Brand Name: Lexiva

Common Name: fos-amprenavir calcium (FPV)

Class: HIV protease inhibitor

Standard Dose: Once-a-day—two 700 mg tablets with two 100 mg Norvir. Twice-a-day: either two 700 mg tablets (without Norvir) or one 700 mg tablet with 100 mg Norvir. PI-experienced patients should use Lexiva twice daily with Norvir. No food restrictions (may be taken with or without food) with any dosing. Take missed dose as soon as possible, but do not double up on your next dose.

AWP: $658.99 / month

Manufacturer contact: GlaxoSmithKline,
www.lexiva.com, 1 (888) 825–5249

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

Because Lexiva has a “sulfa” part, it should be used with caution in patients with allergies to sulfa drugs. The most common side effects include: nausea, rash, diarrhea, headache, vomiting, fatigue, mood disorders, abdominal pain, and mouth numbness. Rash occurred in about 19% of patients, but severe rashes were uncommon. If you experience a rash, notify your doctor. For mild or moderate rashes, your doctor may choose to continue Lexiva, with close follow-up and monitoring. Side effects and laboratory abnormalities were similar when Lexiva was taken once or twice daily, with or without Norvir.

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. Side effects and laboratory abnormalities were similar when Lexiva was taken once or twice daily, with or without Norvir. 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.

Not recommended to be taken with Kaletra. When taken with Sustiva, boost a once-daily dose of Lexiva with 300 mg of Norvir. There is insufficent data on combining Lexiva, Kaletra and Sustiva—consider using Therapeutic Drug Monitoring (TDM). Do not take with Tambocor, Rythmol, Cordarone, quinidine, Versed, Halcion, Rifadin, Orap, ergot derivatives (such as Cafergot, Wigraine and Methergine, D.H.E. 45), 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 (pravastatin), but they should be used with caution due to potential for liver toxicity. Also avoid certain calcium channel blockers.

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 24 hours, with increased monitoring for adverse events.

Lexiva is now one of the three protease inhibitors recommended by the U.S. HIV treatment guidelines for people on antiviral therapy for the first time. Studies have demonstrated that protease inhibitor-experienced patients should take Lexiva 700 mg with Norvir 100 mg, both twice daily. The once daily dosing is not recommended for treatment-experienced patients for whom a PI therapy has previously failed. It is important to take Lexiva exactly as your doctor instructs, and not to change dosing without discussing with your doctor. The FDA points out that the study comparing Lexiva/Norvir against Kaletra in protease inhibitor experienced patients was not large enough to show that the combination was clinically equivalent to Kaletra.

Lexiva is a “pro-drug” formulation of amprenavir (Agenerase). This means that when you take this pill, your body converts it to Agenerase. 700 mg of Lexiva is roughly equivalent to 600 mg of Agenerase. This new formulation is an improvement because it helps to make the pills smaller and easier to swallow. The new formulation also allows the drug to be given with fewer number of pills per day (4 per day). The liquid formula of Agenerase is still available.