One effort in developing new tools for HIV prevention is to think of things people would normally do when preparing for sex so that they don't need to remember an extra step, such as taking a pill every day. For example, many people who engage in anal sex as the receptive partner (or "bottom") have a ritual of diet and douching to prepare for the sex act.
Ethel Weld, M.D., with Johns Hopkins University School of Medicine, and her colleagues therefore developed an anal douche with tenofovir (TFV) to assess whether the drug would concentrate in the rectal tissue or in the blood enough to provide the same protection as at least four pills of emtricitabine/TDF a week.
With 18 men who have sex with men (MSM) volunteers, they tested three different formulations of TFV (220 mg with saline, 660 mg with saline, and 660 mg with half-normal saline) in six MSM in each arm and collected blood and colorectal samples for one week.
They found that, while the blood levels of TFV were well below protective levels (as was expected since it wasn't delivered in pill form), the levels of TFV in all three groups were well above what was considered protective against HIV without the use of condoms within one-three hours of use and still above protective levels at 24 hours. It was also safe, acceptable, and well tolerated by participants.
"The prevention community is in the process of rising to meet the challenge of peoples' widely varying circumstances, preferences, behaviors, and risks contexts for HIV, and that challenge must be met with just as wide a variety of prevention technologies," said Weld. "An on-demand tenofovir douche that is not only safe and efficacious but also aligned with peoples' existing sexual behaviors, and there aligned with pleasure, is one way of meeting that challenge, and we strongly feel it should be advanced with further clinical development."