Intravaginal Ring may Help Prevent Transmission of HIV

About 33.4 million people are currently living with the human immunodeficiency virus (HIV), an incurable infection that can be transmitted from infected sexual partners, injection drug use, blood transfusions or organ donations, or during pregnancy, if the mother is infected. Since 1981, more than 25 million people have died from it.

Though there is no known cure for the virus, there are many treatments that can prolong the life of individuals dealing with this illness. However, they can be costly and come with significant side-effects. 

Now, a recent study conducted by the James M Smith's group at the Centers for Disease Control and Prevention in Atlanta, Ga., shows that a novel intravaginal ring mixed with anti-retrovital drug tablets may work as an effective tool for preventing transmission. When implanted, researchers found that the ring was capable of releasing the drug safely for over a 28-day-period.

"The ring maintained steady state drug levels in the vaginal tissues, the key anatomic compartment for preventing sexual HIV transmission, and eliminated the concentration troughs encountered with oral medications," said corresponding author, Marc Baum, in a news release. "This should boost effectiveness."

For the study, researchers tested the drugs Truvada (emtricitabine and tenofovir disoproxil fumarate) and Truvada mixed with maraviroc. Results showed that the ring's topical drug delivery was more effective than oral administration of similar medications. Previous studies have shown that many may not always take their oral medications.

"Issues such as adherence to a regular dosing schedule are significantly reduced by continuous release of the drugs into the vaginal mucosa independently of coitus and daily dosing," Baum added. "In addition, systemic levels are so low as to usually be undetectable in topical delivery. That means that side effects are dramatically reduced, or eliminated entirely."

"The ring maintained steady state drug levels in the vaginal tissues, the key anatomic compartment for preventing sexual HIV transmission, and eliminated the concentration troughs encountered with oral medications," said Baum.

"This should boost effectiveness. In addition, systemic levels are so low as to usually be undetectable in topical delivery. That means that side effects are dramatically reduced, or eliminated entirely," said Baum.

More information regarding the findings were presented in the journal Antimicrobial Agents and Chemotherapy.