Mexiletine Hydrochloride and Theo-Dur

In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.

Mexiletine may significantly increase the blood levels of theophylline, which may lead to potentially serious and life-threatening side effects. Talk to your doctor if you have any questions or concerns. Your doctor may be able to prescribe alternatives that do not interact, or you may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Contact your doctor if you develop nausea, vomiting, diarrhea, loss of appetite, headache, tremor, confusion, restlessness, insomnia, seizures, heart palpitations, and/or irregular heartbeat, as these may be signs and symptoms of excessive theophylline levels. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

MONITOR CLOSELY: Coadministration with mexiletine may increase the serum concentrations of theophylline. The proposed mechanism is inhibition of the CYP450 1A2-mediated metabolism of theophylline by mexiletine. Pharmacokinetic studies have shown that mexiletine increases theophylline concentrations by approximately 50% to 100%, although greater increases of up to 3-fold accompanied by symptoms of toxicity have been described in a few case reports. Discontinuation of mexiletine or dosage reductions of theophylline by one-half to two-thirds were required in some cases.

MANAGEMENT: Caution is advised when theophylline is used with mexiletine. Close monitoring of serum theophylline levels is recommended, particularly following the addition, discontinuation or change of dosage of mexiletine, and the theophylline dosage adjusted accordingly. Patients should be advised to notify their physician if they experience signs of theophylline toxicity such as nausea, vomiting, diarrhea, headache, restlessness, insomnia, seizures, palpitations, and cardiac arrhythmia.

Mexiletine Hydrochloride

Generic Name: mexiletine

Brand name: Mexitil

Synonyms: Mexiletine

What is Mexiletine Hydrochloride?

Theo-Dur

Generic Name: theophylline

Brand name: Elixophyllin, Theo-24, Respbid, T-Phyl, Aerolate III, Slo-Bid Gyrocaps, Slo-Phyllin, Theobid, Theo-Dur, Theolair, Theovent, Bronkodyl, Theo-X, Theo-Time, Theochron, Slo-Phyllin 125, Theoclear LA-130, Aerolate JR, Theolair-SR, Theoclear LA-260, Quibron-T, Quibron-T/SR, Uniphyl, Uni-Dur, Aerolate SR, Slo-Phyllin 80, Theoclear-80, Theo-Dur Sprinkles, Theosol-80, Asmalix, Aquaphyllin, Truxophyllin, Slo-Phyllin 250, TheoCap

Synonyms: Theo-Dur (Oral)

What is Theo-Dur?