Side Effects by Body System

General  -  Norvasc - Amlodipine is generally well-tolerated at dosages up to 10 mg per day. Most side effects reported were of mild or moderate severity and were dose-related. Headache and edema are the most common side effects.

Other -  Other side effects have included edema (up to 14.6%), flushing (up to 4.5%), fatigue (4.5%), and back pain (up to 2%). Allergic reaction, asthenia, hot flushes, malaise, pain, rigors, tinnitus, weight decrease, and weight gain have been reported in less than 1% but greater than 0.1% of patients. Cold and clammy skin and parosmia have been reported in less than 0.1% of patients. A single case of acute porphyria exacerbation has been associated with the use of amlodipine, and confirmed upon rechallenge in the same patient. Calcium channel blockers have been suggested as possibly unsafe in patients with this condition.

Cardiovascular  -  Cardiovascular side effects have included palpitation (up to 4.5%) and peripheral edema (2%). Peripheral edema may become a chronic problem, and may occur in up to 10% of patients who are receiving 10 mg doses. Arrhythmia (including ventricular tachycardia and atrial fibrillation), bradycardia, chest pain, hypotension, peripheral ischemia, postural dizziness, postural hypotension, syncope, tachycardia, and vasculitis have been reported in less than 1% but greater than 0.1% of patients. Cardiac failure, extrasystoles, and pulse irregularity have been reported in less than 0.1% of patients. Angina and myocardial infarction have occasionally been reported; however, these reactions could not be distinguished from coexisting disease states or medications. Worsened angina has been rarely associated with the use of amlodipine (as with other calcium channel blockers).

Recent data have shown that the use of amlodipine in patients with NYHA Class III or IV heart failure is not associated with worsened heart failure.

Nervous system

Nervous system side effects have included headache (7.3%), dizziness (up to 3.4%), and somnolence (1.6%). Hypoesthesia, paresthesia, peripheral neuropathy, tremor, and vertigo have been reported in less than 1% but greater than 0.1% of patients. Ataxia and migraine have been reported in less than 0.1% of patients. Myoclonus has been reported.

Gastrointestinal

Gastrointestinal side effects have included nausea (2.9%), dysphagia (up to 2%), and abdominal pain (1.6%). Anorexia, constipation, diarrhea, dry mouth, dyspepsia, flatulence, gingival hyperplasia, pancreatitis, and vomiting have been reported in less than 1% but greater than 0.1% of patients. Gastritis, increased appetite, loose stools, and taste perversion have been reported in less than 0.1% of patients. At least one case of amlodipine-associated dysgeusia has been reported and confirmed upon rechallenge.

Hematologic

A case study reports a 34-year-old woman with a history of chronic renal failure secondary to glomerulonephritis, who was started on amlodipine for uncontrolled hypertension. Three days later the patient developed severe thrombocytopenia. After discontinuation of the drug, the platelet count returned to normal.

Hematologic side effects have included leukopenia, purpura, and thrombocytopenia in less than 1% but greater than 0.1% of patients.

Hepatic

Hepatic side effects have included jaundice and hepatic enzyme elevations (mostly consistent with cholestasis or hepatitis) during postmarketing experience. In some instances, these cases were severe enough to require hospitalization.

Dermatologic

Dermatologic side effects have included rash and erythematous rash in up to 2% of patients and angioedema, erythema multiforme, increased sweating, maculopapular rash, and pruritus in less than 1% but greater than 0.1% of patients. Alopecia, dermatitis, skin discoloration, skin dryness, and urticaria have been reported in less than 0.1% of patients. Amlodipine-associated lichen planus and telangiectasia have been rarely reported.

Genitourinary

Genitourinary side effects have included micturition disorder, micturition frequency, and nocturia in less than 1% but greater than 0.1% of patients. Dysuria and polyuria have been reported in less than 0.1% of patients.

Hypersensitivity

Hypersensitivity side effects have included at least one case of erythema multiforme. Hypersensitivity reactions have rarely been reported, although experience with amlodipine is limited.

A 62-year-old man with hypertension and psoriasis developed erythema multiforme within three days after starting amlodipine. The rash resolved upon substitution with nifedipine.

Endocrine

In one case, a patient's gynecomastia resolved upon substitution of amlodipine with an unrelated antihypertensive agent.

Endocrine side effects have included gynecomastia during postmarketing experience.

Renal

Renal side effects have been reported rarely. At least one case of interstitial nephritis has been associated with amlodipine therapy.

 This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.