Valproic acid therapeutic risks

PROCARBAZINE ANTIEPILEPTICS-CARBAMAZEPINE, PHENOBARBITAL PHENYTOIN, VALPROIC ACID T risk of hypersensitivity reactions in patients with brain tumours Strong correlation between the therapeutic antiepileptic level and the hypersensitivity reactions Consider using non-enzyme-inducing agents... 

Sodium valproate is converted to valproic acid in the intestine and the acid is absorbed. Absorption may be delayed by food or by enteric-coated tablets. Valproic acid has a low volume of distribution and high plasma protein binding. In the elderly there is a risk for increased free valproic acid concentrations requiring lower doses and plasma concentrations at the lower therapeutic range. However it should be realized that these plasma concentrations do not correlate very well with the therapeutic or toxic effects and careful observation for symptoms is mandatory. 

ETOPOSIDE ANTIEPILEPTICS - PHENYTOIN, PHENOBARBITAL Significantly i plasma concentrations of etoposide (clearance may be >170%) and considerable risk of loss of therapeutic efficacy Due to potent induction of the hepatic microsomal enzymes that metabolize etoposide Do not co-administer. Consider use of alternative antiepileptics that do not induce hepatic microsomal enzymes, e.g. valproic acid... 

PLATINUM COMPOUNDS ANTIEPILEPTICS -CARBAMAZEPINE, PHENYTOIN, VALPROIC ACID l plasma concentrations of antiepileptic, which t risk of seizures Due to impaired absorption of antiepileptic Monitor closely for seizure activity and warn patients and carers. Need to adjust dosage using parameters such as blood levels to ensure therapeutic levels... 

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