AZOLES AND PHENYTOIN - POSACONAZOLE OR VORICONAZOLE

Phenytoin decreases the levels of voriconazole and posaconazole by about 50%. Also, voriconazole increases the maximum serum levels and AUC of phenytoin by 67% and 81%, respectively. Potentially clinically significant increases in phenytoin levels have been reported in some patients taking posaconazole. Fosphenytoin, a prodrug of phenytoin, may interact similarly.
Concurrent use should be avoided unless the benefits outweigh the risks. If both drugs are used be alert for evidence of phenytoin toxicity (blurred vision,
nystagmus, ataxia or drowsiness) and, if necessary, adjust the dose based on
phenytoin levels. The dose of oral voriconazole should be increased from 200 to 400 mg twice daily, or from 100 mg to 200 mg twice daily in patients who weigh less than 40 kg, and intravenous voriconazole should be increased from 4 to 5 mg/kg twice daily. Similarly, consideration should be given to increasing the posaconazole dose.
(20)
This site is intended for general information only. The information provided on this site does not constitute medical advice and should not be relied upon. You should not act or refrain from acting on any legal or medical matter based on the content of this site.
© 2006-2025 medpill.info Last Updated On: 06/09/2025 (0)
×
Wait 20 seconds...!!!