Amlodipine

Dihydropyridine

 

Attributes

Our Records are Incomplete for Drug Attributes

 

Other Contra-Indication

Do not drink grapefruit juice daily as this raises the levels of amlodipine in the blood

This drug is contra-indicated in patients with a history of hypersensitivity reactions to it

 

Class Contra-Indication

Our Records are Incomplete for Drug Class Contra-Indications

Amlodipine

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 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, Australia and some European countries, and as Istin in the United Kingdom and Ireland. 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 effects^[1] 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 - 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 or 10 mg once daily (initial treatment can start as low as 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.

The efficacy and tolerability of a fixed-dose combination of amlodipine 5mg and perindopril 4mg, an angiotensin converting enzyme (ACE) inhibitor, has recently been confirmed in a prospective, observational multicenter trial 1250 hypertensive patients.^[2]

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. Total patent expiration occurred later in 2007^[3]. A number of generic versions are now available.

References

1. ^ Source: Sandoz product information sheet
2. ^ Bahl VK, Jadhav UM, Thacker HP. Management of Hypertension with the Fixed Combination of Perindopril and Amlodipine in Daily Clinical Practice: Results from the STRONG Prospective, Observational, Multicenter Study. American Journal of Cardiovascular Drugs May 22, 2009; 9 (3): 135-42 Link text
3. ^ Kennedy, Val Brickates (2007-03-22). "Pfizer loses court ruling on Norvasc patent