Prescriber utilization of dalfampridine extended release tablets in multiple sclerosis: a retrospective pharmacy and medical claims analysis

• Published in: Therapeutics and clinical risk management 2015-01, Vol.11, p.1-7
• Main Authors: Jara, Michele, Sidovar, Matthew F, Henney, 3rd, Herbert R
• Format: Article
• Language: English
• Subjects: Age; Codes; Comorbidity; Congenital diseases; Convulsions & seizures; Dalfampridine; disease-modifying therapy; Drug dosages; Drug therapy; Epidemiology; Family medical history; Forecasts and trends; Health attitudes; Health insurance; Kidney diseases; Multiple sclerosis; Original Research; Pain; Patients; Pharmacy; pharma­coepidemiology; Prescription writing; renal impairment; seizures
• ISSN: 1176-6336; 1178-203X; 1178-203X
• DOI: 10.2147/TCRM.S75837

This study aimed to characterize the prescribing of dalfampridine extended release (D-ER) 10 mg tablet treatment in people with multiple sclerosis (MS). A retrospective cohort study was performed using Medco pharmacy and medical claims. Medical claims were used to identify MS patients with more than one prescription for D-ER with 1 year of prior continuous enrollment (n=704). These patients were matched 2:1 on age, sex, and health insurance source with a comparison group of MS patients who were treatment naïve for D-ER (n=1,403). Categorical data were analyzed by χ (2) test; ordinal data by Wilcoxon rank sum test; and continuous data by Student's t-test. Most patients were women aged 45-64 years. In the year preceding D-ER initiation, the prevalence of seizure and renal impairment was numerically lower in the D-ER cohort relative to those who were D-ER naïve (seizure: 3.1% versus 4.7%, respectively; renal impairment: 4.3% versus 5.1%, respectively); however, prescriptions for antiepileptic drugs in the two cohorts were comparable. In the year preceding treatment initiation, 62% of the D-ER cohort was prescribed MS-specific disease-modifying therapies relative to 45% who were D-ER naïve. Seizure and renal impairment rates among D-ER-naïve patients were consistent with published literature, yet rates among those prescribed D-ER during the year preceding treatment initiation were slightly lower than rates among D-ER-naïve patients. Given that D-ER is contraindicated in patients with history of seizure or moderate or severe renal impairment, lower rates may indicate that risk-minimization strategies contributed to the lower prevalence.