ISSN:
1432-1041
Keywords:
Valproate
;
Phenytoin
;
drug interaction
;
slow-release tablet
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Changes in phenytoin concentrations caused by switching valproate formulations with different absorption rates were retrospectively investigated in eleven epileptic patients receiving treatment with both drugs. Total plasma phenytoin concentrations were measured before and after a standard tablet of valproate was replaced by the same dose as a slow-release tablet. The mean plasma phenytoin level rose significantly from 14.4 to 18.7 μg·ml−1. Nine of eleven patients had markedly increased phenytoin levels (by 21 to 72%), and two developed toxic symptoms. The results indicate that changing valproate formulations can cause major alterations in the plasma concentration of co-administered phenytoin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00202174
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