Primidone, estimation

K20. Kupferberg, H. J., Quarrtitative estimation of diphenylhydantoin, primidone and phenobarbital in plasma by gas-liquid chromatography. Clin. Chim. Acta 29, 283-288 (1970). 

True hypersensitivity reactions to phenytoin are related to the "aromatic" anticonvulsants. Thus, in patients in whom a reaction is suspected, other arene anticonvulsants such as carbamazepine, oxcarbazepine, phenobarbital, or primidone should be avoided, as there is a high rate of cross-reactivity (estimated as high as 80%). Valproic acid is an agent that can be safely used as an alternative anticonvulsant in such patients. 

A 3-year-old child taking both phenobarbital and phenytoin required quinidine 300 mg every 4 hours to achieve therapeutic serum quinidine levels, and had an estimated quinidine half-life of only 1.4 hours. Difficulty in achieving adequate serum quinidine levels was also reported in a woman taking phenytoin and primidone. Her quinidine half-life was... 

Quantitative Estimation of Diphenyl-hydantoin. Primidone, and Fheno-barbital in Plasma by Gas-Liquid Chromatography... 

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