Brand name: Truvada
Generic name: emtricitabine/tenofovir, or FTC/TDF
Class: Nucleoside/nucleotide reverse transcriptase inhibitor (nucleoside/nucleotide, NRTI, or nuke) -- fixed dose combination
Manufacturer: Gilead Sciences, Inc., www.gilead.com, (800) GILEAD-5 (445-3235)
Standard Dose: For adults and pediatric patients 12 years or older and weighing more than 77 pounds, one tablet (200 mg emtricitabine/300 mg tenofovir) once a day, with or without food, with no dietary restrictions. Dosing frequency needs to be adjusted for people with decreased kidney function and Truvada should not be used if the kidney function is less than 30 mL/min or if on dialysis. 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: See the individual drugs contained in Truvada -- Viread and Emtriva. Overall, fairly well tolerated, however, individuals may experience diarrhea, nausea, vomiting, and gas. Skin discoloration on palms and soles may also occur. The Viread in Truvada is associated with decreases in bone mineral density (BMD). BMD monitoring should be considered in people who have a history of pathologic bone fracture or are at risk for osteopenia or osteoporosis. The effects of calcuim supplements with or without vitamin D have not been studied, but their use may be beneficial. Calcium and vitamin D levels can be checked by your provider to assess the need for these supplements. Less common side effects include kidney toxicities and low blood phosphate. See chart for potential drug class side effects.
Potential drug interactions: See the individual drugs contained in Truvada -- Viread and Emtriva. Do not take with Atripla, Combivir, Complera, Emtriva, Epivir, Epivir-HBV, Epzicom, Trizivir, Truvada, or Viread, since all or part of these medications are already in Truvada or have equivalent medications. Truvada increases levels of Videx EC, so use with caution and monitor. Tenofovir decreases the concentration levels of Reyataz. In addition, Reyataz and Kaletra increase tenofovir concentrations. The reason for these interactions is unknown. It is recommended that patients taking Reyataz and Truvada should be monitored for Truvada-associated adverse events. When taken with Truvada, it is recommended that Reyataz 300 mg is taken with Norvir 100 mg (all as a single daily dose with food). Reyataz without Norvir should not be taken with Truvada. No dose adjustment is needed when used with Kaletra. Avoid taking Truvada with current or recent use of kidney-toxic drugs.
More information: Currently, DHHS HIV treatment guidelines recommend Truvada over Epzicom as the only preferred medication for the NRTI component for first-time therapy. Study ACTG 5202 reported that while both Epzicom and Truvada reduced viral load, for those people who started treatment with a viral load of more than 100,000, Epzicom was "significantly less effective at controlling HIV" in the regimens tested. Moreover, time to a serious adverse event was sooner in the people taking Epzicom. Remember, however, that Truvada has its own side effect and drug interaction issues, although it's famed for its tolerability. Kidney function must be monitored before and during treatment with Truvada and it may not be a good option for patients with underlying kidney problems. GS-7340, a pro-drug (substance that becomes activated after entering the body) of tenofovir, is being developed. The pro-drug has the same mechanism of action, but is expected to provide greater effectiveness at a dose 10 times lower than that used for Viread. A tablet containing Emtriva and GS-7340 has been developed and is being studied. This would be Emtriva with GS-7340 instead of tenofovir. Truvada is combined with efavirenz to form Atripla and is also in the new Complera, another triple regimen in one pill. Truvada is also in advanced Phase 3 study in a quadruple formula with two of Gilead's investigational drugs: elvitegravir, an integrase inhibitor (same class as Isentress), and the drug booster cobicistat (GS-9350); see the "Quad." Gilead has applied for FDA approval of Truvada as HIV prevention, which is called PrEP (for pre-exposure prophylaxis). Truvada PrEP is controversial, with some people rooting for it and others worried that it will be used incorrectly, among other concerns. At any rate, Truvada can already be used off label (not an FDA approved use) for prevention. Although the effect of supplementation with calcium and vitamin D has not been studied, such supplementation may be beneficial for all patients, according to the FDA. See package insert for more information on potential side effects and interactions.
Truvada is now the preferred nucleoside backbone for initial regimens according to DHHS and IAS-USA guidelines, based on studies showing that it's more effective and safer than Combivir, and more effective at high viral loads than Epzicom. When combined with efavirenz (Sustiva), it is used in the form of Atripla, the first approved single-pill regimen and, combined with rilpivirine, it forms Complera, the second approved single-pill regimen. People taking Truvada need to be monitored for kidney toxicity (see Viread), and those who already have kidney disease may need to take Truvada less frequently than once a day, or better yet, avoid it altogether. The bone issues seen with tenofovir (see Viread) also apply to Truvada.
-- Joel Gallant, M.D., M.P.H.
The little train that could! Who knew that this combination would become the blockbuster it is today? Part of the majority of regimens prescribed today, it is (for many people) easy to take, with few side effects for the average person. Its only downside is that there are no comparable alternatives for those who need to avoid the possibility of kidney toxicity and possible bone loss reported by some. I've been on this for a decade, before the two components were in one pill and I can't imagine having to stop taking it. Only adding the final drug to it could make it better, and guess what? There are now two once-daily single tablet regimens with this super couple in it -- Atripla and Complera both contain Truvada. Getting it down to one pill once a day is the gold standard now.
-- Joey Wynn
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