US doctors issued nearly 200 million prescriptions for OxyContin, pictured, and other opioid painkiller last year, the American Medical Association said

US doctors reduced the number of prescriptions for opioid painkillers last year, continuing a five-year trend, in an effort to reverse a deadly drug abuse epidemic, a report released Thursday said.

The American Medical Association (AMA) found prescriptions for drugs including OxyContin and Vicodin declined nine percent in 2017, or about 19 million fewer prescriptions compared to a year earlier.

Opioid prescriptions are down by 55 million since 2013, a 22 percent reduction nationwide and a sign that "physicians and other health care professionals are increasingly judicious when prescribing opioids," Patrice Harris, chairwoman of the AMA's Opioid Task Force, said in a written statement.

There were still nearly 200 million painkiller in the US last year, the AMA report said.

In October, President Donald Trump described the opioid crisis as a national public health emergency.

Overdoses from prescription painkillers and heroin—a last-resort drug for opioid addicts—exploded over the last 20 years and kill 115 Americans a day, according to the National Institute on Drug Abuse, a federal agency.

Deaths continue to mount, and significant spikes in opioid fatalities were seen in many states between 2015 and 2016, according to the latest data from the Centers for Disease Control and Prevention.

Opioids were a factor in more than 42,000 deaths in 2016, and opioid overdose deaths were five times higher in 2016 than 1999, said the CDC.

The Chicago-based AMA, which represents the nation's doctors, also found a 42 percent jump in the number of physicians certified to treat opioid addiction with the drug buprenorphine. There are now more than 50,000 US doctors with the capability.

"What is needed now is a concerted effort to greatly expand access to high quality care for pain and for substance use disorders. Unless and until we do that, this epidemic will not end," Harris said.

US doctors have faced pressure as the overprescribing of mushroomed into a drug abuse epidemic. After patients are hooked on the painkillers, they often turn to the illicit drug market for more pills, the synthetic opioid fentanyl, or the street drug heroin.

Pop icon Prince and rocker Tom Petty are among the most high profile victims of the epidemic.

States and municipalities throughout the US have sued makers and distributors, among them Purdue Pharma, which in February announced it was discouraging its salespeople from touting OxyContin.