Access and Utilization of New Antidepressant and Antipsychotic Medications. Utilization of Antipsychotics


In 1998, 51% of all Medicaid prescriptions for antipsychotics were for atypical antipsychotics. Expenditures on atypicals accounted for 89% of total spending on antipsychotics.

  • In 1998, Medicaid programs in 45 States analyzed paid for nearly 11 million prescriptions for antipsychotics.
    • Phenothiazines accounted for the largest share of antipsychotic prescriptions, with approximately 3.0 million prescriptions, or a 26% share.
    • Risperidone ranked second in number of prescriptions (2.8 million, 25%).
    • Olanzapine ranked third in number of prescriptions (2.2 million, 20%).
  • These 11 million prescriptions corresponded to expenditures of $1.3 billion.
    • Olanzapine accounted for the largest share of spending for antipsychotics at $536 million (42%).
    • Risperidone ranked second at $395 million (31%).
    • Clozapine accounted for the third largest share of expenditures, $172 million (14%).

The use of atypical antipsychotics in Medicaid has grown dramatically since 1995. Concomitantly, the use of antipsychotics as a class has grown by 20% since 1995.

  • Medicaid antipsychotic prescriptions rose from 9.2 million in 1995 to 11 million in 1998, an increase of nearly 20%.
    • It appears that the introduction of atypical antipsychotics did not merely replace older therapies, but instead expanded the market for use of these agents as a category.
      • Medicaid prescriptions for risperidone increased from just over 1 million in 1995 (12% of total) to nearly 2.8 million in 1997 (25% of total).
      • Medicaid prescriptions for olanzapine have risen from 43,000 prescriptions in 1996 (0.5%) to over 2.1 million prescriptions in 1998 (20%).
      • Prescriptions for oral haloperidol decreased from 2.1 million in 1995 (23%) to 1.6 million in 1998 (18%).
      • Prescriptions for phenothiazines decreased from 4.2 million in 1995 (47%) to just under 3 million in 1998 (27%).
    • This trend of increasing numbers of antipsychotic prescriptions may indicate that more patients are willing to use the newer agents.
    • This trend may also reflect increased use in the management of other diseases, such as the behavioral disturbances associated with dementia.

Expenditures on antipsychotics have vastly outpaced the growth in number of prescriptions.

  • Total Medicaid prescriptions for antipsychotics increased from 9.2 million in 1995 to nearly 11 million in 1998, an increase of 20%.
  • Total expenditures increased from $484 million in 1995 to $1.3 billion in 1998, an overall increase of 160%.

In several high-volume States (FL, IL, MA, MD, MI, PA) risperidone has become the most frequently prescribed class of antipsychotic, outpacing the national averages.

The uptake of newer antipsychotic agents into Medicaid immediately post-launch has been rapid.

  • From launch in the 4th quarter of 1996, olanzapine gained 8% market share within four full quarters of marketing.
    • At the end of the second full year on the market, olanzapine attained a market share of 16%.
    • The number of olanzapine prescriptions more than doubled in the second year on the market.
  • From the time of the launch of olanzapine, risperidone market share increased from 17% to 22%
    • During this same period the number of risperidone prescriptions increased nearly 50%.
  • The uptake of quetiapine has been slow relative to olanzapine.
    • This difference may largely be attributed to market timing and marketing savvy.