A doctor wrote over 20,000 prescriptions for opioids, prosecutors say. Five people died.

A doctor in Alaska, who authorities say wrote over 20,000 opioid prescriptions in six years, was sentenced to nearly three years in prison after he illegally prescribed drugs resulting in the death of five patients, prosecutors say.

David Chisholm, 64, pleaded guilty in June to unlawful dispensing and distribution of a controlled substance, which can be charged as a felony, according to the U.S. Attorney's Office for the District of Alaska. Chisholm was required to surrender his state medical license, was fined $25,000 and sentenced to 34 months in jail.

Chisholm is accused of illegally prescribing his patients thousands of opioid pills, including oxycodone, methadone, hydrocodone, morphine and fentanyl at his medical practice at the Camelot Family Health Clinic in Wasilla, Alaska.

In less than six years, Chisholm wrote over 20,500 prescriptions to about 350 patients, including more than 7,500 prescriptions for oxycodone, 3,600 for methadone and 1,300 for hydrocodone, the U.S. Attorney's Office for the District of Alaska said in a statement. He also prescribed combinations of drugs that increase the likelihood of drug abuse and overdose, the office said.

As part of his plea agreement, Chisholm acknowledged the prescriptions were a significant contributing factor in the overdose deaths of five patients between 2016 and 2018, according to the statement.

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An undercover investigation found that Chisholm regularly distributed controlled substances without doing medical exams and without "legitimate medical purpose," the U.S. Attorney's Office said. He also didn't develop pain management plans for patients and kept "virtually non-existent" records."

Prosecutors also accused Chisholm of writing prescriptions under multiple variations of patients' names, allowing them to avoid raising red flags when refilling their drugs. At one point, Walmart refused to continue filling prescriptions he wrote. In response, he told his staff to go to other pharmacies, the U.S. Attorney's Office said.

"Dr. Chisholm’s reckless conduct reflects a shocking disregard for the welfare of his patients," U.S. Attorney John E. Kuhn Jr. of the District of Alaska said in a statement. "Nothing can excuse his opioid prescribing practices in light of what is today universally understood about the risks of opioid use disorder and opioid overdose."

Record numbers of Americans are dying from drug overdose. Between April 2020 and April 2021, more than 100,000 people died of drug overdose, mostly from synthetic opioids such as fentanyl, according to the Centers for Disease Control and Prevention. That number is a 28.5% increase from the year before. Estimated overdose deaths from opioids increased to over 75,000 from about 56,000 the year before.

The Substance Abuse and Mental Health Services Administration offers a free, confidential, 24-hour helpline for people of families facing substance use disorders at 1-800-662-4357. The organization also has an online opioid overdose prevention toolkit and a directory for treatment programs.

Contact News Now Reporter Christine Fernando at cfernando@usatoday.com or follow her on Twitter at @christinetfern.'Dramatic decreases' in teen drug use: Drug and alcohol use among US teens saw record decline in 2021, survey finds

This article originally appeared on USA TODAY: Alaska doctor illegally prescribed opioids, causing 5 deaths