Abstracts

Rationale: Adverse cognitive effects (ACEs) occur in many patients taking antiepileptic drugs (AEDs). Cross-sensitivity in AEDs can be defined as the extent to which the presence of ACE to a specific AED affects the chance of having ACE to other AED(s). The cross-sensitivity of ACEs among AEDs is not known. Our study aims to determine rates of cross-sensitivity of ACEs among commonly used antiepileptic drugs AEDs in adult patients ( 16) with epilepsy.Methods: As part of the Columbia and Yale AED database, we conducted a retrospective review of patient background, medical history, AED use, AED-attributed side effects, and side effect intolerability leading to dose change for 2915 adult patients. ACEs included were language problems/aphasia/anomia/word-finding trouble, poor concentration, poor memory, psychomotor slowing, cognitive slowing, and confusion/disorientation. The incidence of intolerability to ACE was determined for carbamazepine (CBZ), clobazam (CLB), felbamate (FBM), gabapentin (GBP), lacosamide (LCM), levetiracetam (LEV), lamotrigine (LTG), oxcarbazepine (OXC), phenobarbital (PB), pregabalin (PGB), phenytoin (PHT), primidone (PRM), tiagabine (TGB), topiramate (TPM), vigabatrin (VGB), valproic acid (VPA), and zonisamide (ZNS). We compared the rates of intolerability to ACE for each AED in patients with vs without intolerability to ACE to 1) another specific AED; 2) any other AED. Statistical significance was set at p < 0.01 and trend 0.01 < p < 0.05. Multivariate analysis of 53 variables showed that previous psychiatric condition, complex partial seizure, prior brain surgery, and parietal lobe epilepsy were significant non-AED predictors of intolerability to ACE. These predictors were adjusted for in all cross-sensitivity analyses.Results: 16.9% (488/2884) of patients had intolerability to ACE attributed to at least one AED; 3.5% (100/2884) had intolerability to two or more AEDs. In general, having intolerability to ACE to any drug led to a tripling of the risk of intolerability to ACE to another drug (OR: 3.08, 95% CI: 2.54 - 3.73). The only two drugs with significant specific cross-sensitivity were LTG and PHT. Of patients who had intolerability to LTG and also took PHT, 28.6% (10/35) had intolerability to PHT (abbreviated as LTG ->