Amlodipine inhibits calcium ion influx across cell membranes, with a greater effect on vascular smooth muscle cells. This causes vasodilation and a reduction in peripheral vascular resistance, thus lowering blood pressure. Its effects on cardiac muscle also prevent excessive constriction in the coronary arteries.Negative inotropic effects can be detected in vitro, but such effects have not been seen in intact animals at therapeutic doses. Among the two stereoisomers [R(+), S(–)], the (–) isomer has been reported to be more active than the (+) isomer. Serum calcium concentration is not affected by amlodipine. And it specifically inhibits the currents of L-type Cav1.3 channels in the zona glomerulosa of the adrenal gland.The mechanisms by which amlodipine relieves angina are:

Stable angina: amlodipine reduces the total peripheral resistance (afterload) against which the heart works and reduces the rate pressure product, thereby lowering myocardial oxygen demand, at any given level of exercise. Variant angina: amlodipine blocks spasm of the coronary arteries and restores blood flow in coronary arteries and arterioles in response to calcium, potassium, epinephrine, serotonin, and thromboxane A2 analog in experimental animal models and in human coronary vessels in vitro.Amlodipine has additionally been found to act as an antagonist of the mineralocorticoid receptor, or as an antimineralocorticoid. Pharmacokinetics
Amlodipine has been studied in healthy volunteers following oral administration of 14C-labelled drug.
Amlodipine-association edema can be avoided by adding ACE inhibitors or angiotensin II receptor antagonist. Of the other dose-dependent side effects, palpitations (4.5% at 10 mg vs. 0.6% in placebos) and flushing (2.6% vs. 0%) occurred more often in women; dizziness (3.4% vs. 1.5%) had no sex bias.Common but not dose-related adverse effects are fatigue (4.5% vs. 2.8% with a placebo), nausea (2.9% vs. 1.9%), abdominal pain (1.6% vs. 0.3%), and drowsiness (1.4% vs. 0.6%). Side effects occurring less than 1% of the time include: blood disorders, impotence, depression, peripheral neuropathy, insomnia, tachycardia, gingival enlargement, hepatitis, and jaundice.Amlodipine-associated gingival overgrowth is a relatively common side effect with exposure to amlodipine. Poor dental health and buildup of dental plaque are risk factors.Amlodipine may increase the risk of worsening angina or acute myocardium infarction, especially in those with severe obstructive coronary artery disease, upon dosage initiation or increase. However, depending on the situation, Amlodipine inhibits constriction and restores blood flow in coronary arteries as a result of its property that works directly on vascular smooth muscle causing reduction in peripheral vascular resistance and consequent reduction in blood pressure. Overdose
Although rare, amlodipine overdose toxicity can result in widening of blood vessels, severe low blood pressure, and fast heart rate. Toxicity is generally managed with fluid replacement monitoring ECG results, vital signs, respiratory system function, glucose levels, kidney function, electrolyte levels, and urine output. Vasopressors are also administered when low blood pressure is not alleviated by fluid resuscitation. Interactions
Several drugs interact with amlodipine to increase its levels in the body.