Verapamil hydrochloride injection is contraindicated in:
1. Severe hypotension or cardiogenic shock.
2. Second- or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker).
3. Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker).
4. Severe congestive heart failure (unless secondary to a supraventricular tachycardia amenable to verapamil therapy).
5. Patients receiving intravenous beta-adrenergic blocking drugs (e.g., propranolol). Intravenous verapamil and intravenous beta-adrenergic blocking drugs should not be administered in close proximity to each other (within a few hours), since both may have a depressant effect on myocardial contractility and AV conduction.
6. Patients with atrial flutter or atrial fibrillation and an accessory bypass tract (e.g., Wolff- Parkinson-White, Lown-Ganong-Levine syndromes) are at risk to develop ventricular tachyarrhythmia including ventricular fibrillation if verapamil is administered. Therefore, the use of verapamil in these patients is contraindicated.
7. Ventricular tachycardia: Administration of intravenous verapamil to patients with wide-complex ventricular tachycardia (QRS ≥ 0.12 sec) can result in marked hemodynamic deterioration and ventricular fibrillation. Proper pretherapy diagnosis and differentiation from wide-complex supraventricular tachycardia is imperative in the emergency room setting.
8. Known hypersensitivity to verapamil hydrochloride.