Brand name: Prezista

Generic name: darunavir, or DRV

Class: Protease inhibitor (PI)

Manufacturer: Janssen Therapeutics,, (877) JANSSEN (526-7736)

AWP: $1,271.09/month for 600 mg tablets; $1,482.99 for 400 mg tablets

Standard Dose: 800 mg (two 400 mg tablets) with 100 mg Norvir once daily with food for first-time therapy and treatment-experienced adults without Prezista-related HIV resistance, or 600 mg (one 600 mg tablet) with 100 mg Norvir twice daily with food for those who have been on other HIV medications in the past and failed those medications and have at least one Prezista-related HIV drug resistance mutation. Prezista should never be taken without Norvir. 75 mg and 150 mg tablets available for children over six, dose based on weight. An oral suspension for children three years or older and adults who have difficulty swallowing pills is available. Please see the new package insert for specific directions on how to take the oral solution based on weight. As with the Prezista tablet, the oral solution needs to be taken with Norvir. Take a missed dose as soon as possible, but not if more than 12 hours past the once-daily dose (or six hours past the twice-daily dose). Do not double up on your next dose; take the next dose on schedule.

Potential side effects and toxicity: Prezista contains a sulfa component, and should be used cautiously by people with sulfa allergies. Prezista may cause mild to moderate rash (0.4% of people taking it), accompanied by fever and/or elevations of AST/ALT (liver enzymes) in some cases, but the most common side effects may include diarrhea, nausea, headache, rash, and abdominal pain. Liver function should be measured before starting therapy and should be monitored. Increased monitoring should be considered for people with underlying chronic hepatitis B or C, cirrhosis, or elevated levels of AST/ALT, especially during the first several months of therapy. No dose adjustment is necessary for those with mild to moderate liver disease, but Prezista/Norvir is not recommended for people with severe liver impairment. Severe rash, while very rare (in less than 0.1% of those taking it), can be life-threatening. Seek medical attention immediately. You may need to stop all medications. 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. Do not take with alfuzosin, Revatio, oral Versed (midazolam), triazolam (Halcion), Ergomar, ergonovine, methylergonovine, the herb St. John's wort, cisapride, pimozide (Orap), and rifampin. Should not be taken with Incivek (telapravir), because levels of both Prezista and telapravir are decreased. Prezista may decrease levels of phenytoin (Dilantin), phenobarbital, and Tegretol; levels should be monitored. A reduced dose of rifabutin is recommended. Do not use Advicor, Altoprev, Mevacor, Simcor, Vytorin, or Zocor for the treatment of high cholesterol. Cholesterol-lowering alternatives are Crestor, Lescol, and Lipitor, but should be used with caution and started at the lowest dose possible; you should be monitored closely for increased side effects from these medications. Pravacol (pravastatin) cannot be used with Prezista in the presence of liver impairment. The antifungal drugs such as itraconazole and ketoconazole may increase levels of Prezista, and Prezista may increase theirs, so caution must be exercised when used together (maximum dose is 200 mg a day for the antifungals). Vfend should not be used unless the benefits outweigh the risks. Cialis, Levitra, and Viagra levels are increased; doses should not exceed 10 mg Cialis or 2.5 mg Levitra per 72 hours, or 25 mg Viagra per 48 hours. Prezista may increase levels of calcium channel blockers, such as Norvasc and others, and beta-blockers, such as propanolol; clinical monitoring is recommended. A lower dose of trazodone and desipramine may be recommended. Close monitoring of INR levels required when using Coumadin (warfarin). 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. Effectiveness of birth control pills may be decreased; consider the use of alternative or additional methods of contraception. No dose adjustment required with buprenorphine (Subutex or Suboxone) or methadone. Monitoring of antidepressant response is recommended with selective serotonin reuptake inhibitors (such as Paxil, Zoloft). Use with caution with bosentan, salmeterol, immunosuppressants, and colchicine; use lower dose of colchicine. 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: Prezista is a preferred PI for initial therapy in the DHHS HIV guidelines. Last year, Janssen Therapeutics entered into agreements with Gilead Sciences for the development of two fixed dose combinations (co-formulations) of Prezista -- one with the booster cobicistat, emtricitabine, and GS-7340, a pro-drug of tenofovir (this would be the first STR using a protease inhibitor); and also for a co-formulation with cobicistat. The use of built-in cobicistat would both eliminate Norvir and reduce pill burden. Janssen received community praise for not pricing Prezista higher than other new PIs when it came on the market. See package insert for more complete information on potential side effects and interactions.

Doctor's Comments

Prezista started out as the best of the "second-generation" PIs, showing excellent activity in most people with PI-resistant virus. Then it was shown to be more effective and more "resistant to resistance" than Kaletra in people who had taken PIs before but whose virus was susceptible to both drugs. A later study found that a once-daily dose of Prezista/Norvir had a number of advantages over Kaletra for first-line therapy, including less diarrhea, less lipid elevation, and better activity at higher viral loads. The latest development has been the approval of the once-daily dose for treatment-experienced patients who have no Prezista mutations. In short, you could say it's the "PI for all seasons." The main downside of Prezista is that it's more likely than other PIs to cause an allergic rash, and, unlike the rash with Sustiva, a rash on Prezista often requires a switch to a different drug. Prezista must always be taken with Norvir, and with food.

-- Joel Gallant, M.D., M.P.H.

Activist's Comments

Prezista replaced Kaletra as ruler of the roost, even though Reyataz is nipping at its heels. It has fewer side effects than the older PIs, but it does still have many of the drug interactions common to the older drugs. Janssen earned kudos from the HIV advocacy community over their pricing policies. Easy access websites allow for PAPs and co-pay cards for those with insurance coverage. Oddly enough, for many of us who never saw CD4 increases with our undetectable viral loads over the years, this gem can really crank up the CD4 counts for us. One of my personal favorites!

-- Joey Wynn

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