Amlodipine, sold under the brand name Norvasc among others, is a calcium channel blocker medication used to treat high blood pressure and coronary artery disease. It is taken by mouth.Common side effects include swelling, feeling tired, abdominal pain, and nausea. Serious side effects may include low blood pressure or heart attack. Whether use is safe during pregnancy or breastfeeding is unclear. When used by people with liver problems, and in elderly individuals, doses should be reduced. Amlodipine works partly by increasing the size of arteries. It is a long-acting calcium channel blocker of the dihydropyridine type.Amlodipine was patented in 1982, and approved for medical use in 1990. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. In 2020, it was the fifth most commonly prescribed medication in the United States, with more than 69 million prescriptions. Medical uses
Amlodipine is used in the management of hypertension and coronary artery disease in people with either stable angina (where chest pain occurs mostly after physical or emotional stress) or vasospastic angina (where it occurs in cycles) and without heart failure. It can be used as either monotherapy or combination therapy for the management of hypertension or coronary artery disease. Amlodipine can be administered to adults and children 6–17 years of age. Calcium channel blockers, including amlodipine, may provide greater protection against stroke than other classes of blood pressure-lowering medications.Amlodipine along with other calcium channel blockers are considered the first choice in the pharmacological management of Raynauds phenomenon.
Amlodipine is well absorbed by the oral route with a mean oral bioavailability around 60%; the half-life of amlodipine is about 30 h to 50 h, and steady-state plasma concentrations are achieved after 7 to 8 days of daily dosing. In the blood it has high plasma protein binding of 97.5%. Its long half-life and high bioavailability are largely in part of its high pKa (8.6); it is ionized at physiological pH, and thus can strongly attract proteins. It is slowly metabolized in the liver by CYP3A4, with its amine group being oxidized and its side ester chain being hydrolyzed, resulting in an inactive pyridine metabolite. Renal elimination is the major route of excretion with about 60% of an administered dose recovered in urine, largely as inactive pyridine metabolites. However, renal impairment does not significantly influence amlodipine elimination. 20-25% of the drug is excreted in the faeces. History
Pfizers patent protection on Norvasc lasted until 2007; total patent expiration occurred later in 2007. A number of generic versions are available. In the United Kingdom, tablets of amlodipine from different suppliers may contain different salts. The strength of the tablets is expressed in terms of amlodipine base, i.e., without the salts. Tablets containing different salts are therefore considered interchangeable. Fixed-dose combination of amlodipine and perindopril, an angiotensin converting enzyme inhibitor are also available.The medical form comes as besylate, mesylate or maleate. Veterinary use
Amlodipine is most often used to treat systemic hypertension in cats and dogs.