Standard Dose: 600 mg (two 300 mg tablets) with 100 mg Norvir, twice daily, with food. Take missed dose as soon as possible, but if more than 6 hours late, do not double up on your next dose; take the next dose on schedule.
Prezista may cause mild to moderate rash, but the most common side effects include diarrhea, nausea, headache, and common cold. Severe rash, while rare, can be life-threatening; notify your healthcare provider immediately. If you experience blistering, mouth sores, conjunctivitis (redness or inflammation of eye, or pink eye, which if untreated may result in permanent vision loss), swelling, muscle or joint aches, fever or general malaise (general ill feeling), you may need to stop all medications, so seek medical attention immediately. Prezista contains a "sulfa" part to it and should be used cautiously by people with "sulfa" allergies. Overall, the rate of adverse effects were similar between Prezista and the comparator group studied, with diarrhea being the most common side effect, seen less in the Prezista groups.
As seen with other protease inhibitors, there can be increased levels of cholesterol and triglycerides (except possibly unboosted Reyataz), although cholesterol changes were similar to those seen with Reyataz in a study of uninfected participants, and better than those seen with Kaletra in two head-to-head studies. Increased cholesterol and triglycerides may be associated with an increased risk of heart disease. Other possible side effects seen with protease inhibitors 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. Immune Reconstitution Inflammatory Syndrome (IRIS) may occur as the immune system regains strength; report symptoms of illness, such as shingles and TB, to health care provider.
Potential drug interactions:
Do not take with midazolam, triazolam, ergot derivatives (such as Cafergot, Wigraine, Methergine, and D.H.E. 45), or the herb St. John's wort. Medications used for seizures such as Tegretol (carbamazepine), Dilantin (phenytoin), or phenobarbital may decrease Prezista/Norvir levels and alternate seizure medications should be used. A reduced dose of rifabutin is recommended. Do not use Zocor, Vytorin, Mevacor, or Pravachol; lipid-lowering alternatives such as Lipitor can be used with caution due to potential for liver toxicity. The antifungal drugs such as itraconazole and ketoconazole may increase levels of Prezista, so caution must be exercised when used together (maximum dose is 200 mg a day for the antifungals). Vfend is not recommended. Prezista/Norvir may decrease Zoloft and Paxil, but no dosing changes are recommended. Kaletra and Invirase lower Prezista levels and Prezista can decrease methadone levels and increase Biaxin levels, but the clinical significance of these interactions is unknown.
Cialis, Levitra, and Viagra levels are increased; doses should not exceed 10 mg Cialis per 72 hours, 2.5 mg Levitra per 24 hours, or 25 mg Viagra per 48 hours. Prezista may increase levels of blood pressure medications called calcium channel blockers, such as Norvasc and others, and they should be monitored for side effects. A lower dose of trazodone is recommended. Monitoring may be required when using Coumadin (warfarin), or immunosuppressants. Increased levels of the inhaled and nasal sprays with fluticasone (found in Advair, Cutivate, Flonase, and Flovent) can occur and therefore should be used with caution. Effectiveness of birth control pills may decrease, consider the use of alternative or additional contraception. Other interactions include Vascor, Lidoderm, Cordarone, Lanoxin, Carbatrol, Rifadin, Rifater, Rifamate, Plendil, Adalat, Cardene, Decadron, Crestor, and Neoral.
Tips:
Prezista is approved for people who are treatment-experienced. Tibotec received community kudos for not pricing Prezista higher than other new PIs. In clinical trials of highly treatment-experienced people, 45% of patients taking Prezista achieved undetectable viral loads (less than 50 copies) when compared to control arm, of which only 12% achieved this. Similar results were found at 48 and 96 weeks. Also, in all these studies there was a significant increase in CD4 T-cell counts in patients taking Prezista. In a recent trial it demonstrated superior viral load responses when compared to Kaletra. Limited information is available in treatment-naïve patients but the dose studied is not commercially available. Please see package insert for more complete potential side effects and interactions.
Doctor
Prezista, the most recently approved PI, is a rising star. It was approved based on the POWER studies, which demonstrated its effectiveness in people with lots of drug resistance, including resistance to PIs. Then came the TITAN study, which found that in people with less extensive drug resistance, it was better than Kaletra overall, and maybe even in those whose virus was still susceptible to Kaletra on resistance tests. Finally, the recent ARTEMIS study found that a lower, once-daily dose of Prezista was at least as effective as Kaletra in people starting therapy for the first time, and more effective in those with high baseline viral loads. Prezista also caused less lipid elevation and diarrhea than Kaletra, though most people were using the older capsule formulation of Kaletra, which may cause more diarrhea. The dose used in that study (800 mg of Prezista plus 100 mg of Norvir once a day) is not available yet -- the closest you could get would be to take three 300 mg tablets of Prezista with 100 mg of Norvir), but the manufacturer is working on a new formulation. Prezista is the new gold standard PI for people with just about any degree of PI resistance, and it's beginning to look promising as a first PI, as well. -- Joel Gallant, M.D.
Activist
Prezista, unlike Aptivus, is easy to use, requires only a small amount of Norvir booster and is genuinely well tolerated. It was initially tested in advanced stage patients with a long history of resistance to multiple classes of drugs. It proved highly effective and durable in this population and appeared to add little toxicity of its own. Later studies demonstrated superiority to a Kaletra regimen in some patient populations. Today, Prezista is widely considered the best or at least among the best of all protease inhibitors. Prezista is difficult to write about from an activist perspective because the drug works very well and the manufacturer has exhibited excellent behavior in its relations with the community. -- Martin Delaney
