Amlodipine

Pronunciation: am-LOE-di-peen
Class: Calcium channel blocking agent

Trade Names

Norvasc
- Tablets 2.5 mg
- Tablets 5 mg
- Tablets 10 mg

Pharmacology

Inhibits movement of calcium ions across cell membrane in systemic and coronary vascular smooth muscle.

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Pharmacokinetics

Absorption

T _max is 6 to 12 h. Bioavailability is 64% to 90%. Steady state is reached after 7 to 8 days of consecutive daily dosing.

Distribution

About 93% is protein bound.

Metabolism

About 90% is converted to inactive metabolites in the liver.

Elimination

10% of the parent compound and 60% of the metabolites are excreted in the urine. Elimination is biphasic. Half-life is about 30 to 50 h.

Special Populations

Pharmacokinetics not significantly influenced.

Cl is decreased and AUC may increase about 40% to 60%.

Cl is decreased and AUC may increase about 40% to 60%.

Cl is decreased and AUC may increase about 40% to 60%.

Indications and Usage

Treatment of hypertension; treatment of chronic stable angina; or vasospastic (Prinzmetal or variant) angina; reduction of the risk of hospitalization caused by angina; reduction of the risk of coronary revascularization procedure in patients with recently documented coronary artery disease (CAD).

Contraindications

Standard considerations.

Dosage and Administration

PO Initial dose is 5 mg daily (max, 10 mg daily). 2.5 mg daily when adding amlodipine to other antihypertensive therapy.

PO 2.5 to 5 mg once daily.

PO 5 to 10 mg once daily.

PO 5 to 10 mg once daily.

PO Start with 5 mg once daily.

PO Initially 2.5 mg every day.

PO Start with 5 mg once daily.

PO Initially 2.5 mg every day.

General Advice

• Adjust dose as needed; titration should proceed over 7 to 14 days.
• Administer without regard to meals.

Storage/Stability

Store at 59° to 86°F.

Drug Interactions

Concurrent use may increase the plasma concentrations of amlodipine.

Pharmacologic effects of amlodipine may be increased.

Plasma concentrations of amlodipine may be increased.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Flushing, palpitations (5%).

CNS

Headache (7%); fatigue (5%); dizziness (3%); somnolence (2%).

GI

Nausea (3%); abdominal pain (2%).

Hepatic

Hepatic enzyme elevations, jaundice (postmaketing).

Miscellaneous

Edema (15%); gynecomastia (postmarketing).

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established in children younger than 6 yr of age.

Elderly

May require lower initial dose.

Hepatic Function

Use with caution in patients with severe hepatic impairment.

CV

Use with caution in patients with severe aortic stenosis or CHF.

Increased angina/MI

May occur when starting therapy or at the time of dosage increase.

Withdrawal

Abrupt withdrawal may cause increased frequency and duration of chest pain. Gradually taper dose if amlodipine is to be discontinued.

Overdosage

Symptoms

Hypotension, peripheral vasodilation, reflex tachycardia.

Patient Information

• Teach patient how to monitor pulse before taking medication. Tell patient not to take medication if pulse is less than 50 bpm and to contact health care provider.
• Explain to patient how to monitor BP daily.
• Instruct patient not to stop taking this medication suddenly because doing so can cause chest pain and MI.
• Inform patient that frequent follow-up appointments with health care provider are important to adjust medication dosage.
• Caution patient to avoid sudden position changes to prevent orthostatic hypotension.
• Instruct patient to take with or without food.
• Advise breast-feeding woman not to breast-feed.
• Advise patient that drug may cause drowsiness, and to use caution while driving or performing other tasks requiring mental alertness.

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