Moricizine hydrochloride
Moricizine hydrochloride (Ethmozine)
Moricizine hydrochloride
(mor- IS-ih-zeen)
Pregnancy Category: B Ethmozine (Rx)

Classification: Antiarrhythmic, class I

See Also: See also Antiarrhythmic Agents .

Action/Kinetics: Causes a stabilizing effect on the myocardial membranes as well as local anesthetic activity. Shortens phase II and III repolarization leading to a decreased duration of the action potential and an effective refractory period. Also, there is a decrease in the maximum rate of phase O depolarization and a prolongation of AV conduction in clients with ventricular tachycardia. Whether the client is at rest or is exercising, has minimal effects on cardiac index, stroke index volume, systemic or pulmonary vascular resistance or ejection fraction, and pulmonary capillary wedge pressure. There is a small increase in resting BP and HR. The time, course, and intensity of antiarrhythmic and electrophysiologic effects are not related to plasma levels of the drug. Onset: 2 hr. Peak plasma levels: 30-120 min. t 1/2: 1.5-3.5 hr (reduced after multiple dosing). Duration: 10-24 hr. 95% is protein bound. Significant first-pass effect. Metabolized almost completely by the liver with metabolites excreted through both the urine and feces; the drug induces its own metabolism. Food delays the rate of absorption resulting in lower peak plasma levels; however, the total amount absorbed is not changed.

Uses: Documented life-threatening ventricular arrhythmias (e.g., sustained VT) where benefits of the drug are determined to outweigh the risks. Investigational: Ventricular premature contractions, couplets, and nonsustained VT.

Contraindications: Preexisting second- or third-degree block, right bundle branch block when associated with bifascicular block (unless the client has a pacemaker), cardiogenic shock. Lactation.

Special Concerns: There is the possibility of increased risk of death when used in clients with non-life-threatening cardiac arrhythmias. Safety and effectiveness in children less than 18 years of age have not been determined. Geriatric clients have a higher rate of side effects. Increased survival rates following use of antiarrhythmic drugs have not been proven in clients with ventricular arrhythmias. Use with caution in clients with sick sinus syndrome due to the possibility of sinus bradycardia, sinus pause, or sinus arrest. Use with caution in clients with CHF.

Side Effects: CV: Proarrhythmias, including new rhythm disturbances or worsening of existing arrhythmias; ECG abnormalities, including conduction defects, sinus pause, junctional rhythm, AV block; palpitations, sustained VT cardiac chest pain, CHF, cardiac death hypotension, hypertension, atrial fibrillation, atrial flutter, syncope, bradycardia, cardiac arrest, MI, pulmonary embolism vasodilation, thrombophlebitis, cerebrovascular events. CNS: Dizziness (common), anxiety, headache, fatigue, nervousness, paresthesias, sleep disorders, tremor, anxiety, hypoesthesias, depression, euphoria, somnolence, agitation, confusion, seizures hallucinations, loss of memory, vertigo, coma. GI: Nausea, dry mouth, abdominal pain, vomiting, diarrhea, dyspepsia, anorexia, ileus, flatulence, dysphagia, bitter taste. Musculoskeletal: Asthenia, abnormal gait, akathisia, ataxia, abnormal coordination, dyskinesia, pain. GU: Urinary retention, dysuria, urinary incontinence, urinary frequency, impotence, kidney pain, decreased libido. Respiratory: Dyspnea, apnea, asthma, hyperventilation, pharyngitis, cough, sinusitis. Ophthalmologic: Nystagmus, diplopia, blurred vision, eye pain, periorbital edema. Dermatologic: Rash, pruritus, dry skin, urticaria. Miscellaneous: Sweating, drug fever, hypothermia, temperature intolerance, swelling of the lips and tongue, speech disorder, tinnitus, jaundice.

Laboratory Test Alterations: Bilirubin and liver transaminases.

Overdose Management: Symptoms: Vomiting, hypotension, lethargy, worsening of CHF, MI, conduction disturbances, arrhythmias (e.g., junctional bradycardia, VT, ventricular fibrillation, asystole), sinus arrest, respiratory failure. Treatment: In acute overdose, induce vomiting, taking care to prevent aspiration. Hospitalize and closely monitor for cardiac, respiratory, and CNS changes. Provide life support, including an intracardiac pacing catheter, if necessary.

Drug Interactions: Cimetidine / Plasma moricizine levels R/T excretion Digoxin / Additive prolongation of the PR interval (but no significant increase in the rate of second- or third-degree AV block) Propranolol / Additive prolongation of the PR interval Theophylline / Plasma theophylline levels R/T rate of clearance

How Supplied: Tablet: 200 mg, 250 mg, 300 mg

Dosage
?Tablets Antiarrhythmic.
Adults: 600-900 mg/day in equally divided doses q 8 hr. If needed, the dose can be increased in increments of 150 mg/day at 3-day intervals until the desired effect is obtained. In clients with hepatic or renal impairment, the initial dose should be 600 mg or less with close monitoring and dosage adjustment.