A Chicago psychiatrist who prescribed the antipsychotic clozapine to thousands of nursing home residents in exchange for kickbacks was sentenced to 9 months in prison on Friday.

Michael Reinstein received close to $600,000 from pharmaceutical companies in exchange for prescribing Clozaril (the brand-name version of clozapine) to thousands of elderly hospital and nursing home patients in the Chicago area.  

At one point in the early 2000s, Reinstein was the largest prescriber of clozapine to Medicaid recipients in the country — more than all of the doctors in Texas combined, according to ProPublica. In exchange for prescribing Clozaril, and later the drug’s generic version, Reinstein received consulting fees, meals, sports tickets and vacations.

Clozapine is used to treat schizophrenia but is known to carry serious side effects for seniors, including a decrease of white blood cells, seizures and heart inflammation.

In addition to the prison time, Reinstein must repay the government $592,000 and serve 120 hours of community service.

His medical license was suspended in connection with the kickback case in 2014.

Reinstein previously paid $3.79 million to settle a government-filed lawsuit that claimed he submitted at least 140,000 false Medicare and Medicaid claims for the drug.