A persistent challenge in HIV/AIDS treatment and prevention is medication adherence - getting patients to take their medication as required to get the best results.

Currently, a once-daily pill to prevent HIV infection is available. However, adherence to a once-daily regimen can be difficult for some people. Researchers published a study in Nature Communications that reports a potentially promising remedy for this problem. The researchers developed an ultra long-acting, injectable, and removable formulation of an antiretroviral medication called dolutegravir, and they tested the formulation's effectiveness in animal models.

The injectable formulation includes the anti-HIV drug, a polymer, and a solvent. The three-component liquid solidifies into an implant once injected under the skin. As the polymer slowly degrades, the drug is released.

"Our study found that the formulation delivered the drug effectively, and the implants were well tolerated with little or no sign of toxicity, for five months," said co-principal investigator of the study. "It seems to us to be the ideal drug formulation for the prevention and treatment of HIV and AIDS."

The researchers also found that the implant could be quickly and safely removed by making a small incision in the skin at the site of the implant.

Study co-author said this means the implant could be removed if a patient has an adverse reaction, or if a patient becomes pregnant while the implant is in place. This gives it a safety advantage over other long-acting injectables that are currently in clinical trials but cannot be removed after they have been injected, according to the researchers.

http://news.unchealthcare.org/news/2018/october/long-acting-injectable-implant-shows-promise-for-hiv-treatment-and-prevention

https://www.nature.com/articles/s41467-018-06490-w