Brand and Other Names:
- Classes: Antidysrhythmics, Ib
Dosing & Uses
Dosage Forms & Strengths
Ventricular Arrhythmias (Life-Threatening)
200-300 mg PO TID
May increase to 400 mg q8hr
No more than 1200 mg/day
Take with food or antacid
Therapeutic range: 0.5-2 mg/L
Organ Transplant Rejection (Orphan)
Prevention of acute and chronic rejection in patients who have received solid organ transplants
Orphan indication sponsor
- James W Williams, MD; Rush-Presbyterian-St. Luke's Medical Ctr, Dept o, 1653 West Congress Parkway; Chicago, IL 60612-3833
Treatment of nondystrophic myotonia
Orphan indication sponsor
- University of Rochester Medical Center; 1351 Mt. Hope Ave, Suite 203; Rochester, NY 14620
Clcr<10 mL/min: 50-75% of normal dose
25-30% of normal dose
Other Indications & Uses
Life-threatening ventr arrhythmias
Off-label: Prophylaxis of vent. arrhythmias in acute phase MI (no change in mortality)
Not FDA approved
Usual dose for arrhythmias: 2.5-5 mg/kg PO q8hr
Serious - Use Alternative
Significant - Monitor Closely
Coordination difficulties (10%)
Blurred vision (6%)
Frequency Not Defined
Exacerbation of CHF
Systemic lupus erythematosus
Black Box Warnings
National Heart, Lung, and Blood Institute's Cardiac Arrhythmia Suppression Trial (CAST): Excessive mortality or nonfatal cardiac arrest (7.7%) shown with encainide or flecainide compared with placebo (3%)
CAST was a long-term, multicenter, randomized, double-blind study in patients with asymptomatic non-life-threatening ventricular arrhythmias who had a myocardial infarction (MI) >6 days but <2 yr previously
Average duration of treatment w/ encainide or flecainide in CAST was 10 months
Applicability of CAST results to other populations (eg, patients without recent MI) is uncertain
Reserve use of Class IC antiarrhythmics for life-threatening ventricular arrhythmias: Considering the known proarrhythmic properties of mexiletine & lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, mexiletine use, as well as other antiarrhythmic agents, should be reserved for patients with life-threatening ventricular arrhythmias
Hypersensitivity to mexiletine
Cardiogenic shock, 2°/3° AV block w/o pacemaker
CHF, hypotension, history of seizures
Use in less severe arrhythmias not recommended; avoid in Tx of asymptomatic ventricular premature contractions
Hepatic dz, seizure disorders, pregnancy
Good for automatic and reentrant arrhythmias, not PSVT's
Pregnancy & Lactation
Pregnancy Category: C
Lactation: enters breast milk at concs comparable to maternal plasma (AAP Committee states compatible w/ nursing)
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Half-Life: 6-17 hr
Peak Plasma Time: 1-4 hr (PO)
Therapeutic range: 0.5-2 mcg/mL
Toxicity range: >2 mcg/mL
Protein Bound: 50-70%
Vd: 5-9 L/kg
Metabolism: in liver to form parahydroxymexiletine & 2-hydroxymexiletine mainly by hepatic P450 enzyme CYP2D6 & partially by CYP1A2
Metabolites: parahydroxymexiletine & 2-hydroxymexiletine (inactive)
Excretion: urine 8-15%
Dialyzable: HD: no; PD: no
Mechanism of Action
Class 1B antidysrhythmic; combines with fast Na channels & thereby inhibits recovery after repolarization resulting in decreasing myocardial excitsbility & conduction velocity
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.
|1||This drug is available at the lowest co-pay. Most commonly, these are generic drugs.|
|2||This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.|
|3||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.|
|4||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|5||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|6||This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.|
|NC||NOT COVERED – Drugs that are not covered by the plan.|
Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
Select a box to add or remove a plan.
Select a class to view formulary status for similar drugs