitor but little else to distinguish it…unless you count a difficult dosing schedule, lots of gut effects, and poor absorption. It faded into the wings when its soft-gel version came to market, only to reappear as the favored saquinavir formulation for use with a ritonavir boost. Ritonavir ups saquinavir exposure, but it can add a layer of gut distress, too. It has also been paired with Kaletra in what tends toward a sledgehammer approach to fighting heavily resistant HIV–cobble together a regimen with the most antiviral power you can find and overcome resistance with sheer brute force …limited only by what one gut can handle. Roche’s new 500 mg. tablet will cut the pill burden by more than half. —Heidi M. Nass |
