Brands, Medical Use, Clinical Data
Drug Category
- Vasodilator Agents
- Antianginals
- Antihypertensive Agents
- Calcium Channel Blockers
Dosage Forms
- Tablets (equivalent to 2.5, 5 and 10 mg)
Brands / Synonyms
Amlobenz; Amlocard; Amlodipine and Atorvastatin; Amlodipine Benzenesulfonate; Amlodipine Besilate; Amlodipine Besylate; Amlodipine Free Base; Amlodipino [Spanish]; Amlodipinum [Latin]; Amlodis; Amturnide; Amvaz; Azor; Caduet; Coroval; Exforge; Exforge HCT; Lipinox; Lotrel; Norvasc; Norvasc
; Tekamlo; Tribenzor
Indications
For the treatment of hypertension, chronic stable angina and confirmed or suspected vasospastic angina.
Pharmacology
Amlodipine, a calcium-channel blocker, is used alone or with benazepril, an angiotensin-converting enzyme inhibitor, to treat hypertension, chronic stable angina pectoris, and Prinzmetal's variant angina. Amlodipine is similar to the peripheral vasodilator nifedipine and other members of the dihydropyridine class.
Mechanism of Action
Amlodipine is a calcium channel blocking agent. It inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes. The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload. Another possible mechanism is that amlodipine inhibits vascular smooth muscle carbonic anhydrase I activity with consecutive pH increase which may be involved in intracelluar calcium influx through calcium channels.
Absorption
Amlodipine is slowly and almost completely absorbed from the gastrointestinal tract.
Toxicity
Gross overdosage could result in excessive peripheral vasodilatation and possibly reflex tachycardia. Marked and probably prolonged systemic hypotension up to an including shock with fatal outcome have been reported.
Biotrnasformation / Drug Metabolism
Hepatic.
Contraindications
NORVASC is contraindicated in patients with known sensitivity to amlodipine.
Drug Interactions
In vitro data indicate that NORVASC has no effect on the human plasma protein binding of digoxin,
phenytoin, warfarin, and indomethacin.
Effect of other agents on NORVASC.
CIMETIDINE: Co-administration of NORVASC with cimetidine did not alter the pharmacokinetics of NORVASC.
GRAPEFRUIT JUICE: Co-administration of 240 mL of grapefruit juice with a single oral dose of amlodipine 10
mg in 20 healthy volunteers had no significant effect on the pharmacokinetics of amlodipine.
MAALOX (antacid): Co-administration of the antacid Maalox with a single dose of NORVASC had no significant
effect on the pharmacokinetics of NORVASC.
SILDENAFIL: A single 100 mg dose of sildenafil (ViagraÒ) in subjects with
essential hypertension had no effect on the pharmacokinetic parameters of NORVASC. When NORVASC and sildenafil were
used in combination, each agent independently exerted its own blood pressure lowering effect.
Effect of NORVASC on other agents.
ATORVASTATIN: Co-administration of multiple 10 mg doses of NORVASC with 80 mg of atorvastatin resulted in
no significant change in the steady state pharmacokinetic parameters of atorvastatin.
DIGOXIN: Co-administration of NORVASC with digoxin did not change serum digoxin levels or digoxin renal
clearance in normal volunteers.
ETHANOL (alcohol): Single and multiple 10 mg doses of NORVASC had no significant effect on the
pharmacokinetics of ethanol.
WARFARIN: Co-administration of NORVASC with warfarin did not change the warfarin prothrombin response
time.
In clinical trials, NORVASC has been safely administered with thiazide diuretics, beta-blockers,
angiotensin-converting enzyme inhibitors, long-acting nitrates, sublingual nitroglycerin, digoxin, warfarin,
non-steroidal anti-inflammatory drugs, antibiotics, and oral hypoglycemic drugs.
Drug/Laboratory Test Interactions: None known.
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