Mexiletine Pharmacology

Mexiletine

About Mexiletine

Local anesthetic (lidocaine analogue), sodium channel antagonist, Oral anti-arrhythmic(Class IB).

Mechanism of Action of Mexiletine

Mexiletine is a class 1B anti arrhythmic drug and a local anaesthetic. It exerts it`s action by interacting with a receptor situated within the voltage sensitive Na+ channels and raise the threshold of channel opening. It blocks nerve conductions by decreasing the entry of sodium ions during upstroke of action potential. The rate of rise of action potential and maximum depolarization decreases in a concentration dependent manner and causing slowing of conduction and finally local depolarization fails to reach the threshold potential and conduction block ensures. Na+ permeability fails to increase in response to an impulse or stimulus. Thus the drug exerts it`s local anaesthetic action by membrane stabilizing effect.
It reduces automaticity in Purkinje Fibres by decreasing phase 4 depolarization and increasing threshold voltage. By reducing the rate of 0 phase in depolarization in ischaemic Purkinje fibres it may convert one way block to two way block. It also shortens the effective refractory period and action potential duration of His Purkinje system and suppresses spontaneous ventricular depolarization during diastole

Pharmacokinets of Mexiletine

Absorption: Well absorbed orally. Distribution: Widely distributed in through out the body. Metabolism: About 90% of the drug is metabolized in liver. Excretion: Excreted in urine.

Onset of Action for Mexiletine

30 minutes to two hours

Duration of Action for Mexiletine

N/A

Half Life of Mexiletine

10 to 12 hours

Side Effects of Mexiletine

1.Dizziness
2.Confusion
3.Tremor
4.Ataxia
5.Blurred vision
6.Nausea
7.Vomiting
8.Hypotension
9.Accentuate AV block
10.Bradycardia
11.Worsened arrhythmia
12.Palpitation
13.Chest pain
14.Altered liver function tests

Contra-indications of Mexiletine

1.Hypersensitivity to the drug
2.Second or third degree AV block
3.Cardiogenic shock
4.Sinus node dysfunction
5.Conduction disturbances
6.Recent myocardial infarction

Special Precautions while taking Mexiletine

1.Hepatic impairment
2.Renal impairment
3.Sinus node dysfunction
4.Heart failure
5.Hypotension
6.First degree heart block
7.Seizure disorders
8.Conduction defects

Pregnancy Related Information

Use with caution

Old Age Related Information

Use with caution

Breast Feeding Related Information

Contraindicated

Children Related Information

N/A

Indications for Mexiletine

1.Ventricular arrhythmias
2.Ventricular tachyarrhythmia

Interactions for Mexiletine

Aluminium / Magnesium hydroxide: Absorption of mexiletine slowed.
Hydantoins, Rifampicin: Decreased plasma levels of mexiletine.
Metoclopramide: Mexiletine absorption accelerated.
Urinary acidifiers: In acidic urine, mexiletine clearance increased resulting in decreased serum levels.
Urinary alkalizers: Increased serum levels of mexiletine.

Typical Dosage for Mexiletine

Starts with a loading dose of 400mg. Followed by 200mg 3 - 4 times daily. Increase or decrease the dose in increments of 50 to 100mg every 2 to 3 days until satisfactory control is obtained.
Maximum daily dose: 1200mg.

Schedule of Mexiletine

Storage Requirements for Mexiletine

Store at room temperature and protects from light and moisture.

Effects of Missed Dosage of Mexiletine

Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.

Effects of Overdose of Mexiletine

Discontinue the drug and give supportive and symptomatic treatment. Remove drug from the body by emesis and gastric lavage. Acidification of urine accelerates drug elimination. Atropine may be given to treat Bradycardia and hypotension.

Home Delivery for Mexiletine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including mexiletine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for mexiletine and other medicines and health products. Home delivery services for mexiletine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take mexiletine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for mexiletine before they complete the sale. You can get this information while placing the order for mexiletine with the pharmacy.

Mexiletine is a generic medicine name and there are several brands available for it. Some of the brands for mexiletine might be better known than mexiletine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have mexiletine in stock, you can ask for one of the branded alternatives for mexiletine.