Brand Name: Prezista

Common Name: darunavir (formerly TMC-114)

Class: HIV protease inhibitor

Standard Dose: 600 mg (two 300 mg tablets) with 100 mg Norvir, twice daily, with food. Take missed dose as soon as possible, but do not double up on your next dose.

AWP: $937.50 / month

Manufacturer contact: Tibotec Therapeutics, www.prezista.com, 1 (866) 889–2074

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

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 (see Viramune). 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 arm studied, with diarrhea being the most common side effect.

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. 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.

Do not take with Tambocor, Rythmol, Cordarone, Versed, Halcion, Rifadin, Orap, ergot derivatives (such as Cafergot, Wigraine and Methergine, D.H.E. 45), garlic supplements, or the herb St. John’s wort. Medications used for seizures such as Tegretol, Dilantin 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, Mevacor, or Pravachol; lipid-lowering alternative such as Lipitor can be used with caution due to potential for liver toxicity. The antifungal drugs such as Sporanox and ketoconazole may increase levels of Prezista, so caution must be exercised when used together (maximum dose is 200 mg a day). Vfend is not recommended. Prezista/Norvir may decrease the antidepressants Zoloft and Paxil, but no dosing changes are recommended.

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, Procardia, and others, and they should be monitored for side effects. Prezista/Norvir may decrease methadone levels but withdrawal rarely occurs; dosing adjustment may be necessary to avoid withdrawal symptoms. A lower dose of Desyrel is recommended. Monitoring may be required when using Coumadin, or immunosuppressants. Increased levels of the inhaled and nasal sprays with fluticasone (found in Advair, 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.

Prezista is the newest approved protease inhibitor for people who are treatment-experienced. Tibotec received community kudos for not pricing Prezista higher than other new PIs. In clinical trials, 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 weeks. In addition, 58% of patients using Fuzeon for the first time during the trial with Prezista had undetectable viral load (less than 50 copies) compared to 11%. Also, there was a significant increase in CD4 T-cell counts in patients taking Prezista. It has not been studied in treatment-naïve patients.

The newest PI to hit the market, Prezista (like Aptivus) works against virus that is resistant to other protease inhibitors. It requires less ritonavir boosting than Aptivus, and doesn’t have the same liver toxicity issues associated with it. Overall it is generally well-tolerated with the same expected side effects seen with most other PIs. So far anecdotally among the community we’ve been hearing good things since its launch. It is definitely geared towards people who are treatment experienced, but as we learn more that indication may become broader. The company that created it—Tibotec—also has a new NNRTI called TMC-125 coming right behind it, which is also targeting resistant virus (see etravirine). Another exciting thing about this new PI is the fact that it is going to be part of a new clinical trial focusing on women called the GRACE study, which stands for Gender, Race, And Clinical Experience. This study is one of the first of its kind (and definitely the first in a long time) that looks at the differences between men and women when it comes to HIV drugs. It is opening across the country at a variety of sites. It is targeting treatment experienced patients (70% women and 30% men). Kudos to Tibotec for taking a step forward in gaining more info about women. Now if all the companies would just follow suit we could really get somewhere.—Cathy Olufs