In addition to birth control, the intravaginal rings of the future may offer antiviral capabilities as well. The newly invented device—called a tenofovir levonorgestrel IVR—is capable of killing HIV and herpes infections. Once inserted this dual-action birth control device remains effective for three months.
Like other intravaginal rings such as the NuvaRing, the tenofovir levonorgestrel IVR is inserted into the vagina where it releases compounds to prevent pregnancy. While other devices release the hormones estrogen and progestin, the tenofovir levonorgestrel IVR releases an anti-spermicide called levonorgestrel. Levonorgestrel is the same medication that is the active ingredient in oral Plan B. It protects against pregnancy by both preventing the release of an egg from the ovaries (ovulation) and also thickening the mucous layers of the cervix and uterus to reduce the chances of sperm making contact with an egg.
In addition to the levonorgestrel anti-spermicide, the tenofovir levonorgestrel IVR releases the antiretroviral drug called tenofovir. Orally administered tenofovir has been used to treat HIV and hepatitis B viruses because of its ability to block viral growth and replication in these viruses specifically. As a vaginal gel, tenofovir has also been shown to be effective at deterring herpes simplex virus.
The tenofovir levonorgestrel IVR is not the first birth control device with antiviral capabilities. Back in 2012 other researchers produced a “pod” intravaginal ring that used both tenofovir and acyclovir to prevent HIV and herpes infection. There is significant interest in creating a contraceptive that specifically protects against these two viruses because epidemiological studies have indicated that an infection with herpes simplex virus increases an individual’s risk of also contracting HIV. The newly invented tenofovir levonorgestrel IVR releases 100 times as much tenofovir as previous models.
If successful, the tenofovir levonorgestrel IVR could significantly impact public health, particularly for women in the developing world. Like other contraceptives that are designed specifically for female use (as opposed to other birth control methods like male condoms), this device might empower women to take the initiative in preventing unwanted pregnancy and disease. It is hoped that because the ring works for several months, women would have more success with it than with other contraceptives that are for one-time use only.
So far the mainstream use of this technology is still a ways in the future. The researchers have tested it on rabbits, but not humans. Particularly because matters of disease and human life are at stake, investigation into human use of the tenofovir levonorgesterel IVR will no doubt need to be extremely thorough.
In addition, the tenofovir levonorgestrel IVR is still not a single magic-bullet. While tenofovir works against HIV and herpes, in the form used in this IVR it does not protect against other kinds of viruses such as HPV or the different kinds of hepatitis. In addition, other kinds of sexually transmitted diseases caused by bacteria (such as Chlamydia and gonorrhea), fungi (different kinds of yeasts), and animals (public lice) are not deterred at all by the tenofovir levonorgestrel IVR.
In addition, one must also consider the health effects of continuously releasing tenofovir and levonorgestrel into the body. In particular, women are advised against using levonorgestrel-based Plan B medication as a regular form of birth control. In addition to that, tenofovir can potentially cause severe damage to the liver and patients must be careful not to overdose. Both medications also can cause side effects such as nausea, vomiting, and loss of appetite. Nevertheless, the discoveries made through the invention of the tenofovir levonorgestrel IVR may prove to be a step towards the mainstream use of devices with both birth control and antiviral capabilities.
By Sarah Takushi