Implant-shaped naltrexone often helps HIV-positive overcome opioid dependence
A team of specialists from the University of Pennsylvania, in collaboration with Russian scientists, was able to establish that a naltrexone implant placed under the skin of HIV-positive patients with opioid dependence can reduce the likelihood of relapse and have better results in overcoming the dependence than the oral drug.
When patients with HIV who are also opioid addicted do not have access to adequate treatment, they are more likely to stop taking ART.
While the daily oral form of naltrexone, a drug that dulls the effects of opioids, is one of the most common treatment options for addiction, drug adherence is still known to remain low.
A study published this month in Lancet magazine showed that a naltrexone implant placed under the skin and slowly releasing the drug over three months was more effective at helping HIV-positive opioid-dependent patients and reduced the risk of relapse in comparison with the oral form of the drug.
The study was conducted in Russia, where an oral, injectable and implantable form of naltrexone with prolonged action is currently approved, but at the same time, agonistic or partial agonistic treatment using drugs such as methadone or buprenorphine is illegal.
Agonists continue to be illegal in a number of countries because they activate the same neurological receptors as opioids, and some critics see this approach as a simple substitution of one drug for another.
Naltrexone was approved by the U.S. Food and Drug Administration (FDA) back in the 1970s, however, the only available forms in the country so far are 50 mg tablets and sustained-release injections that block opioids for a month.
“The results are important for the treatment of opioid dependence among patients who do not want to receive an agonist or who live in places where access to it is limited,” said senior author Dr. George E. Woody of the University of Pennsylvania.
“Further development and formal approval of these implants in most countries can provide an effective and meaningful treatment option for opioid dependence in HIV-positive patients.”
In the third phase of a double-blind study, specialists from the First State Medical University. V. M. Bekhterev and the National Medical Research Center for Psychiatry and Neurology of St. Petersburg registered 200 people who applied to medical institutions for help in treating HIV and opioid dependence, and over the next 12 months they evaluated the results of therapy in the first and second cases .
All study participants had not previously received drugs for HIV infection or did not take them throughout the past year, and had viral loads of more than 1000 copies per ml.
Specialists randomly divided volunteers into groups for the provision of a naltrexone implant every 12 weeks and daily oral administration of a placebo (100 people) and a tablet form of naltrexone 50 mg / day along with a placebo implant (100 people). Among all participants, counseling was held once every two weeks regarding drug use and ART.
The results of the work showed that the implant more often than the oral form was associated with cases of better adherence to ART and achieving a low viral load.
At the end of the study, 46 people from the implant group remained on ART compared to 32 members of the oral group. At the same time, 66 people in the implant group had viral loads of less than 400 copies per ml, compared with 50 participants in the oral group.
The remaining patients dropped out of the study. The reasons for this were relapses and death (seven people died from various causes during their work, including heart disease, trauma, overdose, cancer and AIDS).
As the scientists add, the implant group also remained committed to treating addiction and did not experience relapse for a longer period of time: 32 weeks versus 20. According to them, patients in the first group had better results, probably due to longer periods of remission, which in turn, allowed them to focus better on treating HIV than on buying and using opioids.
“Despite the fact that we studied HIV + population only in Russia, these results showed that naltrexone implants can benefit patients in the US and other countries where people do not have access to agonist treatment,” Dr. Woody emphasized. “However, this will largely depend on the results of evaluating the manufacturer’s commercial benefit and regulatory approval of the form.”