A recent study found that the HIV pre-exposure prophylaxis (PrEP) medication Truvada protects against hepatitis B infection in addition to HIV infection. The study found that those taking Truvada faced about one-tenth of the risk of hepatitis B infection compared to those not taking it.
The study found that Truvada was more effective at preventing hepatitis B infection than hepatitis B vaccination. The researchers said that at risk people should still receive hepatitis B vaccination as it reduces the symptoms of hepatitis B to almost zero when infections occur after vaccination. The three people in the study who had been vaccinated and still acquired a hepatitis B vaccination were asymptomatic. The lone person in the study on PrEP who was infected with hepatitis B was not vaccinated and was symptomatic. The researchers emphasized that this demonstrates the value of hepatitis B vaccination.
Truvada is a combination of the antiretroviral drugs tenofovir disoproxil fumarate (TDF) and emtricitabine. A previous study found that those taking tenofovir had one-tenth the risk of hepatitis B infection as those not on antiretroviral therapy.
The more recent study investigated whether those same results applied to HIV-negative men taking tenofovir as PrEP. 591 gay and bisexual men were studied, and 148 of them received Truvada for all or part of the follow-up period. 34.5 years old was the average age in the study, with those taking PrEP being an average of 36.7 years old. 14 men not taking PrEP acquired new hepatitis B infections over the course of the study, and only a single man taking PrEP acquired a new hepatitis B infection. This corresponded to an 88.6% reduction in hepatitis B infection for those taking PrEP. Hepatitis B vaccination showed only a 49.5% reduction in hepatitis B infection.
The media recently gave Truvada attention when misleading Truvada ads started to get deleted by Facebook. These ads implied that the risk of serious side effects from Truvada was the same for PrEP users and HIV-positive users using the medication to treat their infections. A 2010 study showed a link between TDF medications, osteoporosis and decreased bone density and a 2018 study showed a link between TDF medication, kidney damage and renal failure. Both studies involved TDF being used to treat existing HIV medications, though. A 2017 study showed that the risk of bone density loss and kidney damage from TDF drugs was higher in those treating HIV infections than in those taking the medications as PrEP.