Comparison and predictors of rash associated with 15 antiepileptic drugs.
OBJECTIVE
To determine predictors and relative incidence of antiepileptic drug (AED)-related rash in patients taking all common AEDs.


METHODS
We reviewed 1,890 outpatients. Eighty-one variables were tested as potential predictors of rash. We compared the rate of rash attributed to each AED (AED rash) with the average rate of rash attributed to the other AEDs in all adults (aged > or =16 years; n = 1,649) when taking carbamazepine (CBZ), clobazam (CLB), felbamate (FBM), gabapentin (GBP), lamotrigine (LTG), levetiracetam (LEV), oxcarbazepine (OXC), phenobarbital (PB), phenytoin (PHT), primidone (PRM), tiagabine (TGB), topiramate (TPM), vigabatrin (VGB), valproate (VPA), or zonisamide (ZNS). We repeated this analysis for patients with and without the identified nondrug predictors of AED rash.


RESULTS
The average rate of AED rash was 2.8%. The only nondrug predictor significant in multivariate analysis was occurrence of another AED rash (odds ratio 3.1, 95% CI 1.8 to 5.1; p < 0.0001); the rate of rash in this subgroup was 8.8%, vs 1.7% in those without another AED rash. Higher AED rash rates were seen with PHT (5.9% overall, p = 0.0008; 25.0% in those with another AED rash, p = 0.001), LTG (4.8%, p = 0.00095; 14.4%, p = 0.025), and CBZ (3.7%, not significant; 16.5%, p = 0.01). Lower rates were seen with LEV (0.6% overall; p = 0.00042), GBP (0.3%, p = 0.00035), and VPA (0.7%, p = 0.01). Rash rates were also low (<1% overall) with FBM, PRM, TPM, and VGB (not significant). These AED differences remained similar in patients with and without other AED rashes. There were four cases of Stevens-Johnson syndrome involving four AEDs.


CONCLUSIONS
The rate of an antiepileptic drug (AED) rash is approximately five times greater in patients with another AED rash (8.8%) vs those without (1.7%). Rash rates were highest with phenytoin, lamotrigine, and carbamazepine and low (<1%) with several AEDs.
Arif
H
H
Comprehensive Epilepsy Center, Department of Neurology, Columbia University, New York, NY 10032, USA.
Buchsbaum
R
R
Weintraub
D
D
Koyfman
S
S
Salas-Humara
C
C
Bazil
C W
CW
Resor
S R
SR
Hirsch
L J
LJ
D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D015897:Comorbidity; D003875:Drug Eruptions / Q000453:epidemiology* / Q000209:etiology; D004342:Drug Hypersensitivity / Q000453:epidemiology; D004827:Epilepsy / Q000188:drug therapy; D005076:Exanthema / Q000139:chemically induced*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012306:Risk; D013262:Stevens-Johnson Syndrome / Q000139:chemically induced
D000927:Anticonvulsants