Evaluation of a Monthly Coverage Maximum (Drug-Specific Quantity Limit) on the 5-HT1 Agonists (Triptans) and Dihydroergotamine Nasal Spray

BACKGROUND: Ensuring the appropriate use of migraine therapies is an important consideration for care providers, patients, employers, and managed care organizations (MCOs) because of the high cost of treatment for this fairly prevalent disabling disease. A review of utilization of serotonin 5-HT1 receptor agonists (triptans) in an MCO determined that about 24% of the patients who received triptan therapy exceeded the manufacturer's recommendations regarding the maximum daily dose and safe treatment guidelines in a 30-day period. An initiative was designed to manage the coverage of migraine abortive therapies with the anticipated outcome of decreasing potential misuse or overuse of the medications. OBJECTIVES: The objective of this retrospective, observational study was to determine the impact of a monthly drug-specific milligram coverage maximum (quantity limit) on serotonin 5-HT1 receptor agonists (triptans) and dihydroergotamine (DHE) nasal spray on the utilization and costs of migraine care in an MCO with approximately 600,000 covered members. METHODS: A longitudinal, retrospective cohort analysis was conducted. All migraine-related services were analyzed, including outpatient medical visits, emergency department utilization, inpatient hospitalizations, and outpatient prescription drug use. The analysis was conducted using medical and pharmacy administrative claims. Analysis of data was performed for the period 12 months prior (October 1999 to September 2000) and 18 months post implementation of the monthly drug-specific milligram coverage maximum (October 2000 through March 2002). RESULTS: Imposition of a monthly coverage maximum for migraine-abortive therapies was associated with a 26.1% reduction in overall per- patient-per-month (PPPM) medical costs for migraine care, from $55.52 PPPM to $41.02 PPPM (P less than 0.01). Utilization of serotonin 5-HT1 receptor agonists and DHE nasal spray declined by 16.7%, from 0.18 prescriptions PPPM to 0.15 prescriptions PPPM (P=0.039), and direct drug costs declined by 28.8%, from $29.18 PPPM to $20.78 PPPM (P less than 0.001). Utilization and costs of outpatient and inpatient migraine-related medical services declined by 40% from $16.58 PPPM in the pre period to $9.94 PPPM in the post period (P less than 0.001). CONCLUSIONS: A monthly drug-specific milligram coverage maximum was associated with significant reduction in drug costs and utilization of serotonin 5-HT1 receptor agonists (triptans) and DHE nasal spray. Utilization and costs of migraine-related medical services also declined after implementation of the coverage maximum for triptans and DHE nasal spray. The monthly drug-specific milligram coverage maximum appeared to have been successful in managing utilization of triptans and DHE nasal spray, including reduction of overall costs of migraine-related medical services and direct drug costs.