Antiretroviral Medication as Prophylaxis
Preexposure Prophylaxis (PrEP) with antiretroviral drugs is a concept that is gaining increased recognition as a method of primary prevention for people with a risk of becoming infected with the Human Immunodeficiency Virus. We know what works best in the prevention of HIV but human nature, mainly when guided by their sexual drive, will not always follow the best advice – a fact that even the Catholic church must have realised by now.
Recent clinical trials show promising results for the use of PrEP when delivered as part of a comprehensive set of prevention services for individuals at high risk for HIV acquisition. This approach works best when accompanied by regular monitoring of HIV status, side effects, adherence and risk behaviours.
It is biologically plausible that antiviral medication could affect the acquisition of HIV especially when the prophylactic drug has a long half-life, achieves a high concentration in monocytes, macrophages and genital secretions, has a high barrier to genetic resistance and is safe and inexpensive.
Tenofovir seems to tick all these boxes and is the most widely studied substance either in combination with Emtricitabine (Truvada) or on its own.
The danger of PrEP facilitating resistance and thus spreading a drug-resistant virus is a possibility, especially if this method becomes widespread.
A possibility exists that offering PrEP could encourage increased high-risk sexual activity. However, no evidence of increased high-risk sexual activity was demonstrated in the few observational studies that addressed this.
High-risk individuals include those who have a partner known to be HIV infected or who are sexually active within a high prevalence area. In the gay community, the use of PrEP is becoming a regular feature especially in men participating in anal intercourse.