Amlodipine

Amlodipine

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Systematic (IUPAC) name
(RS)-3-ethyl 5-methyl 2-[(2-aminoethoxy)methyl]-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate
Clinical data
Pregnancy category	AU: C US: C (Risk not ruled out)
Routes of administration	Oral (tablets)
Legal status
Legal status	UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Bioavailability	64 to 90%
Metabolism	HepaticNikhil and Nilesh filed a patent on amlodipine
Biological half-life	30 to 50 hours
Excretion	Renal
Identifiers
CAS Number	88150-42-9
ATC code	C08CA01 (WHO)
PubChem	CID 2162
DrugBank	APRD00520
ChemSpider	2077
Chemical data
Formula	C20H25ClN2O5
Molar mass	408.879 g/mol[[]]
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Amlodipine (as besylate, mesylate or maleate) is a long-acting calcium channel blocker (dihydropyridine class) used as an anti-hypertensive and in the treatment of angina. Like other calcium channel blockers, amlodipine acts by relaxing the smooth muscle in the arterial wall, decreasing total peripheral resistance and hence reducing blood pressure; in angina it increases blood flow to the heart muscle.

Indications

• Hypertension
• Angina pectoris

Cautions

• hepatic impairment
• pregnancy

Contraindications

• cardiogenic shock
• unstable angina
• aortic stenosis
• breast feeding

Amlodipine causes vasodilatation, which in patients with severe aortic stenosis, can result in reduced cardiac output.

There is not absolute consensus about the contraindication, because if the patient has hypertension, his stenosis cannot be very severe, otherwise he would not have sufficient output to allow hypertension.

Side effects

Some side effects of the use of amlodipine may be:

• Very often: peripheral edema (feet and ankles) - in 1 of 10 users
• Often: dizziness; palpitations; muscle-, stomach- or headache; dyspepsia; nausea - in 1 in 100 users
• Sometimes: blood disorders, development of breasts in men (gynecomastia), impotence, depression, insomnia, tachycardia, gingival enlargement - in 1 in 1,000 users,
• Rarely: erratic behavior, hepatitis, jaundice - in 1 in 10,000 users
• Very rarely: hyperglycemia, tremor, Stevens-Johnson syndrome - in 1 in 100,000 users

Dose

• Hypertension or angina: 2.5 to 10 mg once daily (initial treatment can start as low as 2.5 mg per day, titrate up to 10 mg/day as necessary).

Salts

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 salt. Tablets containing different salts are therefore considered interchangeable.

The efficacy and tolerability of a fixed-dose combination of amlodipine 5 mg and perindopril 4 mg, an angiotensin converting enzyme (ACE) inhibitor, have recently been confirmed in a prospective, observational multicentre trial of 1250 hypertensive patients.

Drug metabolism and excretion

Amlodipine is almost entirely metabolised to inactive metabolites. 10% of the parent substance and 60% of the metabolites are excreted in urine.

Stereoisomerism

File:(±)-Amlodipine Enantiomers Structural Formulae.png

Enantiomers of amlodipine

Amlodipine is a chiral calcium antagonist, currently on the market and in therapeutic use as a racemate [1:1 mixture of (R)-(+)- and (S)-(–)-amlodipine]. A method for the semi-preparative chromatographic purification of the enantiomers (S)-(–)-amlodipine and (R)-(+)-amlodipine has been reported.

Patent loss

Pfizer patent protection on Norvasc lasted until 2007. Total patent expiration occurred later in 2007. A number of generic versions are available.

Brand names

Amlodipine is marketed as:

• Norvasc by Pfizer in North America, some European countries, China, and Japan
• Norvasc and Perivasc in Australia
• Istin in the United Kingdom and Ireland
• Agen by Zentiva in the Czech Republic
• Amdipin in Colombia by Laboratorios Lafrancol
• Amlodine by Dainippon Sumitomo Pharmaceuticals in Japan, and in Philippines by Westfield Pharmaceuticals, a division of InnoGen
• Amdepin by Cadila Pharmaceuticals in India
• Dailyvasc by Xeno Pharmaceuticals
• Aken in Mexico by Kendrick Farmaceutica
• Lopin in Bangladesh by Edruc Ltd
• Amlopine in Thailand by Berlin (Thailand) Pharmaceutical Industry Co Ltd
• Amcard in Bangladesh by Apex Pharma Ltd
• Hipril is a combination of lisinopril with amlodipine (5 mg each) in India by velavan

See also

• Amlodipine/benazepril

External links

• Norvasc
• Istin - Summary of Product Characteristics from the electronic Medicines Compendium
• U.S. National Library of Medicine: Drug Information Portal - Amlodipine

ar:أملوديبين uk:Амлодипін