“SUS [Brazilian national health care program] promises to distribute medication which eliminates risk of HIV infection” says a headline from a recent news report here in Brazil.
The idea that a person at high risk of getting AIDS could totally prevent the infection by taking one pill a day sounds pretty amazing. But is this true? Let us look at the facts.
The medication in question is Truvada, a combination of two anti-AIDS drugs (tenofovir and emtricitabine), both of which act to block the pathways that the HIV virus uses to infect the body. Research studies suggested that Truvada could be effective as a preventative measure as well as a treatment.
In 2012, public health experts in the US approved the daily use of Truvada to prevent HIV infection in specific cases; for HIV-negative individuals who had a substantial risk of contracting the virus. This included people who had an ongoing relationship with a partner who was HIV positive, non-monogamous individuals who were not consistent condom users, or people who injected illicit drugs.
Truvada was released with significant controversy. Many doctors believed its use would encourage more irresponsible sexual behavior, since people taking the drug might consider themselves immune. Also there were concerns that people would not take the drug every day as prescribed, potentially leading to a resistant HIV infection later.
Since 2012, various global studies have been carried out to see how effective Truvada was as a preventative, and to see if people on the medication were acting less responsibly (those taking the medication were instructed to continue safe sex practices with condoms).
The major findings were published in The Lancet Infectious Diseases in September 2014, and the findings were very encouraging, at least for the people that took the drug as directed. But only 33% of the people in the study were taking the drug 4 or more days per week, and the rest were taking it more sporadically.
But if the participants took the drug at least 4 days per week, they were nearly 100% protected. However, while headlines may claim this drug “eliminates the risk of HIV”, in the real world, where people do not always take their medications as they should, the overall results showed only a 49% lower incidence of HIV infection.
Truvada is also a strong medication, and the most common side effect is stomach and intestinal upsets and headache. Liver and kidney problems are possible but rare. Finally, taking Truvada does nothing at all to help prevent other serious sexually transmitted diseases like syphilis, gonorrhea, herpes, and hepatitis. For this reason, even people taking Truvada daily should be using condoms or other methods to prevent other SDTs.
ANVISA has already approved Truvada in Brazil, but the drug is extremely expensive—up to $12,000 per year in the US. Apparently SUS will approve the drug for use as a daily preventative “at the beginning of next year”. We will keep you updated here.
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Esta postagem também está disponível em: Portuguese (Brazil)