Steven R. Henson was sentenced to life in prison for unlawfully prescribing and selling medication.

(CNN) A doctor in Kansas was sentenced to life in prison Friday for distributing prescription drugs that resulted in the death of a patient, federal officials said.

Wichita doctor Steven R. Henson, 57, was convicted in October after dozens of charges, including conspiracy to distribute prescription drugs outside the course of medical practice, presenting false patient records to investigators and money laundering, according to the Department of Justice.

Henson postdated prescriptions and wrote them without a medical need or legitimate exam in return for cash, federal officials said. In some instances, he prescribed opioid medications in dangerous amounts.

"There was ample evidence that Henson was prescribing opioid medications in amounts likely to lead to addiction, and in amounts so expensive that the patients would likely be forced by economic circumstances to support their addiction by selling some of the drugs to others," US District Judge J. Thomas Marten said.

One of his patients died

Prosecutors also presented evidence that his prescribing of alprazolam and methadone resulted in the 2015 death of one of his patients, Nick McGovern, CNN affiliate KOAM reported.

Some of McGovern's family members spoke in court, according to the station, saying this case should serve as an example to prevent it from happening to another family.

US Attorney Stephen McAllister sent a similar message.

"For any doctors, pharmacists or nurses who disregard their oath and distribute powerful drugs illegally to enrich themselves, the message today is that they will be prosecuted to the full extent allowed by federal law," McAllister said.

Crackdown on opioid epidemic

McAllister said his sentencing is part of a crackdown on the national opioid epidemic.

"We are dealing with an epidemic," McAllister said. "Nationwide, more than 70,000 Americans died in 2017 from drug overdoses. That is more than all the American casualties during the war in Vietnam."

Experts say the United States is in the throes of an opioid epidemic with more than 2 million people dependent on or abusing prescription pain pills and street drugs.

More than 130 people died every day from opioid-related drug overdoses in 2016 and 2017, according to the US Department of Health & Human Services.