Advertisements

Морацизин

Quick links to important sections

Морацизин

Advertisements

Medically reviewed

Marina Burgos

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Advertisements

Overview of Морацизин

Quick Facts

Property Description
Active Ingredient Moracizine hydrochloride (Moricizine)
Form Oral Tablet
Pharmacological Class Antiarrhythmic Agent (Vaughan-Williams Class IC)
General Purpose Stabilizing abnormal heart rhythms
Origin Synthetic, Phenothiazine Derivative

What is Moracizine and What is its Composition?

Moracizine (Морацизин), officially identified by its International Nonproprietary Name (INN) Moracizine hydrochloride, is a synthetic, prescription pharmaceutical primarily engineered to modulate the electrical activity within the heart. The medicine is structurally defined as a phenothiazine derivative, a chemical lineage that distinguishes it from many other cardiac drugs. It is a single-ingredient product, manufactured and administered as an oral tablet, combining the active compound with standard pharmaceutical excipients to establish the final dosage form. This medication is typically recognized for its use in adult patient groups.

What Type of Drug is Moracizine? (Pharmacological Classification)

Moracizine is classified as an antiarrhythmic agent, the general drug class dedicated to treating and preventing disturbances in the heart's rhythm. Specifically, Moracizine falls into the Class IC category of the Vaughan-Williams classification system. This classification identifies the drug's physiological role as a cardiac sodium channel blocker. As a Class IC agent, Moracizine is characterized by its impact on slowing conduction, a mechanism used for managing irregular heartbeats.

What is the General Purpose of Moracizine?

The overarching purpose of Moracizine is to achieve cardiac membrane stability to support a consistent, regulated heartbeat. By inhibiting the fast inward sodium current across heart cell membranes, Moracizine reduces abnormal excitability and slows the speed of electrical conduction. This mechanism helps to counteract the disorganized electrical firing that results in rhythm disturbances, such as ventricular arrhythmias, thereby suppressing erratic contractions and assisting the heart in maintaining a controlled electrical pattern.

Regulatory References

  1. Moricizine Hydrochloride Drug Information - MedlinePlus
Advertisements

What side effects are possible with Морацизин?

Official Safety Profile and Adverse Reactions

The safety profile for Moracizine (Moracizine hydrochloride) is classified according to incidence rates reported in regulatory clinical studies, focusing on both common and serious adverse reactions.


Frequency-Classified Adverse Reactions

The most frequent side effects, often classified as Common (occurring in 2% to 10% or more of patients), primarily involve the Nervous System and Gastrointestinal System. These include Dizziness, Nausea, Headache, Vomiting, Hypoesthesias (numbness/tingling), Sleep disorders, and Fatigue. Numerous other reactions are classified as Less Common.


System-Organ Classes and Serious Risks

Adverse reactions are formally grouped by System-Organ Class. Cardiac Disorders present the most clinically significant risk, specifically the potential for New or Worsening Arrhythmias (Proarrhythmia). Other serious events documented in regulatory sources include rare reports of Seizure and Severe Hypersensitivity Reactions.


Safety Patterns and Constraints

Official safety summaries note that noncardiac adverse effects often appear frequently in the first one or two weeks of therapy and that the incidence of neurological and gastrointestinal complaints may increase with long-term exposure (over 3 months). Close monitoring, specifically Electrocardiogram (ECG) monitoring, is required throughout therapy to assess the drug's effect on cardiac conduction. For patients with Hepatic or Renal Impairment, official labels dictate that lower initial doses and close monitoring are required due to altered drug clearance, and the drug's safety is not established for pediatric patients.

Advertisements

Overdose and Emergency Response

Overdose and When to Seek Help

Overdosage with Moracizine is documented in regulatory sources as a serious event with potentially life-threatening clinical manifestations. The primary concern relates to the Cardiovascular System, with severe outcomes including ventricular fibrillation, asystole, and sinus arrest, alongside hypotension and various conduction disturbances. Fatal outcomes have been reported following high-dose exposures, confirming the extreme severity of overdosage.

Manifestations involving other physiological systems include signs such as emesis, lethargy, syncope, coma, and respiratory depression. Because of the documented severity and risk of cardiovascular collapse, regulatory information mandates that patients experiencing an overdosage must be immediately transferred for hospitalization. During this time, continuous monitoring for cardiac, respiratory, and CNS changes is required.

Acute management procedures described in official documents include performing appropriate gastric evacuation and providing advanced life support systems where necessary, which may involve an intracardiac pacing catheter. It is officially stated that no specific antidote for Moracizine is known, meaning treatment relies entirely on supportive clinical measures. Additionally, patients with existing hepatic or renal impairment may require close monitoring, including ECG interval measurement, due to heightened sensitivity.

Advertisements

Therapeutic Uses of Морацизин

What Морацизин Treats: Main Uses and Benefits

Addressing Symptoms of Disruptive Heart Rhythm Disorders

Moracizine is relevant for easing symptoms associated with irregular heartbeats, a condition involving symptoms related to heightened physiological activity in the heart. It is applied across domains where additional symptomatic support is needed for rhythm disturbances. It is used in situations involving certain distressing symptoms, primarily for conditions characterized by episodic or fluctuating manifestations of rhythm issues.

Providing Support During Symptomatic Episodes

This medication may be part of symptomatic management during phases when symptoms become more noticeable and create noticeable physiological strain. It assists in addressing symptom clusters that may become intense or disruptive, such as palpitations or flutters that interfere with daily functioning. This is relevant when short-term symptomatic assistance is needed to help the patient cope more steadily. It may assist with supportive relief when symptoms interfere with routine activities.


Promoting Day-to-Day Functional Stability

The drug contributes to easing the overall symptom load for patients with recurrent rhythm issues. It helps maintain a sense of stability when the condition produces significant symptomatic burden, providing supportive relief. It is considered relevant in contexts involving heightened systemic burden and supports improved day-to-day comfort during symptomatic periods.

Quick Fact: Support for Palpitations and Flutters

Advertisements

Eligibility and Restrictions for Use

Who can and cannot use Морацизин?

The eligibility profile for Moracizine is strictly defined by regulatory documents, emphasizing specific cardiac and organ function criteria. The information below details documented exclusions and restrictions.

Eligibility Scope

Use is contraindicated and absolutely prohibited for patients with pre-existing second- or third-degree AV block, bifascicular block (right bundle branch block associated with left hemiblock) unless a ventricular pacemaker is present, cardiogenic shock, or known hypersensitivity to the drug.

The medicine is reserved for use only in the adult population diagnosed with serious and life-threatening ventricular arrhythmias.

Eligibility is restricted and requires caution for individuals with significant hepatic (liver) or renal (kidney) dysfunction, and pre-existing congestive heart failure. Therapy initiation in these patients requires careful monitoring due to potential for excessive pharmacological effects.

Special Population Status

Safety and effectiveness have not been established in the pediatric patient population. For pregnant individuals, the drug is assigned to Pregnancy Category B by the U.S. FDA. Moracizine is excreted into human milk, requiring a decision regarding the continuation of nursing.

Advertisements

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information describes specific pharmacokinetic and pharmacodynamic interactions for Moracizine. The profile includes formal prohibitions for patients with certain pre-existing cardiac conduction abnormalities.

Interactions Affecting Drug Exposure

Co-administration with Cimetidine reduces the elimination rate of Moracizine, which increases Moracizine plasma concentrations. Conversely, Moracizine has been shown to induce the metabolism of Theophylline, potentially decreasing Theophylline’s plasma exposure. Moracizine also acts as an inducer of its own metabolism, a factor in its pharmacokinetic profile.

Pharmacodynamic Interactions

Co-administration with Digoxin has been documented to cause an additive electrophysiologic effect, which may result in an excessive prolongation of the PR interval. Similar effects on ECG intervals (PR, QRS) may occur when Moracizine is used with other medications that affect cardiac conduction, such as beta-blockers or calcium channel blockers.

Substance and Population Notes

  • Alcohol may impair the ability to perform potentially hazardous tasks due to possible additive central nervous system effects.
  • Patients with severe hepatic impairment exhibit reduced plasma clearance and an increased half-life of Moracizine, increasing the risk of exaggerated pharmacological effects.
  • Co-administration with Warfarin has been noted to potentially increase the risk of bleeding, suggesting an effect on the anticoagulant pathway.
Advertisements

Mechanism of Action

Blocking the Fast Sodium Channel

Moracizine's action involves altering the electrical activity of the heart through interaction with ion channels that govern impulse generation and conduction. Its focus is on reducing the excitability of cardiac tissue through a rate-dependent mechanism. The molecule acts as a selective inhibitor of the voltage-gated sodium channel ( Nav1.5) in heart cells. By blocking the rapid flow of sodium ions ( Na^+) into the cell, Moracizine reduces the speed and strength of the initial electrical spark, resulting in reduced electrical conduction velocity across the tissue.

Use-Dependent Electrical Modulation

Moracizine exhibits a characteristic use-dependent mechanism: the degree of sodium channel block intensifies when the electrical firing rate of the heart is high. This leads to a deeper block under conditions of high-frequency electrical activity. This physiological consequence is a reduction in spontaneous electrical activity due to the dampening of rapid electrical impulses and altered propagation through electrical pathways.

Action Potential Dynamics

A secondary focus is the inhibition of the late sodium current ( I NaL), a small persistent current that influences the latter stages of the heart cell's electrical cycle. This dual action modifies the duration of the action potential and recovery phase, contributing to altered electrical signaling dynamics and reduced potential for spontaneous electrical activity in the tissue.

Advertisements

Dosage and Administration Information

Official Administration Guidelines for Moracizine

Moracizine is strictly for oral administration as a tablet, available in strengths of 200 mg, 250 mg, and 300 mg. The drug is typically administered every eight hours, resulting in a total daily dose divided into three equally spaced intervals.

Standard Dosing and Schedule

The usual adult dosage range is 600 mg to 900 mg per day. Treatment is typically initiated with a starting dose of 200 mg every eight hours. If needed, the total daily dose may be gradually titrated upward in increments of 150 mg at intervals of at least three days until the appropriate response is reached. The maximum recommended daily intake is 900 mg.

While the drug is commonly administered three times daily, the same total daily dose may sometimes be given in a twice-daily (Q12H) schedule for convenience in patients whose rhythm is well-controlled on the thrice-daily regimen. The tablet may be taken with or without food; however, consumption within 30 minutes after a meal is noted to slow the rate of absorption.

Contextual Constraints and Adjustments

Therapy initiation and subsequent dosage adjustments generally require hospitalization with continuous electrocardiographic (ECG) monitoring. Furthermore, specific dose reductions are required for certain adult populations: patients with significant renal (kidney) or hepatic (liver) impairment should be started at 600 mg per day or less and closely monitored before any dosage adjustment is made.

Advertisements

Recent Clinical Evidence

Research evidence / Overview of studies for Морацизин

Evidence for Use in Symptom-Related Ventricular Arrhythmias

The initial clinical evaluation of Moracizine was studied for conditions characterized by fluctuating or episodic manifestations of frequent, chronic irregular heartbeats, known as ventricular arrhythmias. Research in this area primarily examined the drug's activity using short-term randomized controlled trials (RCTs). These studies were conducted during periods of increased symptom activity and relevant in trials assessing short-term or episodic symptom patterns of the heart.

The main research objective in these trials research examined outcomes related to systemic or functional imbalance by measuring the frequency and complexity of abnormal electrical events (ventricular premature beats, or VPBs). Findings from these studies describe patterns observed in the studies where differences in the measured frequency of these extra heartbeats were noted across groups.

Research on Antiarrhythmic Strategy After a Heart Attack (The CAST II Trial)

A major focus of the research landscape involves a large-scale, rigorous randomized, double-blind, placebo-controlled trial, known as CAST II. This study was evaluated in a specific, high-risk population: adult patients who had recently survived a myocardial infarction (heart attack) and still had frequent, mild ventricular ectopy. The primary outcomes research examined were hard clinical endpoints, including all-cause mortality and cardiac arrest.

Findings from this trial data show patterns related to an unexpected risk: the trial was discontinued prematurely in the Moracizine group because the research indicated that this strategy—arrhythmia suppression with this drug class after a heart attack—did not correlate with changes in all-cause mortality compared to placebo in this specific patient group. The study results reflect the specific conditions under which they were conducted.

What is Still Uncertain About the Research for Морацизин

Long-term effects are not fully established, as follow-up durations were limited in many studies. The relationship between the observed suppression of VPBs and patient-reported outcomes describing perceived discomfort or overall functional stability is not consistently documented across all available data. There is also a key finding regarding the definitive trial (CAST II), where research indicated that the strategy of arrhythmia suppression in post-MI patients was associated with an increase in mortality, which evidence highlights what is known—and what is still uncertain about the overall risk/benefit balance of this drug class in specific cardiac contexts.

Key Studies & References Moricizine: pharmacodynamic, pharmacokinetic, and therapeutic profile of a new antiarrhythmic

Advertisements

Frequently Asked Questions (FAQ)

Common questions about Морацизин (FAQ)

Q: What is Морацизин and how does it work?

Морацизин is an antiarrhythmic medicine that helps treat abnormal heart rhythms (arrhythmias). It belongs to the class Ic group of antiarrhythmic drugs. Морацизин works by blocking sodium channels in the heart muscle cells. This action slows down the electrical conduction in the heart, helping to restore a normal and steady heart rhythm.


Q: What types of arrhythmias is Морацизин used to treat?

Морацизин is typically used to manage life-threatening or severely symptomatic ventricular arrhythmias, such as ventricular tachycardia and ventricular premature beats. It is also used to treat certain types of supraventricular arrhythmias, including paroxysmal atrial fibrillation/flutter and paroxysmal supraventricular tachycardia (PSVT), when other treatments have failed or are not tolerated.


Q: How long does Морацизин take to start working?

After taking an oral dose, Морацизин is rapidly and almost completely absorbed from the gastrointestinal tract. The maximum concentration in the blood is usually reached within 1 to 2 hours. However, the full therapeutic effect, or the point at which your heart rhythm is consistently controlled, is determined by your physician based on your condition and response to the medicine.


Q: Can I take Морацизин if I have a history of heart failure or a recent heart attack?

No, Морацизин is contraindicated (should not be used) in people with certain pre-existing heart conditions. This includes people with congestive heart failure (CHF) and those who have had a recent heart attack (myocardial infarction), particularly within the previous three months, as it can worsen these conditions and increase the risk of serious complications. Your doctor will assess your full medical history before prescribing Морацизин.


Q: What are the common side effects of Морацизин?

Some of the common side effects of Морацизин include dizziness, headache, nausea, and stomach upset. It can also cause a significant side effect called proarrhythmia, which means the medicine intended to treat an arrhythmia can sometimes cause a new or worsened abnormal heart rhythm. It is important to report any new or worsening symptoms to your doctor immediately. Other less frequent but important side effects can include fatigue and blurred vision.


Q: Can Морацизин interact with other medicines I am taking?

Yes, Морацизин can interact with many other medicines. It is important to inform your doctor and pharmacist about all prescription and non-prescription medicines, vitamins, and herbal supplements you are currently taking. Notable interactions include those with other antiarrhythmic drugs, which can increase the risk of severe side effects, and certain medicines that affect the liver enzymes responsible for breaking down Морацизин, such as cimetidine. Adjustments to your dose or close monitoring may be necessary.

Advertisements

How should Морацизин be stored and disposed of?

Storage and Disposal Requirements

Moracizine hydrochloride (Ethmozine) must be stored according to regulatory labeling to maintain its stability. The product requires storage at Controlled Room Temperature, which is officially defined as a range between 20 C and 25 C (68 F to 77 F), with permitted excursions up to 30 C.

Storage Condition Requirement
Temperature 20 C to 25 C; do not freeze.
Protection Protect from light and moisture.
Packaging Store in the original container, kept tightly closed.

For safety, the medication must be secured out of the sight and reach of children. Disposal of any unused or expired Moracizine must follow local pharmaceutical waste regulations. Do not flush the tablets down the toilet or throw them in the household trash unless specifically instructed by official guidelines, as drug take-back programs are the preferred method.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

Available in countries:

Equivalent of Морацизин found in:

A-Z Index: