Abstracts

While prevalence of antiepileptic drug/non-antiepileptic drug (AED) concomitant medication and interaction is described for elderly, few data exist regarding gender and age patterns of potentially clinically important PK interactions. Specifically, we report on prevalence of polytherapy across age and gender groups, but also describe patterns of cardiovascular and psychotropic drug., A retrospective cohort study was conducted in epilepsy patients using a US claims database (1/2001-12/2004). Patients were sub-grouped: enzyme inducing AEDs (EIAEDs) or non-inducing (NEIAEDs).Usage of concomitant medications taken during the six month after AED initiation was compared using Chi-squared tests for: Young Adults (YA)(18-34yo), Adults (A)(35-54), Older Adults (OA)(55-64), Young Old (YO)(65-74), Middle Old (MO)(75-84), Elderly (E)(85+)., A total of 9526 patients with epilepsy were identified: 6134 females and 3392 males; 5970 receiving EIAED and 3556 NEIAED. Overall, polytherapy was common and increased with age (table 1). Females are more likely to receive a concomitant medication regardless of AED use: EIAED (86%vs76%,p[lt]0.001); NEIAED (86%vs79%,p[lt]0.001). Compared to general population data (Sloan Survey, 2004), epilepsy patients in every age and gender group appeared to be significantly more likely to be receiving at least 5 concomitant medications: 23 % of men and 39% of women with epilepsy age18-44 were on 5+ medications vs 2-3% in general population. In men and women age 45-64, this figure was 47-60% vs 10-15% in general population. Most frequent comedications are antipsychotics (YA:10%-YO:19%), SSRI antidepressants (YA:20%-YO:28 %), TCA antidepressants (YA:7%-OA:11%), Calcium channel blockers (YA:3%-E:35%) and statins (YA:2%-YO:41 %). Antidepressants are more common for females (SSRI:25%vs16%;TCA:9%vs5%).[table1], Concomitant drug use occurs across all age groups, not simply the elderly. Not surprisingly, the occurrence of polypharmacy with potentially interacting medication appears to steadily increase with age. Discrimination in AED selection based upon potential PK interactions was not seen. While no specific gender differences were seen with cardiovascular medications, differing patterns of gender specific psychotropic drug use may exist. These findings suggest that clinicians must be mindful of polypharmacy and potential non-AED interactions in all age groups, not only elderly patients., (Supported by UCB INC.)