CARRIZO SPRINGS, Texas (ValleyCentral) — A Carrizo Springs doctor was sentenced to federal prison after unlawfully prescribing large amounts of controlled substances, including lethal combinations.

Dr. Alfonso Luevano, 53, was sentenced to 121 months in prison Thursday on charges of unlawful distribution of a controlled substance and Medicaid fraud, the U.S. Attorneys Office Western District announced in a news release.

Along with Luevano, members of his staff were also sentenced, including: physician assistant Richard Marquez, 62; nurse practitioners Sara Barker, 47, and Rafael Santana, 49; and office manager Ofelia Martinez, 53, authorities said.

Marquez was sentenced to two years in prison, Barker was sentenced to 18 months and Santana received a one-year sentence. Martinez was sentenced to 30 months in prison.

According to the release, Luevano prescribed “large amounts” of controlled substances, primarily made up of Schedule II opioids with “little or no medical examination.”

Authorities stated that Luevano and his staff issued at least 20,000 prescriptions between March 2016 and March 2018, with half of the prescriptions being hydrocodone.

“The investigation also revealed several instances of Luevano prescribing patients a potentially lethal combination of an opioid, a benzodiazepine and a muscle relaxer,” the release stated.

The prescriptions resulted in multiple patient overdoses, including two that were fatal, the U.S. Attorney’s Office stated.

Barker, Santana and Marquez pleaded guilty to “facilitating the prescriptions,” by seeing the patients and directing the pre-signed prescription pads be filled, the release stated.

Martinez signed a plea agreement, stating that she overbilled the Texas Medicaid program by billing them as if Luevano performed appointments, when they were performed by the mid-level practitioners instead. She was ordered to pay $127,421 in restitution.

“Luevano’s excessive prescribing of opioids, often times without the benefit of a medical examination, had a total disregard to patient safety and the law,” said Special Agent in Charge Daniel C. Comeaux of the Drug Enforcement Administration’s Houston Division.  “In just one year, Luevano illegally prescribed thousands of opioids in our communities. Relentless efforts by our Diversion investigators, Special Agents and prosecutors ended Luevano’s greed that has contributed to the ongoing opioid epidemic.  DEA will continue to bring to justice those who misuse their prescribing authority for personal gains.”