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CLIN. CHEM.37/1, 98-100 (1991)
Displacement of Phenytoin from Serum Protein Carriers by Antibiotics: Studies with Ceftriaxone, Nafcillin, and Sulfamethoxazole Amltava Dasgupta,1 David A. Dennen,1Roger Dean,2 and Ronald W. McLawhon1 Increased concentrations of free phenytoin in serum, attributable to the displacement of this anticonvulsant by other drugs, e.g., valproic acid and salicylic acid, have been reported. We observed in vitro and in vivo displace-
ment of phenytoin by the antibioticsceftriaxone, nafcillin, and sulfamethoxazole. In vitro studies demonstrated statistically significant (P
