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    Hydantoins/Select Neuromuscular Blocking Agents

    This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

    Medical warning:

    Moderate. These medicines may cause some risk when taken together. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

    How the interaction occurs:

    Phenytoin interferes with the action of the neuromuscular blocking agent.

    What might happen:

    There might be a decreased effectiveness of the neuromuscular blocking agent.

    What you should do about this interaction:

    Make sure your healthcare professionals (e.g. doctor or pharmacist) knows that you are taking medicine for seizures.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicines before checking with them first.


    1.Chen J Kim YD Dubois M Kammerer W Macnamara TE. The increased requirement of pancuronium in neurosurgical patients receiving Dilantin chronically. Anesthesiology Sept 1983;59(3):A288.

    2.Ornstein E, Matteo RS, Young WL, Diaz J. Resistance to metocurine-induced neuromuscular blockade in patients receiving phenytoin. Anesthesiology 1985 Sep;63(3):294-8.

    3.Liberman BA, Norman P, Hardy BG. Pancuronium-phenytoin interaction: a case of decreased duration of neuromuscular blockade. Int J Clin Pharmacol Ther Toxicol 1988 Aug;26(8):371-4.

    4.Hickey DR, Sangwan S, Bevan JC. Phenytoin-induced resistance to pancuronium. Use of atracurium infusion in management of a neurosurgical patient. Anaesthesia 1988 Sep;43(9):757-9.

    5.Ornstein E, Matteo RS, Schwartz AE, Silverberg PA, Young WL, Diaz J. The effect of phenytoin on the magnitude and duration of neuromuscular block following atracurium or vecuronium. Anesthesiology 1987 Aug;67(2):191-6.


    7.Gandhi IC, Jindal MN, Patel VK. Mechaism of neuromuscular blockade with some antiepileptic drugs. Arzneimittelforschung 1976 Feb;26(2):258-61.

    8.Soriano SG, Sullivan LJ, Venkatakrishnan K, Greenblatt DJ, Martyn JA. Pharmacokinetics and pharmacodynamics of vecuronium in children receiving phenytoin or carbamazepine for chronic anticonvulsant therapy. Br J Anaesth 2001 Feb;86(2):223-9.

    9.Gough JD, Smith A, Wise CC. Phenytoin-induced resistance to vecuronium. Anaesthesia 1989 Jun;44(6):520.

    10.Kumar CM, Lawler PG. Phenytoin-induced resistance to vecuronium. Anaesthesia 1989 Mar;44(3):263-4.

    Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, expect as may be authorized by the applicable terms of use.

    CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

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