Fluconazole-induced symptomatic phenytoin toxicity.
OBJECTIVE
To report two cases of fluconazole-induced symptomatic phenytoin toxicity and review literature related to this interaction.


METHODS
Case reports and review articles identified by a computerized (MEDLINE) and manual (Index Medicus) search.


RESULTS
Fluconazole is a broad-spectrum triazole antifungal agent primarily eliminated by renal mechanisms, although hepatic cytochrome P-450 inhibition and hepatotoxicity have been observed. We report two cases of fluconazole-induced symptomatic phenytoin toxicity. Both patients received high doses of the drug; one patient developed phenytoin toxicity only after long-term coadministration. Previously reported cases have occurred primarily with high-dose fluconazole and short-term coadministration.


CONCLUSIONS
Fluconazole can increase phenytoin serum concentrations leading to toxicity. Constant and continuous monitoring of serum phenytoin concentrations with fluconazole doses as low as 200 mg/d is warranted.
Cadle
R M
RM
Department of Veterans Affairs Medical Center (VAMC), Pharmacy Service, Houston, TX 77030.
Zenon
G J
GJ
Rodriguez-Barradas
M C
MC
Hamill
R J
RJ
D017088:AIDS-Related Opportunistic Infections / Q000150:complications / Q000188:drug therapy; D000328:Adult; D000818:Animals; D004347:Drug Interactions; D015725:Fluconazole / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010672:Phenytoin / Q000008:administration & dosage / Q000009:adverse effects* / Q000097:blood; D012640:Seizures / Q000150:complications / Q000188:drug therapy
D010672:Phenytoin; D015725:Fluconazole