Norvasc
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Norvasc".

Amlodipine
Systematic (IUPAC) name
3-ethyl-5-methyl-2-(2-aminoethoxymethyl)-4-(2- chlorophenyl)-1,4-dihydro-6-methyl-3,5- pyridinedicarboxylate
Identifiers
CAS number	88150-42-9
ATC code	C08CA01
PubChem	2162
DrugBank	APRD00520
ChemSpider	2077
Chemical data
Formula	C20H25ClN2O5
Mol. mass	408.879 g/mol
SMILES	eMolecules & PubChem
Pharmacokinetic data
Bioavailability	64 to 90%
Metabolism	Hepatic
Half life	30 to 50 hours
Excretion	Renal
Therapeutic considerations
Pregnancy cat.	C(AU) C(US)
Legal status	POM(UK) ℞-only(US)
Routes	Oral (tablets)

Amlodipine (as besylate, mesylate or maleate) is a long-acting calcium channel blocker (dihydropyridine) 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 peripheral resistance and hence reducing blood pressure; in angina it increases blood flow to the heart muscle.

Amlodipine is marketed as Dailyvasc in the Philippines by Xeno Pharmaceuticals, and by Pfizer as Norvasc in North America and Australia and as Istin in the United Kingdom. Generic brands (sold under names such as Perivasc in Australia) are also available.

Indications

• hypertension
• prophylaxis of angina

Cautions

• hepatic impairment
• pregnancy

Contraindications

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

Side effects

Some side effects¹ of the use of amlodipine may be:

• Very often: peripheral oedema (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 - 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: 5 or 10 mg once daily (initial treatment can start as low a 2.5 mg per day).

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.

Drug Metabolism and Excretion

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

Patent loss

Pfizer patent protection on Norvasc lasted until 2007. A number of generic versions are now available. Total patent expiration occurred later in 2007.²

References

1. ^ Source: Sandoz product information sheet
2. ^ Kennedy, Val Brickates (2007-03-22). "Pfizer loses court ruling on Norvasc patent", MarketWatch. 

External links

• Norvasc
• Istin - Summary of Product Characteristics from the electronic Medicines Compendium