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Theophyllines/Mexiletine (mono deleted 09/17/2014)

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:

The cause of the interaction is unknown.

What might happen:

Your blood levels of theophylline may increase and cause toxic effects.

What you should do about this interaction:

If you experience stomach pains, diarrhea, vomiting, nervousness, confusion, chest pain, or rapid heartbeat contact your doctor. You may need to check your blood level of theophylline and the dose of your medicine may need to be adjusted.Your healthcare professionals (e.g. doctor or pharmacist) may already be aware of this drug interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.


1.Katz A, Buskila D, Sukenik S. Oral mexiletine-theophylline interaction. Int J Cardiol 1987 Nov;17(2):227-8.

2.Stanley R, Comer T, Taylor JL, Saliba D. Mexiletine-theophylline interaction. Am J Med 1989 Jun;86(6 Pt 1):733-4.

3.Kessler KM, Interian A Jr, Cox M, Topaz O, De Marchena EJ, Myerburg RJ. Proarrhythmia related to a kinetic and dynamic interaction of mexiletine and theophylline. Am Heart J 1989 Apr;117(4):964-6.

4.Loi CM, Vestal RE. Effect of mexiletine on theophylline metabolism. Clin Pharmacol Ther 1990 Feb;47(2):130.

5.Ueno K, Miyai K, Seki T, Kawaguchi Y. Interaction between theophylline and mexiletine. DICP 1990 May;24(5):471-2.

6.Stoysich AM, Mohiuddin SM, Destache CJ, Nipper HC, Hilleman DE. Influence of mexiletine on the pharmacokinetics of theophylline in healthy volunteers. J Clin Pharmacol 1991 Apr;31(4):354-7.

7.Loi CM, Wei XX, Vestal RE. Inhibition of theophylline metabolism by mexiletine in young male and female nonsmokers. Clin Pharmacol Ther 1991 May;49(5):571-80.

8.Hurwitz A, Vacek JL, Botteron GW, Sztern MI, Hughes EM, Jayaraj A. Mexiletine effects on theophylline disposition. Clin Pharmacol Ther 1991 Sep;50(3):299-307.

9.Ueno K, Miyai K, Kato M, Kawaguchi Y, Suzuki T. Mechanism of interaction between theophylline and mexiletine. DICP 1991 Jul-Aug;25(7-8):727-30.

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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