PHENYTOIN AND PROTON PUMP INHIBITORS
A study found that omeprazole 20 mg daily did not affect phenytoin levels, whereas earlier studies suggested that phenytoin levels might be modestly raised by omeprazole 40 mg daily. A study with esomeprazole also suggests that it may cause a minor rise in phenytoin levels. Lansoprazole does not normally interact with phenytoin, but an isolated case report of toxicity is tentatively attributed to an interaction. Fosphenytoin, a prodrug of phenytoin, may interact similarly with these proton pump inhibitors.
This interaction is unlikely to be generally significant, but bear it in mind in case of an unexpected response to treatment. Indicators of phenytoin toxicity include blurred vision, nystagmus, ataxia or drowsiness. However, note that the manu- facturers of esomeprazole recommend monitoring phenytoin levels.
This interaction is unlikely to be generally significant, but bear it in mind in case of an unexpected response to treatment. Indicators of phenytoin toxicity include blurred vision, nystagmus, ataxia or drowsiness. However, note that the manu- facturers of esomeprazole recommend monitoring phenytoin levels.