Isoniazid may increase the serum concentration of ethosuximide, leading to toxicity. Antipsychotics, antidepressants, MAOIs, and mefloquine may antagonise anticonvulsant effects of ethosuximide. Plasma conc of ethosuximide may be reduced by carbamazepine, phenobarbital, phenytoin, and primidone; and affected by valproate. Chloroquine or hydroxychloroquine may increase risk of convulsions. Isoniazid.
Blood toxicities and disorders; headache, fatigue, lethargy, drowsiness, dizziness, ataxia, hiccup and mild euphoria; more rarely, psychotic states, rashes, hepatic and renal changes, and haematological disorders. SLE, erythema multiforme. Gum hypertrophy, swelling of tongue, irritability, hyperactivity, sleep disturbances, night terrors, inability to concentrate, aggressiveness, increased libido, myopia, vag bleeding.
Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.
Hepatic or renal impairment, porphyria. Complete blood cell count, liver function tests, and urinalysis should be performed periodically. May increase the risk of grand mal seizures when used alone in mixed types of epilepsy. Avoid sudden withdrawal. May impair ability to drive or operate machinery.
