Tonic-clonic seizures where generalised or focal (partial) onset is unclear
In some patients with tonic-clonic seizures, it is not clear from clinical, electroencephalogram or neuroimaging data whether the seizures are generalised or focal (partial) in onset. Use a ‘broad-spectrum’ antiepileptic drug effective against both types of seizure (eg sodium valproate, levetiracetam, lamotrigine, topiramate, clobazam). Carbamazepine and phenytoin are less likely to be effective, and may even aggravate the epilepsy, if the seizures are of generalised onset.
If sodium valproate is needed in females of childbearing potential, have an informed discussion with the patient (and parents or carers of patients) about its harms and benefits before starting therapy; see Planning for pregnancy in patients with epilepsy and Teratogenic and neurodevelopmental effects of antiepileptic drugs.
If considering starting sodium valproate in males of reproductive potential, see Sodium valproate use in males of reproductive potential; a discussion about the potential risk of neurodevelopmental disorders in children born to males taking sodium valproate may be appropriate.
For children, as first-line therapy, use:
sodium valproate , child older than 2 years, 5 mg/kg orally, twice daily for 5 days, then increase to 10 mg/kg twice daily; usual maintenance dose 10 to 20 mg/kg twice daily; maximum 2500 mg daily. epilepsy, tonic-clonic seizures of unclear onset sodium valproate
For females of childbearing potential who do not have reliable contraception, as first-line therapy, use:
levetiracetam 250 mg orally, twice daily for 1 week, then increase to initial target dose of 500 mg twice daily. If needed, increase by 500 mg daily up to 1500 mg twice daily. epilepsy, tonic-clonic seizures of unclear onset levetiracetam
For adult females who have reliable contraception or cannot have children, or adult males, as first-line therapy, use:
sodium valproate 500 mg orally, once daily for 1 week, then increase to initial target dose of 500 mg twice daily. If needed, increase up to 1500 mg twice daily. sodium valproate
If seizures persist, or if sodium valproate is not tolerated or indicated, refer the patient to an expert. Drugs that may be added or substituted include levetiracetam, lamotrigine, topiramate and clobazam.
If the patient's seizures are not controlled after trying two or three drug options, the patient should be referred to a specialist epilepsy centre.