Ontario will soon cover a combination HIV prevention pill that is now available in generic form, HIV advocates say.

The once-daily pill contains two anti-HIV drugs that reduce the risk of sexual transmission in HIV-negative individuals.

Pre-exposure prophylaxis, or PrEP, originally cost about $1,000 a month as the brand name Truvada. The drug was first introduced to treat HIV.

Ontario's Health Ministry added the PrEP drug to its formulary of publicly covered drugs on Thursday, effective Sept. 28.

In 2016, Health Canada approved Truvada (emtricitabine 200mg/tenofovir disoproxil fumarate 300mg) in combination with safer sex practices to reduce the risk of sexually acquired HIV among adults at high risk of exposure to the virus.

Since then, generics costing a quarter as much have become available, said pharmacist Michael Fanous in Toronto.

"The generics are now at 450 per month and there are others entering the market at half that price," Fanous said.

More people will now have access to the drug in more places, said Dr. Isaac Bogoch, an infectious diseases physician based at Toronto General Hospital.

"HIV pre-exposure prophylaxis is an excellent tool to prevent HIV infection and this would make it far more accessible to everybody in the province," Bogoch said. "I would anticipate programs like this would be very helpful in reducing rates of HIV."

People in Ontario could seek the drug from community health clinics, family medicine clinics and sexual health clinics, not just HIV physicians, he said.

There will be an application process and a deductible that will vary depending on a person's income.

Quebec's drug program covers PrEP for HIV treatment and prevention.

In British Columbia, discussions about the availability and accessibility of PrEP are underway.

In studies, use of the medication was associated with increased rates of nausea, vomiting and diarrhea and abdominal pain compared with a placebo. Kidney side-effects were also higher with the drug.

The medication does not protect against other sexually transmitted infections and prescribing physicians will continue to urge patients to use condoms.