Slow release carbamazepine in treatment of poorly controlled seizures. Thirty three children with poorly controlled epilepsy, and six new patients, were treated with slow release carbamazepine. Twelve of the former had a reduction in the number of seizures of more than half, and 10 had fewer side effects. Three of the new patients stopped having seizures. Variations in plasma concentrations between doses was significantly less when patients took the slow release preparation (22%) compared with the standard preparation (41%). Slow release carbamazepine may improve the conditions of children whose seizures are poorly controlled. 