Verapamil Hydrochloride Injection

1. Verapamil hydrochloride is a calcium ion antagonist. It exerts its pharmacological effects by regulating the influx of calcium ions on the cell membranes of myocardial conduction cells, myocardial contractile cells, and arterial smooth muscle cells, but does not change the serum calcium concentration. 2. Verapamil hydrochloride dilates the main coronary arteries and arterioles in normal and ischemic parts of the heart, antagonizes spontaneous or ergonovine-induced coronary artery spasm, increases the delivery of myocardial oxygen to patients with coronary artery spasm, relieves and prevents coronary artery spasm; Verapamil reduces total peripheral resistance and reduces myocardial oxygen consumption. It can be used to treat variant angina and unstable angina. 3. Verapamil reduces calcium ion influx, prolongs the effective refractory period of the atrioventricular node, slows conduction, and can reduce the ventricular rate of patients with chronic atrial fibrillation and atrial flutter; it reduces the frequency of paroxysmal supraventricular tachycardia. Verapamil usually does not affect the normal sinus rate, but can cause sinus arrest or sinoatrial block in patients with sick sinus syndrome; Verapamil does not change the action potential or intraventricular conduction time of the normal atrium, but it reduces the amplitude, speed and conduction speed of the depolarization of the inhibited atrial fibers, which may shorten the forward effective refractory period of the additional bypass channel, accelerate the ventricular rate of patients with atrioventricular bypass combined with atrial flutter or atrial fibrillation, and even induce ventricular fibrillation. 4 Verapamil produces a blood pressure-lowering effect by reducing the vascular resistance of the systemic circulation, and generally does not cause postural hypotension or reflex tachycardia. 5 Verapamil reduces afterload, inhibits myocardial contraction, and can improve left ventricular diastolic function. In isometric or dynamic myocardial exercise, verapamil does not change the cardiac contractile function of patients with normal ventricular function. In patients with organic heart disease, the negative inotropic effect of verapamil can be offset by the effect of reducing afterload, and the cardiac index does not decrease. However, patients with severe left ventricular dysfunction (e.g., pulmonary wedge pressure greater than 20 mmHg or ejection fraction less than 30%), or patients taking beta-blockers or other myocardial depressant drugs, may experience worsening of cardiac function. 6 Animal experiments suggest that the local anesthetic effect of verapamil is 1.6 times that of procaine equimolar. The effect and dosage in humans are still unclear. Carcinogenicity, mutagenicity and reproductive toxicity Verapamil is not carcinogenic. The Ames test confirmed that verapamil is not mutagenic. Long-term use of verapamil ge;30mg/Kg/d by Beagle dogs resulted in lens-shaped and/or suture-shaped changes, and ge;62.5mg/Kg/d caused cataracts with obvious symptoms. There have been no reports of cataract formation in humans due to verapamil. No impairment of fertility was observed in female mice. The effect on human fertility is still unclear.

This product is a sterile aqueous solution of verapamil hydrochloride. The content of verapamil hydrochloride (C27H38N2O4.HCl) should be 93.0% to 107.0% of the labeled amount.

This product is a colorless clear liquid.

1. Cardioversion of rapid paroxysmal supraventricular tachycardia. Vagus nerve inhibition (such as Valsalva method) should be the first choice before applying verapamil. 2. Temporary control of ventricular rate in atrial flutter or atrial fibrillation. Except when atrial flutter or atrial fibrillation is combined with atrioventricular bypass pathway (preexcitation syndrome and LGL syndrome).

It must be injected slowly intravenously for at least 2 minutes under continuous ECG monitoring and blood pressure monitoring. This injection has no incompatibility with Ringer's solution, 5% glucose injection or sodium chloride injection. Because the optimal dosing interval for repeated intravenous administration cannot be determined, individualized treatment is required. The general starting dose is 5-10 mg (or 0.075-0.15 mg/Kg body weight), which is slowly injected intravenously for at least 2 minutes after dilution. If the initial reaction is not satisfactory, give another 5-10 mg or 0.15 mg/Kg body weight 15-30 minutes after the first dose. Intravenous drip administration, 5-10 mg per hour, added to sodium chloride injection or 5% glucose injection and dripped intravenously, the total amount per day should not exceed 50-100 mg.

Adverse reactions with an incidence of 1% include: symptomatic hypotension (1.5%), bradycardia (1.2%), dizziness (1.2%), headache (1.2%), rash (1.2%), and severe tachycardia (1.0%). Adverse reactions with an incidence of 1% include: nausea (0.9%), abdominal discomfort (0.6%), epilepsy during intravenous administration, depression, drowsiness, rotary nystagmus, vertigo, sweating, bronchospasm/laryngeal spasm with itching and urticaria in hypersensitive patients, respiratory failure, etc.

1 Severe congestive heart failure (except those secondary to supraventricular tachycardia and can be corrected by verapamil). 2 Severe hypotension (systolic blood pressure less than 90 mmHg) or cardiogenic shock 3 Sick sinus syndrome (except patients with installed and functioning cardiac pacemakers) 4 II or III degree atrioventricular block (except patients with installed and functioning cardiac pacemakers) 5 Patients with atrial flutter or atrial fibrillation combined with atrioventricular bypass pathways 6 Patients who have been treated with beta-blockers or digitalis poisoning. 7 Ventricular tachycardia. Intravenous verapamil in patients with ventricular tachycardia with widened QRS (ge; 0.12 seconds) may lead to significant hemodynamic deterioration and ventricular fibrillation. Wide QRS tachycardia must be identified as supraventricular or ventricular before medication. 8 Patients with known allergy to verapamil hydrochloride.

1. Phenobarbital may increase the clearance of verapamil. 2. Ramifenamide may significantly reduce the bioavailability of verapamil. 3. Acute studies of healthy volunteers taking cimetidine have mixed results, with the clearance of verapamil decreasing or remaining unchanged. 4. Combination with beta-blockers may enhance the inhibitory effect on atrioventricular conduction. 5. When used in combination with other antihypertensive drugs (such as vasodilators, diuretics, etc.), the antihypertensive effects are additive, and patients receiving such combined treatments should be appropriately monitored. 6. Combination with amiodarone may increase cardiac toxicity. 7. Verapamil may increase the blood concentrations of carbamazepine and cyclosporine. 8. There are reports that verapamil increases the sensitivity of patients to lithium (neurotoxicity), and close monitoring is required when the two drugs are used together. 9. Animal experiments suggest that inhaled anesthetics inhibit cardiovascular activity by reducing calcium influx. When used simultaneously with calcium ion antagonists such as verapamil, the doses of the two drugs need to be carefully adjusted to avoid excessive cardiac inhibition. 10. Avoid using disopyramide at the same time. 11 Neuromuscular blockers: Clinical data and animal experimental studies have shown that verapamil may enhance the activity of neuromuscular blockers. When used in combination, the dose of verapamil or neuromuscular blocker should be reduced. 12 Dantrolene: Two animal experimental studies have shown that the concomitant use of the two drugs can lead to cardiovascular collapse.

Keep in a light-proof and airtight container.

2ml:5mg