Answer
Sulfamethoxazole + trimethoprim prolongs phenytoin’s half-life, potentially causing excessive phenytoin effects, so close monitoring of the patient’s condition and serum phenytoin levels is advisable when they are co-administered.
Sources for this answer
- Co-Trimoxazole 16 mg/ 80 mg per ml for Infusion.Aspen · emc · SmPC §4.5 Interaction with other medicinal products · Version 15Document updated
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