Dosing & Uses
Dosage Forms & Strengths
capsule
- 150mg
- 200mg
- 250mg
Ventricular Arrhythmias (Life-Threatening)
Initial: 200 mg PO q8hr; may load with 400 mg followed by 200 mg PO q8hr if necessary for rapid control of ventricular arrhythmia
Dose range: 200-300 mg PO q8hr
May increase to 400 mg q8hr; not to exceed 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
Myotonia (Orphan)
Treatment of nondystrophic myotonia
Orphan indication sponsor
- University of Rochester Medical Center; 1351 Mt. Hope Ave, Suite 203; Rochester, NY 14620
Renal Impairment
CrCl<10 mL/min: 50-75% of normal dose
Hepatic Impairment
Liver impairment or CHF: 25-30% of normal dose
Not FDA approved
Usual dose for arrhythmias: 2.5-5 mg/kg PO q8hr
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (2)
- dofetilide
mexiletine, dofetilide. Either increases effects of the other by pharmacodynamic synergism. Contraindicated. Additive cardiac effects.
- fezolinetant
mexiletine will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors
Serious - Use Alternative (16)
- abametapir
abametapir will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP1A2 substrates. If not feasible, avoid use of abametapir.
- alosetron
mexiletine will increase the level or effect of alosetron by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated.
- artemether/lumefantrine
artemether/lumefantrine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- duloxetine
mexiletine will increase the level or effect of duloxetine by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated.
- fluoxetine
fluoxetine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- fluvoxamine
fluvoxamine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.
- givosiran
givosiran will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP1A2 substrates with givosiran. If unavoidable, decrease the CYP1A2 substrate dosage in accordance with approved product labeling.
- leniolisib
leniolisib will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Avoid leniolisib with CYP1A2 substrates that have a narrow therapeutic index
- lumefantrine
lumefantrine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- paroxetine
paroxetine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- pefloxacin
pefloxacin will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.
- pimozide
mexiletine, pimozide. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of prolonged QTc interval.
- pirfenidone
mexiletine will increase the level or effect of pirfenidone by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug. Use of strong CYP1A2 inhibitors should be discontinued before initiating pirfenidone and avoided during treatment; if strong CYP1A2 inhibitors are the only drug of choice, dosage reductions are recommended
- pomalidomide
mexiletine increases levels of pomalidomide by affecting hepatic enzyme CYP1A2 metabolism. Avoid or Use Alternate Drug.
- quinidine
quinidine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Avoid or Use Alternate Drug.
- tizanidine
mexiletine will increase the level or effect of tizanidine by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated.
Monitor Closely (91)
- abiraterone
abiraterone increases levels of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Avoid coadministration of abiraterone with substrates of CYP2D6. If alternative therapy cannot be used, exercise caution and consider a dose reduction of the CYP2D6 substrate.
- acetazolamide
acetazolamide will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- aluminum hydroxide
aluminum hydroxide will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- amiodarone
amiodarone will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- amobarbital
amobarbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- armodafinil
armodafinil will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- asenapine
asenapine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- bendamustine
mexiletine increases levels of bendamustine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Decreased conversion of bendamustine to active metabolites. Concentration of active metabolites of bendamustine may be decreased.
- bupropion
bupropion will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- butabarbital
butabarbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- butalbital
butalbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- calcium carbonate
calcium carbonate will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- cannabidiol
cannabidiol, mexiletine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Owing to the potential for both CYP1A2 induction and inhibition with the coadministration of CYP1A2 substrates and cannabidiol, consider reducing dosage adjustment of CYP1A2 substrates as clinically appropriate.
- carbamazepine
carbamazepine will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- celecoxib
celecoxib will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- chloroquine
chloroquine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- cigarette smoking
cigarette smoking will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- cimetidine
cimetidine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
cimetidine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. - ciprofloxacin
ciprofloxacin will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Mexiletine concentrations may be elevated and may produce an increase in therapeutic and adverse reactions.
- clobazam
clobazam will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Lower doses of drugs metabolized by CYP2D6 may be required when used concomitantly.
- clomipramine
mexiletine will increase the level or effect of clomipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- clozapine
mexiletine will increase the level or effect of clozapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- cobicistat
cobicistat will increase the level or effect of mexiletine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clinical monitoring is recommended upon coadministration with antiarrhythmics.
- darifenacin
darifenacin will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- darunavir
darunavir will increase the level or effect of mexiletine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Clinical monitoring is recommended upon coadministration with antiarrhythmics.
- deferasirox
deferasirox will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- desvenlafaxine
desvenlafaxine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Desvenlafaxine inhibits CYP2D6; with higher desvenlafaxine doses (ie, 400 mg) decrease the CYP2D6 substrate dose by up to 50%; no dosage adjustment needed with desvenlafaxine doses <100 mg
- diphenhydramine
diphenhydramine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- dronedarone
dronedarone will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- duloxetine
duloxetine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- eltrombopag
mexiletine will increase the level or effect of eltrombopag by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- eluxadoline
mexiletine increases levels of eluxadoline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. As a precautionary measure due to incomplete information on the metabolism of eluxadoline, use caution when coadministered with strong CYP1A2 inhibitors.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP2D6 inhibitor; caution with CYP2D6 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
- erythromycin base
erythromycin base will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- erythromycin ethylsuccinate
erythromycin ethylsuccinate will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- erythromycin lactobionate
erythromycin lactobionate will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- erythromycin stearate
erythromycin stearate will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- ethinylestradiol
ethinylestradiol will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- ethotoin
ethotoin decreases levels of mexiletine by increasing metabolism. Use Caution/Monitor.
- fexinidazole
fexinidazole will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- fosphenytoin
fosphenytoin decreases levels of mexiletine by increasing metabolism. Use Caution/Monitor.
- green tea
mexiletine increases levels of green tea by decreasing elimination. Use Caution/Monitor. (Caffeine). Combination may increase caffeine levels. Caution should be taken in patients with cardiac arrhythmias. Avoid or limit intake of caffeine.
- haloperidol
haloperidol will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. If concurrent use cannot be avoided, cautious dosing and telemetric monitoring is advised
haloperidol and mexiletine both increase QTc interval. Use Caution/Monitor. - hawthorn
hawthorn increases effects of mexiletine by pharmacodynamic synergism. Use Caution/Monitor.
- imatinib
imatinib will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- imipramine
mexiletine will increase the level or effect of imipramine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- isoniazid
isoniazid will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- lidocaine
mexiletine will increase the level or effect of lidocaine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- maraviroc
maraviroc will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- marijuana
marijuana will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- modafinil
modafinil will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- nilotinib
nilotinib will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- olanzapine
mexiletine will increase the level or effect of olanzapine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC)
ombitasvir/paritaprevir/ritonavir & dasabuvir (DSC) will increase the level or effect of mexiletine by decreasing metabolism. Modify Therapy/Monitor Closely. Caution is warranted and therapeutic concentration monitoring (if available) is recommended for antiarrhythmics when coadministered with Viekira Pak
- parecoxib
parecoxib will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- peginterferon alfa 2a
peginterferon alfa 2a will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- peginterferon alfa 2b
peginterferon alfa 2b, mexiletine. Other (see comment). Use Caution/Monitor. Comment: When patients are administered peginterferon alpha-2b with CYP2D6 substrates, the therapeutic effect of these drugs may be altered. Peginterferon alpha-2b may increase or decrease levels of CYP2D6 substrate.
- pentobarbital
pentobarbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- pentoxifylline
mexiletine will increase the level or effect of pentoxifylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- perphenazine
perphenazine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- phenobarbital
phenobarbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- phenytoin
phenytoin decreases levels of mexiletine by increasing metabolism. Use Caution/Monitor.
- pipemidic acid
pipemidic acid will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- primidone
primidone will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- propafenone
propafenone will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- quinacrine
quinacrine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- ramelteon
mexiletine will increase the level or effect of ramelteon by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- ranolazine
ranolazine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- rasagiline
mexiletine will increase the level or effect of rasagiline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Recommended dose of rasagiline is 0.5mg daily in combination with CYP1A2 inhibitors.
- rifampin
rifampin will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- ritonavir
ritonavir will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor. Monitor patients for signs and symptoms of mexiletine toxicity (nausea, dizziness, cardiac arrhythmias). Therapeutic concentration monitoring is recommended for mexiletine, if available. Reduce doses of mexiletine as required.
- ropinirole
mexiletine will increase the level or effect of ropinirole by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- rucaparib
rucaparib will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP1A2 substrates, if clinically indicated.
- secobarbital
secobarbital will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- sevelamer
sevelamer decreases levels of mexiletine by increasing elimination. Use Caution/Monitor.
- smoking
smoking will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- sodium bicarbonate
sodium bicarbonate will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium citrate/citric acid
sodium citrate/citric acid will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium lactate
sodium lactate will increase the level or effect of mexiletine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- stiripentol
stiripentol, mexiletine. affecting hepatic enzyme CYP1A2 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP1A2 inhibitor and inducer. Monitor CYP1A2 substrates coadministered with stiripentol for increased or decreased effects. CYP1A2 substrates may require dosage adjustment.
- tasimelteon
mexiletine will increase the level or effect of tasimelteon by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor. Avoid coadministration; potentially large increase in tasimelteon exposure and greater risk of adverse reactions with strong CYP1A2 inhibitors
- terbinafine
mexiletine will increase the level or effect of terbinafine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- teriflunomide
teriflunomide decreases levels of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- theophylline
mexiletine will increase the level or effect of theophylline by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- thioridazine
thioridazine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- tipranavir
tipranavir will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- tobacco use
tobacco use will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- venlafaxine
venlafaxine will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Use Caution/Monitor.
- verapamil
verapamil will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
- warfarin
mexiletine will increase the level or effect of warfarin by Other (see comment). Use Caution/Monitor. Warfarin's less potent R-enantiomer is metabolized in part by CYP3A4 (and also CYP1A2 and CYP2C19). Monitor INR more frequently if coadministered with inhibitors of these isoenzymes and adjust warfarin dose if needed.
- zileuton
zileuton will increase the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Use Caution/Monitor.
Minor (9)
- antipyrine
mexiletine will increase the level or effect of antipyrine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- asenapine
mexiletine will increase the level or effect of asenapine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- caffeine
mexiletine will increase the level or effect of caffeine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- frovatriptan
mexiletine will increase the level or effect of frovatriptan by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- lily of the valley
mexiletine, lily of the valley. Either increases toxicity of the other by pharmacodynamic synergism. Minor/Significance Unknown.
- omeprazole
omeprazole will decrease the level or effect of mexiletine by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- ondansetron
mexiletine will increase the level or effect of ondansetron by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- riluzole
mexiletine will increase the level or effect of riluzole by affecting hepatic enzyme CYP1A2 metabolism. Minor/Significance Unknown.
- sertraline
sertraline will increase the level or effect of mexiletine by affecting hepatic enzyme CYP2D6 metabolism. Minor/Significance Unknown.
Adverse Effects
>10%
Nausea (40%)
Vomiting (40%)
Heartburn (40%)
Ataxia (20%)
Dizziness (20-25%)
Lightheadedness (11-25%)
Tremor (13%)
1-10%
Coordination difficulties (10%)
Palpitation (4-7%)
Hypotension (4-8%)
Angina (2%)
Headache (5-7%)
Depression (2%)
Xerostomia (3%)
Proarrhythmia (10-15%)
Rash (4%)
Insomnia (5-7%)
Confusion (5-7%)
Chest pain (3-8%)
Abdominal pain (1%)
Dyspnea (3%)
Constipation or diarrhea (4-5%)
Premature ventricular contractions (1-2%)
Blurred vision (5-7%)
Nystagmus (6%)
Frequency Not Defined
Edema
Exacerbation of CHF
Pulmonary fibrosis
Proarrhythmia
Convulsions
Mouth sores
Tinnitus
Systemic lupus erythematosus
Warnings
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
Contraindications
Hypersensitivity to mexiletine
Cardiogenic shock, preexisting 2°/3° AV block without pacemaker
Cautions
Use caution in CHF, hypotension, history of seizures
Monitor and adjust dose to prevent QTc prolongation
Patients with second or third-degree heart block may be treated if continuously monitored; use caution when used in such patients or in patients with pre-existing sinus node dysfunction or intraventricular conduction abnormalities
Use in less severe arrhythmias not recommended; avoid in treatment of asymptomatic ventricular premature contractions or conduction disturbances
Some abnormal liver function tests reported in first few weeks of therapy; most have been observed in setting of congestive heart failure or ischemia; patients with liver disease should be followed carefully while receiving therapy; caution should also be observed in patients with hepatic dysfunction secondary to congestive heart failure
Rare instances of severe liver injury, including hepatic necrosis, reported in association with treatment; recommended that patients in whom an abnormal liver test has occurred, or who have signs or symptoms suggesting liver dysfunction, be carefully evaluated; if persistent or worsening elevation of hepatic enzymes is detected, consider discontinuing therapy
Prior to use electrolyte imbalances (especially hypokalemia or hypomagnesemia) must be corrected
Avoid concurrent drug therapy or dietary regimens which may markedly alter urinary pH during therapy; the minor fluctuations in urinary pH associated with normal diet do not affect excretion of drug
Marked leukopenia, agranulocytosis and mild depressions of leukocytes and thrombocytopenia reported (rare); If significant hematologic changes observed, patient should be carefully evaluated, and, if warranted, therapy should be discontinued; blood counts usually return to normal within one month of discontinuation
Pregnancy & Lactation
Pregnancy Category: C
Lactation: enters breast milk at concs comparable to maternal plasma (AAP Committee states compatible w/ nursing)
Pregnancy Categories
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.Pharmacology
Mechanism of Action
Class 1B antidysrhythmic; combines with fast Na channels & thereby inhibits recovery after repolarization resulting in decreasing myocardial excitability & conduction velocity
Pharmacokinetics
Bioavailability: 80-90%
Protein Bound: 50-60%
Half-Life: 10-14 hr (adults)
Peak Plasma Time: 2-3 hr (PO)
Therapeutic range: 0.5-2 mcg/mL
Toxicity range: >2 mcg/mL
Vd: 5-7 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 10-15%
Dialyzable: HD: No; PD: No
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| mexiletine oral - | 150 mg capsule |  | |
| mexiletine oral - | 250 mg capsule |  | |
| mexiletine oral - | 200 mg capsule |  | |
| mexiletine oral - | 250 mg capsule |  | |
| mexiletine oral - | 200 mg capsule |  | |
| mexiletine oral - | 150 mg capsule |  | |
| mexiletine oral - | 250 mg capsule |  | |
| mexiletine oral - | 200 mg capsule |  | |
| mexiletine oral - | 150 mg capsule |  | |
| mexiletine oral - | 200 mg capsule |  | |
| mexiletine oral - | 150 mg capsule |  |
Copyright © 2010 First DataBank, Inc.
Patient Handout
mexiletine oral
MEXILETINE - ORAL
(mex-IL-e-teen)
COMMON BRAND NAME(S): Mexitil
WARNING: Though this medication often gives great benefits to people with irregular heartbeat, it may rarely cause a serious new irregular heartbeat. When starting treatment with this drug, your doctor may recommend that you stay in the hospital for proper monitoring. Talk with your doctor about the benefits and risks of taking this medication for your condition.
USES: This medication is used to treat certain types of serious (possibly fatal) irregular heartbeat (such as sustained ventricular tachycardia). It is used to restore normal heart rhythm and maintain a regular, steady heartbeat. Mexiletine is known as an anti-arrhythmic drug. It works by blocking certain electrical signals in the heart that can cause an irregular heartbeat. Treating an irregular heartbeat can decrease the risk for blood clots, and this effect can reduce your risk of heart attack or stroke.
HOW TO USE: Take this medication by mouth with a full glass of water (8 ounces/240 milliliters and food or an antacid, usually 2 to 3 times daily or exactly as directed by your doctor. Taking this medication with food or an antacid helps to decrease certain side effects (nausea, heartburn). Ask your pharmacist if you have questions about which antacids to use with this medication.Dosage is based on your age, liver function, medical condition, and response to treatment.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.Tell your doctor if your condition does not improve or if it worsens.
SIDE EFFECTS: See also Warning section.Nausea, vomiting, heartburn, dizziness, lightheadedness, vision problems (such as blurred vision), headache, shaking, nervousness, or problems with muscle control (coordination difficulties) may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain), signs of liver problems (such as nausea/vomiting that doesn't stop, stomach/abdominal pain, yellowing eyes/skin, dark urine).Get medical help right away if you have any very serious side effects, including: chest pain, seizure.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: fever, swollen lymph nodes, rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking mexiletine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: other heart problems (such as heart failure, slow heartbeat, previous heart attack), liver problems, seizure disorder.This drug may make you dizzy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.This medication passes into breast milk. However, this drug is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug are: caffeine, theophylline, drugs that may affect the acid level of urine (such as sodium bicarbonate, large doses of vitamin C).Other medications can affect the removal of mexiletine from your body, which may affect how mexiletine works. Examples include cimetidine, fluvoxamine, propafenone, anti-seizure drugs (such as phenytoin, phenobarbital), among others.
OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: drowsiness, confusion, fainting, seizures.
NOTES: Do not share this medication with others.Lab and/or medical tests (such as EKG, blood pressure) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
MISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
MEDICAL ALERT: Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).
Information last revised January 2023. Copyright(c) 2023 First Databank, Inc.
IMPORTANT: HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
Formulary
Adding plans allows you to compare formulary status to other drugs in the same class.
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.
