OBJECTIVES: To examine trends in the utilization, pharmacy reimbursement, and prices of flu antiviral medications in the US Medicaid-covered population

METHODS: A retrospective drug utilization study was conducted using the national summary files for outpatient drug utilization and expenditure for flu anti-viral medications from the Centers for Medicare & Medicaid Services from January 2000 through June 2017, to examine the annual trends of the number of prescriptions, reimbursement expenditures, and the prices of flu antiviral medications. The study drugs included Oseltamivir phosphate (Tamiflu) and zanamivir (Relenza).

RESULTS: The total number of prescriptions for flu anti-viral medications increased rapidly from 49,512 in 2000 to 1,134,353 in 2017. During the same period, the total pharmacy reimbursement for flu anti-viral medications in Medicaid increased from approximately $2.4 million in 2000 to approximately $244million in 2017. Tamiflu had a dominant market share with an average of 97.5% throughout the study period when compared to Relenza. The price per Tamiflu prescription drug increased over time, ranging from approximately $53 in 2000 to $213 in 2017, while Relenza increased from $42 to $63 in the same period.

CONCLUSIONS: Medicaid expenditures and the number of prescriptions for flu anti-viral medications abruptly increased over the study period between 2000 and 2017. Increases in flu anti-viral drug expenditures from 2000 to 2017 were primarily due to the rising utilization of flu antiviral medications.