Verapamil, the active substance of the drug, blocks transmembrane calcium entry into cardiomyocytes and vascular smooth muscle cells. It directly reduces myocardial oxygen requirement by affecting energy consumption by the myocardial cells and decreased afterload.
Paroxysmal supraventricular tachycardia, atrial flutter/fibrillation (not including Wolff–Parkinson–White syndrome (WPW)).
Unstable angina in patients for whom nitrates and/or β˗blockers are contraindicated, including vasospastic angina, Prinzmetal's variant angina.
Arterial hypertension; hypertensive crisis.
In children: in paroxysmal supraventricular tachycardia.
Intravenous administration should be performed slowly (in no less than 2 minutes) under observation of medical professionals, with ECG and blood pressure monitoring. Patients who have received verapamil intravenously as the initial treatment of unstable angina should be switched to oral verapamil as soon as possible.
The recommended doses for adults and adolescents with a body weight of over 50 kg are: the initial dose is 5 mg of verapamil hydrochloride (corresponding to 2 mL of Verapamil-Darnitsa, solution for injection); if necessary, another 5 mg can be injected after 5–10 minutes. If necessary, further administration by intravenous drip of 5–10 mg of Verapamil-Darnitsa diluted in 0.9% sodium chloride solution is possible over 1 hour; another diluent can be 5% glucose with pH < 6.5. The average daily intramuscular dose should not exceed 100 mg of verapamil hydrochloride.
In patients with impaired liver function, the bioavailability of verapamil increases significantly. In such cases, the dose should be determined with caution.