Alcohol and marijuana: Effects on epilepsy and use by patients with epilepsy

We review the safety of alcohol or marijuana use by patients with epilepsy. Alcohol intake in small amounts (one to two drinks per day) usually does n ot increase seizure frequency or significantly affect serum levels of antie pileptic drugs (AEDs). Adult patients with epilepsy should therefore be all owed to consume alcohol in limited amounts. However, exceptions may include patients with a history of alcohol or substance abuse, or those with a his tory of alcohol-related seizures. The most serious risk of seizures in conn ection with alcohol use is withdrawal. Alcohol withdrawal lowers the seizur e threshold, an effect that may be related to alcohol dose, rapidity of wit hdrawal, and chronicity of exposure, Individuals who chronically abuse alco hol are at significantly increased risk of developing seizures, which can o ccur during withdrawal or intoxication. Alcohol abuse predisposes to medica l and metabolic disorders that can lower the seizure threshold or cause sym ptoms that mimic seizures. Therefore, in evaluating a seizure in a patient who is inebriated or has abused alcohol, one must carefully investigate to determine the cause. Animal and human research on the effects of marijuana on seizure activity a re inconclusive, There are currently insufficient data to determine whether occasional or chronic marijuana use influences seizure frequency. Some evi dence suggests that marijuana and its active cannabinoids have antiepilepti c effects, but these may be specific to partial or tonic-clonic seizures. I n some animal models, marijuana or its constituents can lower the seizure t hreshold. Preliminary, uncontrolled clinical studies suggest that cannabidi ol may have antiepileptic effects in humans. Marijuana use can transiently impair short-term memory, and like alcohol use, may increase noncompliance with AEDs, Marijuana use or withdrawal could potentially trigger seizures i n susceptible patients.