VANCOUVER — Increasing access to methadone treatment through primary-care doctors and pharmacies significantly cuts the spread of HIV, according to research involving Vancouver residents addicted to opioids.
Injection drug users who were not prescribed methadone were almost four times more likely to become HIV-positive, found the study, published in the medical journal The Lancet HIV.
Methadone treatment prevents withdrawal from opioids such as heroin.
The findings provide critical support for British Columbia's methadone maintenance program, which is currently being reviewed by the provincial government, the study's lead author said.
"If you were on medication for your diabetes but you had to travel across your city to get your medication every day from a specialty clinic, and not go to your pharmacy around the corner, you'd be significantly less likely to go," said Dr. Keith Ahamad, with the BC Centre for Excellence in HIV/AIDS.
"As a result, the consequences related to your diabetes would be much higher. So what we really need to do is increase access to this medication."
The treatment has been controversial, and the government's review involves some pharmacies being shut down because staff were providing financial incentives to patients filling their prescriptions.
Overall, the province has been supportive of the strategy to combat transmission of the AIDS-causing virus, Ahamad said.
Health Canada handed responsibility for methadone programs to the provinces in 1996, when the new study began.
Between 1996 and 2013, researchers followed 1,639 HIV-negative injection drug users. They found the vast majority of 138 people who were infected with HIV over that time were not taking methadone.
Ahamad said people who can easily obtain methadone treatment may be less likely to engage in risky behaviours associated with spreading the virus.
HIV can spread through unprotected sex and sharing injection drug equipment such as needles with someone who has the virus.
"Irrespective of all those other risk factors, methadone is protective," Ahamad said.
HIV infections are rising where methadone treatment is illegal or only prescribed in specialty clinics — in jurisdictions such as in Russia and Indiana state, he said.
British Columbia's strategy can be used as a model within Canada, where treatment barriers still remain in some places, Ahamad said.
Patients in rural areas are harder to serve, Ahamad said, adding not all primary-care doctors are fully trained to provide the intervention.
In B.C., physicians can take a one-day course to write methadone prescriptions.
