Serious adverse reactions are uncommon when verapamil hydrochloride therapy is initiated with upward dose titration within the recommended single and total daily dose. See WARNINGS for discussion of heart failure, hypotension, elevated liver enzymes, AV block, and rapid ventricular response. Reversible (upon discontinuation of verapamil) non-obstructive, paralytic ileus has been infrequently reported in association with the use of verapamil.
In clinical trials involving 285 hypertensive patients on verapamil hydrochloride extended-release for greater than one week the following adverse reactions were reported in greater than 1% of the patients:
In clinical trials of other formulations of verapamil hydrochloride (N=4,954) the following reactions have occurred at rates greater than 1%:
| (HR < 50/min)||1.4%|
|AV block|| |
| total 1º, 2º, 3º||1.2%|
| 2º and 3º||0.8%|
|Elevated Liver Enzymes|| |
| (see WARNINGS.)|| |
In clinical trials related to the control of ventricular response in digitalized patients who had atrial fibrillation or atrial flutter, ventricular rate below 50/min at rest occurred in 15% of patients and asymptomatic hypotension occurred in 5% of patients.
The following reactions, reported in 1% or less of patients, occurred under conditions (open trials, marketing experience) where a causal relationship is uncertain; they are listed to alert the physician to a possible relationship:
Cardiovascular: angina pectoris, atrioventricular dissociation, chest pain, claudication, myocardial infarction, palpitations, purpura (vasculitis), syncope.
Digestive System: diarrhea, dry mouth, gastrointestinal distress, gingival hyperplasia.
Hemic and Lymphatic: ecchymosis or bruising.
Nervous System: cerebrovascular accident, confusion, equilibrium disorders, insomnia, muscle cramps, paresthesia, psychotic symptoms, shakiness, somnolence.
Skin: arthralgia and rash, exanthema, hair loss, hyperkeratosis, maculae, sweating, urticaria, Stevens-Johnson Syndrome, erythema multiforme.
Special Senses: blurred vision, tinnitus.
Urogenital: gynecomastia, impotence, increased urination, spotty menstruation.
Treatment of Acute Cardiovascular Adverse Reactions
The frequency of cardiovascular adverse reactions which require therapy is rare; hence, experience with their treatment is limited. Whenever severe hypotension or complete AV block occurs following oral administration of verapamil, the appropriate emergency measures should be applied immediately, e.g., intravenously administered isoproterenol hydrochloride, norepinephrine, atropine (all in the usual doses), or calcium gluconate (10% solution). In patients with hypertrophic cardiomyopathy (IHSS), alpha-adrenergic agents (phenylephrine, metaraminol bitartrate or methoxamine) should be used to maintain blood pressure, and isoproterenol and levarterenol should be avoided. If further support is necessary, inotropic agents (dopamine or dobutamine) may be administered. Actual treatment and dosage should depend on the severity and the clinical situation and the judgment and experience of the treating physician.
REPORTS OF SUSPECTED VERAPAMIL SIDE EFFECTS / ADVERSE REACTIONS
Below is a sample of reports where side effects / adverse reactions may be related to Verapamil. The information is not vetted and should not be considered as verified clinical evidence.
Possible Verapamil side effects / adverse reactions in 49 year old female
Reported by a individual with unspecified qualification from United States on 2011-10-11
Patient: 49 year old female weighing 59.0 kg (129.8 pounds)
Reactions: Nausea, Cardiac Enzymes Increased, Prinzmetal Angina, Drug Interaction, Somnolence, Heart Rate Decreased, Chest Pain, Mitral Valve Incompetence, Blood Pressure Decreased, Vasospasm
Adverse event resulted in: hospitalization
Other drugs received by patient possibly interacting with the suspect drug:
Dosage: 180 mg, unk
Administration route: Oral
Dosage: 1 mg, unk
Dosage: 7 mg, unk
Indication: Smoking Cessation Therapy
Other drugs received by patient: Amantadine HCL; Acetaminophen and Hydrocodone Bitartrate; Gabapentin; Duloxetime Hydrochloride; Morphine Sulfate; Lorazepam; Natalizumab; Haloperidol; Fentanyl
Possible Verapamil side effects / adverse reactions in 88 year old male
Reported by a consumer/non-health professional from United States on 2011-10-13
Patient: 88 year old male
Reactions: Abnormal Behaviour, Gait Disturbance, Cerebrovascular Accident, Fall
Dosage: as needed.
Possible Verapamil side effects / adverse reactions in 58 year old female
Reported by a health professional (non-physician/pharmacist) from United States on 2011-10-18
Patient: 58 year old female
Reactions: Toxicity TO Various Agents, Blood Pressure Decreased, Cardiogenic Shock, Blood Glucose Abnormal, Hypokalaemia
Adverse event resulted in: hospitalization