Mexiletine
Mexiletine belongs to class IB-antiarrhythmic group of medicines. Mexiletine is a sodium channel blocking agent. Chemically Mexiletine is 1-methyl-2-(2, 6-xylyloxy) ethylamine. Mexiletine is used as an antiarrhythmic agent and resembles lidocaine in its electro-physiological effects in the heart and has the same uses and equal efficacy but is superior in that it may be used in chronic treatment. its primary advantage is oral efficacy and relatively long half-life. its useful actions are primarily limited to ventricular dysrhythmias. It is used to treat arrhythmia within heart or serious irregular heart beat.
Primary Characteristics
Mexiletine is also known as Mexiletine (HCl).
It is of Synthetic origin and belongs to Phenoxyaminoketone.
It belongs to Na-Channel Antiarrhythmic antagonist pharmacological group on the basis of mechanism of action and also classified in Anti arrhythmic agents pharmacological group.
Molecular Weight: 215.7 · pKa: 8.4 · Solubility in Water: 1 in 2 · Solubility in Alcohol: 1 in 3 · Non-proprietary name: Mexiletine (HCl).
Pharmacokinetics
Absorption: Mexiletine has an oral bioavailability is 96.5% (±1.5%), pre-systemic (first-pass) metabolism accounts for 85%.
Distribution: Mexiletine has a volume of distribution is 7.25 l/kg. plasma protein binding is 65 %.
Elimination: it is metabolised via Hepatic, plasma half-life is 12.6 hr, renal excretion is 90 %.
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Indications
Mexiletine is primarily indicated in conditions like Cardiac arrhythmia, Myocardial infarction, Postinfarct arrythmias, Ventricular arrhythmias, Ventricular arrhythmias, especially after myocardial infarction, Wolf-parkinson-white syndrome.
Mexiletine is also indicated for secondary conditions like Pain.
Contraindications
Mexiletine is contraindicated in conditions like Cardiogenic shock.
Dosage
Mexiletine's dosage details are as follows:
| Dose | Single Dose | Frequency | Route | Instructions |
|---|---|---|---|---|
| Adult Dosage | ||||
| 175 mg | 175 mg | — | IV | At atrate of 25mg/min followed by an infusion atarate of 250mg over 1 hr , 250 over next 2 hours & 500 ug/min for maintanence . |
| 200 – 250 mg | — | — | PO | Frequency could be 3-4 times a day, 2 hours after loading dose, |
| 750 mg | 750 mg | — | PO | In divided dose up to 1.2g maitenence dose . |
| Paediatric Dosage (20kg) | ||||
| 3.25 mg/kg | 3.25 mg/kg | Every 8h | Oral | |
| Neonatal Dosage (3kg) | ||||
| 3.25 mg/kg | 3.25 mg/kg | Every 8h | Oral | |
Drug Interactions
Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Side Effects
Mexiletine in overdosage may give rise to further complications which include Convulsions , Ataxia , Fever , Allergic reactions , Jaundice , Jaundice , Leucopenia, Agranulocytosis , Depression , Wheezing , Chest pain , Cough , Psychiatric disorders.
Mexiletine produces potentially life-threatening effects which include Bradycardia , Hypotension, Hepatitis . Careful monitoring is needed with proper medical management.
The signs and symptoms that are produced after acute overdosage of Mexiletine are Convulsions , Seizures, fatigue, Pulmonary fibrosis, Unconsciousness, Thrombocytopenia , Heart block, Ventricular asystole, Numbness , Irregularities in heart rhythm.
Mexiletine is known to cause more or less tolerable side effects which are usually transient. These include Constipation , Disorientation, Dizziness, Headache, Heart burn, Nausea, Oesophageal ulcerations, Rashes , Termors, Trembling, Vomiting .
Warnings / Precautions
Interference in Pathology
Mexiletine may interfere in the diagnosis of Abnormal LFTs .
Available Brands
None recorded.
Storage Conditions
Drug Classification
- 1.12.2 — Antiarrhythmic drugs