What Are the Dangers of Norvasc?

The brand-name prescription medication Norvasc contains amlodipine besylate, a type of medication known as a calcium channel blocker. The drug prevents calcium from entering your blood vessels, which then allows the vessels to relax or widen. As a result, Norvasc helps lower blood pressure and reduces strain on your heart. Despite its effectiveness in the treatment of hypertension, Norvasc poses a risk of side effects in some patients.

Cardiovascular and Circulatory

• One of the most common side effects of Norvasc is edema, or the accumulation of fluid under your skin, which occurs in as many as 15 percent of users, according to the U.S. National Library of Medicine. Edema occurs most commonly in a person's extremities, and though it is unpleasant it is not normally dangerous. More serious cardiovascular risks are possible while taking Norvasc, including arrhythmia (irregular heart rhythm), low blood pressure, loss of blood flow to your extremities, fainting and changes in heart rate. Norvasc use can result in heart attacks but rarely.

Neurological

• Headaches are another common symptom of Norvasc and occur in approximately eight percent of users, according to the U.S. National Library of Medicine. Dizziness and drowsiness occur often as well and affect as many as 1.6 percent of patients. Because of this, avoid driving or operating heavy machinery until you know how Norvasc affects you. Less common neurological side effects of Norvasc include nerve pain, tingling in your extremities, tremors or shaking, and vertigo.

Gastrointestinal

• Less than one percent of patients who take Norvasc experience gastrointestinal symptoms, reports the U.S. National Library of Medicine. Generally, these side effects pose no long-term health problems and include loss of appetite, constipation, indigestion, difficulty swallowing, diarrhea and swelling of gums. A more serious complication is gastritis, or inflammation of your stomach lining, which can result in gastrointestinal hemorrhages.

Hypersensitivity

• Some patients who take Norvasc develop hypersensitivity allergic reactions to the medication that range from minor skin hives to more severe complications. One possible allergic condition experienced by patients is angioedema, a severe and uncontrollable swelling of the eyes, lips, hands and throat. Angioedema can make it difficult to breathe and typically requires emergency medical attention.

Opthalmic and Aural

• Norvasc also has the potential to affect your eyes and ears, cautions the U.S. National Library of Medicine. Some patients report abnormal vision, double vision or eye pain, while others develop conjunctivitis or inflammation of the lining around the eyeball and eyelid. Tinnitus, or ringing in your ears, is another possible side effect.

Hematological

• Norvasc can cause deficiencies of certain blood cells, reports the U.S. National Library of Medicine. In some patients, this results in leukopenia, a deficiency of certain white blood cells that increases the risk of developing bacterial, viral or fungal infections. Another possible complication is thrombocytopenia, a shortage of the blood platelets necessary for platelets. Patients with the condition may notice their skin bruising easily or develop nosebleeds or bleeding of the gums.

Psychiatric

• Infrequently, patients experience psychiatric side effects from Norvasc, including decreased libido, insomnia, nervousness, depression, abnormal dreams and anxiety.