Effects of Mexiletine on Colonic Transit in a Patient With Irritable Bowel Syndrome - Constipation (IBS-C)

Mayo Clinic

Status and phase: Completed; Phase 1

Conditions: IBS

Treatments: Drug: Mexiletine

Study type: Interventional

Funder types: Other

Identifiers

NCT01717404

12-006842

Details and patient eligibility

About

To understand if Mexiletine will restores normal colonic motility in a patient with irritable bowel syndrome - constipation (IBS-C) and a genetic mutation in SCN5A.

Full description

To understand if Mexiletine will restore normal colonic motility in a patient with a missense mutation in SCN5A, which encodes a voltage-sensitive sodium channel NaV1.5 as it is known to rescue certain expression defects of NaV1.5 in vitro.

Enrollment: 1 patient

Sex: Female

Ages: 60 to 70 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Established IBS diagnosis with a known A997T mutation in NaV1.5T

Exclusion criteria

• Normal 48-hour baseline transit study
• Current use of mexiletine
• Inability to stay in Rochester for 9 days for testing
• Known allergy to mexiletine
• Inability to complete daily diary
• Taking a medication known to affect myotonia, had a coexisting neuromuscular disease, or had another serious medical illness including second- or third-degree heart block, atrial flutter, atrial fibrillation, ventricular arrhythmia, history of cardiac arrhythmia requiring medication, congestive heart failure, symptomatic cardiomyopathy, or symptomatic coronary artery disease
• Inability to withdraw medications known to interact with mexiletine. Patient is currently not on any of these medications

Trial design

Primary purpose: Treatment

Allocation: N/A

Interventional model: Single Group Assignment

Masking: None (Open label)

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1 participants in 1 patient group

Mexiletine

Experimental group

Description:

6-day treatment period during which the medication will be taken orally with an initial dose of: 200 mg every 8 hours for 3 doses on day 3, increasing to 300 mg every 8 hours on days 4 and 5 (6 doses), and increasing further to 400 mg every 8 hours on days 6-8 if no telemetry changes and no dose limiting side effects

Treatment:

Drug: Mexiletine