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Isoptin is a calcium channel blocker. The preparation acts directly on the heart, inhibiting the heart’s conduction system, thus extending the time of conduction between the atrium and the ventricle. Isoptin also affects the functioning of blood vessels, reduces the tension in the smooth muscles of the artery walls and the expansion of the arteries. It lowers blood pressure by reducing vascular resistance.
The active substance of the drug isoptin to verapamil. This preparation belongs to the group of drugs – calcium antagonists (also known as calcium channel blockers). Werapamil is a derivative of phenylalkylamine. Drugs of this group are designed to block calcium channels and structures responsible for the flow of calcium ions through the cell membrane. The preparation works by blocking the influx of calcium ions from the extracellular space into the heart muscle cells, including smooth muscle cells (blood vessel walls). The drug increases the intracellular concentration of calcium, which causes the contraction necessary to conduct electrical impulses. Werapamil is effective in treating supraventricular arrhythmias, it can also reduce the strength of the heart muscle.
isoptin affects the blood vessels, however, blocked calcium channels reduce the tension of the smooth muscles of the vessel walls by dilating them. People suffering from hypertension, using the preparation, will result in reduced blood pressure and reduced vascular resistance. As a result, the heart will use less energy (as a muscle) and will require less oxygen. The use of the drug also causes the expansion of the coronary arteries, thereby increasing the transport of oxygen to the heart muscle. The maximum concentration of verapamil in the blood occurs within 1 to 2 hours after oral administration.
Intended use
Lek Isoptin is used in the treatment of adults, children and adolescents in the case of:
- coronary heart disease (coronary artery disease), stable and unstable angina, vasospastic angina (Prinzmetal’s disease), angina after a heart attack without heart failure (when beta-blockers are not recommended)
- high blood pressure
- arrhythmias, paroxysmal supraventricular tachycardia, atrial flutter or fibrillation with rapid ventricular beats (except WPW or LGL syndrome)
Contraindications to use
In case of hypersensitivity to any component of the drug. Contraindications to be used in the case of:
- second or third degree atrioventricular block (does not apply to people with an implanted pacemaker)
- heart failure with a reduction in the ejection fraction below 35% and pulmonary wedge pressures greater than 20 mmHg
- atrial fibrillation or flutter with an additional conduction pathway (e.g. WPW or LGL syndrome)
- cardiogenic shock
- sick sinus syndrome (except for people with a pacemaker)
The drug should not be given to women pregnant and breastfeeding. The exception is the doctor’s decision about the necessity to administer it place in Isoptin.
Dosage of Isoptin
Lek Isoptin it is sold in the form of coated tablets for oral use. The capsules should be swallowed whole, without chewing or sucking, with a sufficient amount of water (preferably with or just after a meal).
The doctor will adjust dosage in each case individually. Do not change doses to your liking – increase or decrease, it can harm your health. When in doubt about dosing please consult your doctor. Most often adults and adolescents weighing more than 50 kg: dosage 120–480 mg daily (240–360 mg daily) in 3-4 doses divided. Dose the maximum is 480 mg daily.
children (only for arrhythmias):
- Children up to 6 years of age, 80-120 mg daily (in 2-3 divided doses).
- Children from 6 to 14 years of age, 80-360 mg daily (in 2-4 divided doses).
Be careful in the case of renal dysfunction in a patient. This also applies to people with impaired liver function. If the patient is taking other drugs or preparations in parallel, inform the attending physician.