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Calaptin

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Calaptin

Calaptin_FI

Method of action: Antianginal, Antiarrhythmic, Antihypertensive, Cardiovascular Agent, Hypotensive

Treatment option: Arrhythmia, Hyperlipidemia, Hypertension, Diabetic Kidney Disease, Cerebrovascular Accident, Smoking, Paroxysmal Supraventricular Tachycardia, Smoking Cessation, Diabetes Mellitus, Heart Failure

Medically reviewed

Marina Burgos

Last updated on 10/01/2026

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.

Overview of Calaptin

Quick Facts

Property Description
Active Ingredient Verapamil Hydrochloride
Pharmacological Class Non-dihydropyridine Calcium Channel Blocker
Form Tablet (Immediate- and Sustained-Release), Solution for Injection
Common Use Stabilizing heart rhythm and managing blood flow
Origin Synthetic (Phenylalkylamine derivative)

What is Calaptin and What Class Does It Belong To?

Calaptin is a synthetic, prescription-only medication whose single active component is Verapamil Hydrochloride, developed for stabilizing the cardiovascular system. It is officially classified as a Calcium Ion Antagonist or Calcium Channel Blocker, belonging specifically to the non-dihydropyridine subgroup of this class. Verapamil's mechanism, which involves impeding the influx of calcium ions into specific cardiac and vascular cells, is characterized by its effect on both heart rate and blood vessel tone simultaneously. This dual action is a differentiating feature compared to other CCBs that are primarily vasodilators. The substance’s status as a phenylalkylamine derivative highlights its foundational role in the development of antiarrhythmic and antihypertensive therapies.

Forms, Variations, and General Therapeutic Aim

Verapamil Hydrochloride is supplied for use via oral administration as tablets (including both immediate-release and sustained-release types) and as a sterile solution for intravenous injection. The primary therapeutic aim of this medicine is to reduce the heart’s overall workload and regulate its electrical rhythm, a need often observed in patients managing persistent cardiac instability. A key variation is the availability of the sustained-release (SR) tablet, which offers the benefit of maintaining therapeutic plasma concentrations with less frequent dosing for long-term patient adherence. Calaptin's action involves reducing systemic vascular resistance and decreasing myocardial oxygen demand.

What side effects are possible with Calaptin?

Possible side effects and safety information

The safety profile of Calaptin (Verapamil Hydrochloride) is categorized by regulatory agencies based on the potential impact on different body systems and the frequency of occurrence documented in clinical studies. The profile is primarily focused on the drug's activity on the cardiovascular system.

Common and System-Organ Adverse Reactions

Adverse reactions are officially grouped by System-Organ Class (SOC), including Gastrointestinal disorders (most notably constipation and dyspepsia), Nervous System disorders (such as dizziness and headache), and General disorders (including fatigue and peripheral edema). Cardiovascular effects like bradycardia (slowed heart rate) and hypotension (decreased blood pressure) are also documented, often classified as uncommon based on official data.

Serious Adverse Reactions and Restrictions

Official labeling defines several serious adverse reactions. These relate mainly to cardiac conduction and function, including High-degree Atrioventricular (AV) Block and the potential for Severe Left Ventricular Dysfunction or Sinus Arrest (except in the presence of a functioning artificial pacemaker). Specific safety restrictions, or contraindications, are documented for individuals with conditions such as Cardiogenic Shock and severe Hypotension. Caution is also advised regarding the use of intravenous verapamil with other heart-affecting medications.

Population and Time-Related Safety Considerations

Regulatory documents note that the drug's elimination half-life may be prolonged in older adults and in patients with hepatic insufficiency (liver impairment). A pattern has been observed where PR interval prolongation may be more apparent during the initial dose titration phase, potentially lessening with chronic use. These statements guide the understanding of the drug's safety characteristics across different patient groups and stages of exposure.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose involving Verapamil Hydrochloride (Calaptin) must be treated as a serious medical emergency. According to official government regulatory documents, exceeding the prescribed dose can lead to life-threatening cardiovascular manifestations.

Immediate medical help or contact with a Poison Control Center is required right away for any suspected overdose.

Documented Overdose Manifestations

Official labeling documents symptoms including:

  • Severe and pronounced Hypotension (low blood pressure).
  • Extreme slowing of the heart rate (Bradycardia), which may progress to Sinus Arrest or Asystole (cardiac arrest).
  • High-degree AV Block (second- or third-degree conduction defects).
  • Other serious effects such as Convulsions, Decreased Mental Status, and Metabolic Acidosis.

Required Emergency Actions

The treatment is defined as supportive, as no specific antidote is listed in the official prescribing information. Management includes procedures like Gastric Lavage and administration of Activated Charcoal, particularly for sustained-release formulations. Supportive measures may include Intravenous Calcium or the use of Vasoactive Drugs to address hypotension.

Due to the risk of delayed symptoms, especially with extended-release tablets, continuous hospital observation is required for at least 48 hours following an overdose event.

Therapeutic Uses of Calaptin

The therapeutic role of Calaptin (Verapamil) is focused on providing supportive management for specific cardiovascular and neurological conditions.

The medication is commonly used for easing symptoms related to supraventricular tachyarrhythmias (fast heart rhythms), for managing the long-term course of Angina Pectoris (chest pain), and for the chronic management of Essential Hypertension (high blood pressure). It is also used for the prophylactic management of cluster headaches.

Quick Fact: Relief for Cardiac Discomfort

Calaptin contributes to easing the overall symptom load by addressing symptoms related to physical discomfort and symptoms related to systemic imbalance. When managing the symptoms of cardiac issues, it helps maintain a sense of stability when symptoms are more noticeable, providing support that assists with managing discomfort.

In these conditions, Calaptin may be applied to support stabilization of the rhythm, may assist with managing the frequency of chest pain episodes, and supports the management of high arterial pressure, assisting with maintaining functional stability and general well-being.

Regulatory References

  1. NIH MedlinePlus overview

Eligibility and Restrictions for Use

Who can and cannot use Calaptin? — Official Regulatory Information

Calaptin, which contains verapamil hydrochloride, is a medicine used primarily to manage high blood pressure and certain heart rhythm problems in eligible adult patients. Regulatory agencies strictly define the populations that must not use this medicine (contraindications) and those who require special consideration.

Classification Population or Condition
Contraindicated Severe left ventricular dysfunction (e.g., severe heart failure)
Contraindicated Hypotension (systolic pressure less than 90 mmHg) or cardiogenic shock
Contraindicated Sick sinus syndrome or second-/third-degree AV block (unless a functioning pacemaker is present)
Contraindicated Atrial flutter/fibrillation with an accessory bypass tract (e.g., Wolff-Parkinson-White syndrome)
Contraindicated Known hypersensitivity to verapamil hydrochloride
Not Recommended Pediatric patients (safety and efficacy are not established)
Special Consideration Hepatic impairment (dose reduction and careful monitoring are advised)
Special Consideration Pregnancy (safety is not established; should only be used if the benefit outweighs the potential risk)
Special Consideration Elderly patients (monitoring is recommended, as the drug's half-life may be prolonged)

This eligibility map is based on official government documents and focuses exclusively on regulatory requirements regarding patient selection, not on therapeutic uses or safety risks outside of explicit prohibitions.

What should I know about interactions with other medicines?

Interactions with other medicines and products

Official regulatory information for verapamil (Calaptin) focuses on two major types of interactions: effects on the cardiovascular system and pharmacokinetic alterations involving liver enzymes and transport proteins.

Interacting Product Category Official Interaction Constraint
Cardiovascular Depressants (e.g., Beta-blockers, Digitalis, Disopyramide, Quinidine) Coadministration can lead to an additive depressant effect on myocardial contractility and/or AV conduction. Intravenous beta-blockers are generally contraindicated in close proximity to intravenous verapamil. Close monitoring is mandated for oral combinations.
CYP3A4 / P-gp Substrates (e.g., Colchicine, Simvastatin, Atorvastatin, Cyclosporine, Everolimus) Verapamil is a moderate inhibitor of the CYP3A4 enzyme and the P-glycoprotein (P-gp) transporter. This inhibition increases the concentration of co-administered drugs that rely on these systems for metabolism or efflux. Specific dose limitations apply to drugs like Simvastatin (e.g., daily dose limit of 20 mg).
CYP3A4 Inducers (e.g., Rifampin, Phenobarbital, St. John's wort) These products can increase the metabolism of verapamil, leading to a reduction in its plasma concentration and potential loss of therapeutic effect. Coadministration is generally avoided or requires careful monitoring.
Alcohol / Grapefruit Juice Concomitant consumption of alcohol is associated with an increase in blood ethanol concentration. Grapefruit juice should be avoided as it can increase verapamil levels.

Co-use with colchicine is not recommended or is contraindicated in patients with renal or hepatic impairment due to significant increases in colchicine exposure.

Mechanism of Action

Calaptin is the L-isomer of verapamil, functioning as a non-dihydropyridine calcium channel blocker (CCB). The molecule acts to inhibit the influx of extracellular calcium ions across the cell membranes of vascular smooth muscle and cardiac myocardium by binding to the L-type voltage-gated calcium channels. Calaptin exhibits a greater affinity for calcium channels in nodal tissue, specifically the sinoatrial and atrioventricular nodes. This interaction modulates cellular calcium flux, inhibiting the excitation-contraction coupling process in the myocardium and smooth muscle cells. The result of this selective antagonism is a decrease in peripheral vascular resistance. Furthermore, by decreasing the heart rate and contractility, Calaptin reduces myocardial oxygen demand. This dual mechanism of action regulates cardiovascular function by targeting both the vasculature and the cardiac conduction system.

Dosage and Administration Information

Administration and Dosage Instructions

Calaptin (verapamil) is administered orally in immediate-release (IR) tablets, extended-release (ER) tablets, or ER capsules. The specific dose is individualized by a healthcare professional and is often started low, then gradually increased (titrated) over days or weeks based on the patient’s response.

Formulation Type Administration Requirements
Immediate-Release (IR) Tablet Typically taken three to four times daily.
Extended-Release (ER) Tablet Swallowed whole; do not crush or chew. May be taken once or twice daily and often with food.
Extended-Release (ER) Capsule Swallowed whole.

Preparation and Timing

To maintain consistent drug levels, the medicine is typically taken at around the same time(s) every day. If an ER capsule cannot be swallowed, the contents (pellets) may be carefully sprinkled onto a tablespoon of applesauce (not hot) and swallowed immediately without chewing, followed by a glass of cool water.

Missed Dose Protocol: If a dose is missed, it is taken as soon as it is remembered, unless it is almost time for the next scheduled dose. In this case, the missed dose is skipped and the regular schedule is continued. A double dose is not taken to make up for a forgotten one.

Special Condition: The official labeling indicates that patients avoid consuming grapefruit or grapefruit juice while taking this medication, as this can affect the amount of verapamil in the body.

Recent Clinical Evidence

Calaptin (Verapamil): Recent Clinical Evidence

Clinical research continues to evaluate the established role of Verapamil (marketed as Calaptin) in managing cardiovascular conditions. As a non-dihydropyridine calcium channel blocker, its primary use is supported by decades of evidence for lowering blood pressure, managing chronic stable angina, and controlling certain types of supraventricular tachyarrhythmias.

Evidence in Hypertension Management

Studies confirm Verapamil's effectiveness in achieving and maintaining target blood pressure goals, both as a monotherapy and in combination with other classes of antihypertensive agents. Research suggests that the extended-release formulation may be particularly beneficial for providing consistent control over a 24-hour period. Recent analyses have focused on its metabolic neutrality, observing that its use does not appear to negatively affect glucose control or lipid profiles, which can be an important consideration for individuals with co-occurring diabetes or dyslipidemia.

Evidence in Angina and Arrhythmia

For chronic stable angina, clinical findings support the drug's action in decreasing myocardial oxygen demand by reducing heart rate and contractility, thereby improving exercise tolerance. In the management of supraventricular tachyarrhythmias, specifically atrial fibrillation and flutter, evidence supports its use for rate control. Studies have shown that Verapamil can decrease the ventricular rate, thereby aiding in the management of symptoms associated with rapid heart rhythms.

Novel Research Areas

Limited, non-pivotal studies have explored potential applications beyond cardiology, including the management of certain headache disorders and the treatment of specific types of tremor. These applications are generally considered off-label and require further large-scale, controlled clinical trials to establish their efficacy and safety profiles.

How should Calaptin be stored and disposed of?

How to Store and Dispose of Calaptin

Official regulatory documents define specific conditions for storing and disposing of Calaptin (Verapamil Hydrochloride) to maintain its stability.

Required Storage and Protection

Item Regulatory Requirement
Temperature Store at Controlled Room Temperature (20 C to 25 C), with excursions up to 30 C permitted.
Environmental Must be Protected from light, moisture, and excess heat, and must not be frozen.
Container Keep in the original container, tightly closed. The injection must remain in its package until use.
Child Safety Must be stored out of the sight and reach of children.

Disposal Requirements

Any unused portion of the injection solution must be discarded immediately after a portion is withdrawn. For expired or unused oral forms, patients are directed to ask a healthcare professional how to dispose of the medicine according to local regulations. The unused product should never be kept.

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

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