An Al-Jazeera America investigation airing Saturday night spotlights heroin use and prescription drug addiction in Portland and Bangor.

The episode of the television network’s series “Fault Lines” looks at the use of opioid painkillers and links to heroin use. Maine has one of the highest rates of prescription painkiller addiction in the country.

The producer of the piece, Sam Black, is from Portland.

The half-hour episode, “Opioid Wars,” will air at 7 p.m. Saturday. Al-Jazeera America is on Channel 210 on Time Warner Cable in the Portland market.

Reporters followed ambulance crews, which, the report says, respond to an opioid-related call almost every day. The episode also focuses on why the U.S. Food and Drug Administration last year approved another opioid painkiller, Zohydro, in addition to others on the market, such as OxyContin and Vicodin, that have led to addictions. Four out of five heroin users have reported that they previously abused prescription opioids, the report said.

The episode also will air at 10 p.m. Saturday and 2 a.m. Sunday.