Emtricitabine + tenofovir to prevent HIV transmission. More evaluation needed.
Regular condom use is the standard method for preventing HIV transmission during insertive intercourse. Effective treatment of infected individuals also reduces the risk of transmission. However, even when these preventive measures are used correctly, they are not completely reliable. Emtricitabine (a nucleoside) and tenofovir (a nucleotide) are HIV reverse transcriptase inhibitors. The combination of these 2 drugs has been authorised in the United States for the prevention of HIV-1 infection in adults at high risk, in combination with other preventive measures. Clinical evaluation is based mainly on two double-blind placebo-controlled trials. In a trial involving 2499 men or transgender women (born male) who have sex with men, conducted outside Europe, the incidence of infection was lower among patients treated with emtricitabine + tenofovir than with placebo (2.3 versus 4.3 per 100 person-years, p = 0.005). A subgroup analysis showed no added preventive effect of this treatment among condom users. Another trial including 4758 heterosexual couples in which only one partner was infected, conducted in Uganda and Kenya, showed a lower incidence of HIV infection in the emtricitabine + tenofovir group than in the placebo group after one year of treatment (0.50 versus 1.99 per 100 person-years). No statistically significant difference was found between the emtricitabine + tenofovir combination and tenofovir single-agent prophylaxis. Drug prevention showed no added efficacy in this trial among patients who regularly used condoms. Other trials conducted in Africa among heterosexuals favour the preventive efficacy of emtricitabine + tenofovir, except in one trial in which adherence appeared to be very poor. These trials did not identify any previously unknown adverse effects of emtricitabine + tenofovir. Tenofovir can cause kidney failure. Data from a US registry of pregnancies exposed to emtricitabine or tenofovir rule out any major risk of teratogenicity. In situations in which there is a high risk of HIV transmission, daily intake of emtricitabine + tenofovir appears to roughly halve the risk of sexual transmission, without eliminating it completely. In Western Europe, only persons with infected partners and those who engage in risky sexual practices without condoms are at high risk of infection. Long-term assessment of emtricitabine + tenofovir is justified in these situations, despite the mixed results of previous trials.
D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D017280:Condoms / Q000706:statistics & numerical data; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004338:Drug Combinations; D000069480:Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; D005260:Female; D015658:HIV Infections / Q000517:prevention & control* / Q000635:transmission; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D006801:Humans; D008297:Male; D009943:Organophosphorus Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D018894:Reverse Transcriptase Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D012306:Risk; D012309:Risk-Taking; D012725:Sexual Behavior
D019380:Anti-HIV Agents; D004338:Drug Combinations; D000069480:Emtricitabine, Tenofovir Disoproxil Fumarate Drug Combination; D009943:Organophosphorus Compounds; D018894:Reverse Transcriptase Inhibitors; D003841:Deoxycytidine; D054303:HIV Reverse Transcriptase