CHLORAMPHENICOL AND PHENYTOIN
Serum phenytoin levels can be raised by the concurrent use of chloramphenicol. Also, evidence from children suggests that phenytoin may reduce or raise serum chloramphenicol levels. Fosphenytoin, a prodrug of phenytoin, may interact similarly.
Concurrent use should be avoided unless the effects can be closely monitored and appropriate phenytoin dosage reductions made as necessary. The use of a single prophylactic dose of phenytoin or fosphenytoin may be an exception to this. If both drugs are given, monitor for phenytoin toxicity (indicators include blurred vision, nystagmus, ataxia or drowsiness). Take phenytoin levels as necessary and adjust the dose accordingly. Also monitor for chloramphenicol efficacy and toxicity.
Concurrent use should be avoided unless the effects can be closely monitored and appropriate phenytoin dosage reductions made as necessary. The use of a single prophylactic dose of phenytoin or fosphenytoin may be an exception to this. If both drugs are given, monitor for phenytoin toxicity (indicators include blurred vision, nystagmus, ataxia or drowsiness). Take phenytoin levels as necessary and adjust the dose accordingly. Also monitor for chloramphenicol efficacy and toxicity.