Bioavailability of phenytoin: comparison between three preparations

Crossover studies, following single oral doses given to 19 healthy volunteers were conducted to compare the bioavailability of three phenytoin preparations: DANTOIN and IDANTOIN (Teva, Israel) and EPANUTIN (Parke-Davis, USA). The first has recently replaced the second as the only preparation available in Israel for alleged better bioavailability. The area under the serum concentration time curve (AUCo----48), however, did not significantly differ between preparations, indicating equivalent absorption of the three preparations. These results suggest that no overall adjustments are required when switching from one preparation to another.