Brand name: Lexiva
Generic name: lopinavir/fosamprenavir calcium (fosamprenavir), or FPV
Class: Protease inhibitor (PI)
Manufacturer: ViiV Healthcare, www.viivhealthcare.com, (877) 844-8872
AWP: $947.12/month for 60 tablets; $133.20 for 225 mL oral suspension (50 mg/mL)
Standard Dose: For people on a PI for the first time: two 700 mg tablets with either one 100 mg or two 100 mg Norvir, both once daily; or two 700 mg tablets (without Norvir), twice daily; or one 700 mg tablet with 100 mg Norvir, twice daily. For PI-experienced patients, one 700 mg tablet Lexiva with 100 mg Norvir, twice daily. Available for children ages 2 and older. For people with liver problems, the dose of Lexiva may need to be adjusted and Norvir may or may not be used depending on the degree of liver disease. A grape/bubblegum/peppermint-flavored oral suspension is also available. Can be taken with or without food, with no dietary restrictions, at any dose. Adults must take suspension without food. Take missed dose as soon as possible, unless it is closer to the time of your next dose. Do not double up on your next dose.
Potential side effects and toxicity: Because Lexiva contains a sulfa component, it should be used with caution in patients with allergies to sulfa drugs. The most common side effects may include nausea, rash, diarrhea, headache, and vomiting. 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 monitoring. Patients with hepatitis B or C should be monitored closely for the possibility of elevated liver enzyme levels. Dose adjustment is recommended for people with liver impairment. Side effects and laboratory abnormalities were similar when Lexiva was taken once or twice daily, with or without Norvir. See chart for potential drug class side effects.
Potential drug interactions: PIs interact with many other drugs. See package insert for the most complete list. Tell your provider or pharmacist about all medications, herbs, and supplements you are taking or thinking of taking, prescribed or not. Not recommended to be taken with Kaletra. When taken with Sustiva, boost once-daily Lexiva with 300 mg of Norvir. Do not take with alfuzosin, Revatio, Tambocor, Rythmol, oral Versed (midazolam), Halcion (triazolam), rifampin, Orap (pimozide), or the herb St. John's wort. Should not be taken with Incivek (telapravir), because levels of both Lexiva and telapravir are decreased. Do not use Advicor, Altoprev, Livalo, Mevacor (lovastatin), Simcor, Vytorin, or Zocor (sim- vastatin) for the treatment of high cholesterol. Cholesterol-lowering alternatives are Crestor, Lescol, Lipitor, and Pravacol (pravastatin), but use with caution and start at the lowest dose possible; monitor closely for increased side effects from these medications. Calcium channel blockers (Norvasc, Procardia, and others) should be used with caution and careful monitoring. Lexiva should be taken two hours before H2 blockers (Zantac, Pepcid, and others). Lexiva can lower methadone concentrations. A dose adjustment of Mycobutin (rifabutin) will be needed when used in combination with Lexiva. Steroids, such as Decadron, can decrease levels of Lexiva. Increases levels of fluticasone (found in Advair, Flonase, and Flovent); use only if the benefits outweigh the risks, and monitor for signs of Cushing's syndrome (increased fat in the abdomen, fatty hump between the shoulders, rounded face, red/purple stretch marks on the skin, bone loss, possible high blood pressure, and sometimes diabetes). Alternatives should be considered, particularly for long-term use. Trazodone concentrations may increase; a lower dose of trazodone is recommended. Drug levels of Paxil are lowered; titrate dose based on clinical response. Use caution with anti-convulsants Tegretol (carbamazepine), phenobarbital, and Dilantin (phenytoin). Lexiva may alter Coumadin (warfarin) levels; additional monitoring may be required. Effectiveness of birth control pills may be decreased; consider the use of alternative or additional contraception methods. Cialis, Levitra, and Viagra levels are increased; doses should not exceed 10 mg Cialis per 72 hours or 2.5 mg Levitra per 24 hours, or 25 mg Viagra per 48 hours. Use with caution with Biaxin (clarithromycin), bosentan, salmeterol, immunosuppressants (including transplant drugs), and colchicine (lower the dose). Use of the hepatitis C drug Victrelis (boceprevir) along with a Norvir-boosted PI can potentially reduce the effectiveness of both drugs -- combined use is not recommended.
More information: Last year, U.S. HIV treatment guidelines dropped Lexiva in regimens not containing Norvir as an option for first-time therapy because of inferior potency and the potential for developing cross-resistance to Prezista, a recommended protease inhibitor for first-time treatment. The lower dose of Norvir may cause less of an increase in cholesterol and triglycerides, but there are limited clinical data with this dose. 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 it with your doctor. An analysis from a French cohort showed Lexiva was associated with an increased risk of heart attacks, heart disease, and stroke. A liquid formula of Lexiva is available. See package insert for more complete information on potential side effects and interactions.
Before there was Lexiva, there was Agenerase, which came in enormous, suppository-sized capsules taken at large, stomach-filling doses. The approval of Lexiva, a "pro-drug" of Agenerase, was a big improvement and it had the most versatility of any PI. It could be taken with or without food, with or without Norvir boosting, and once or twice a day. However, a comparison of twice-daily Norvir-boosted Lexiva showed no advantages over Kaletra in terms of effectiveness, safety or tolerability, and Kaletra had the advantage of co-formulation. Later, a once-daily regimen of two tablets (1,400 mg) of Lexiva with 100 mg of Norvir was approved for people who hadn't taken PIs before, but there weren't any clear advantages of this combination over boosted Reyataz or Prezista, which had been more extensively studied. As a result, this worthy PI hasn't been widely used. While it's one of the few PIs that doesn't have to be boosted, the use of unboosted Lexiva can lead to Prezista cross-resistance, and should therefore be avoided.
-- Joel Gallant, M.D., M.P.H.
Originally released in a form known as Agenerase, this drug is an "also ran." It has no real advantage over sturdier regimens, and it was still linked to the Norvir booster problems; it simply never caught on. I guess there may be a few reasons for a handful of folks to use it, but I'm no fan of this one. On to better choices!
-- Joey Wynn
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