What is amlodipine used for?

Amlodipine: Uses and Clinical Applications

Amlodipine is primarily indicated for the treatment of hypertension and angina pectoris, working as a calcium channel blocker that relaxes blood vessels to improve blood flow and reduce blood pressure. 1

Primary Indications

Hypertension

• Amlodipine is FDA-approved for treating hypertension, either as monotherapy or in combination with other antihypertensive agents 1
• Effectively lowers blood pressure by causing peripheral vasodilation through blocking calcium influx into vascular smooth muscle cells 2
• In the ALLHAT study, amlodipine was equally effective as chlorthalidone (a thiazide diuretic) in preventing coronary heart disease mortality and morbidity 3
• Provides consistent 24-hour blood pressure control with once-daily dosing due to its long half-life (36-45 hours) 2, 4

Coronary Artery Disease

Amlodipine is indicated for several forms of coronary artery disease:

1. Chronic Stable Angina

   • Used as monotherapy or in combination with other antianginal agents 1
   • Relieves angina by dilating coronary arteries and reducing cardiac workload 5

2. Vasospastic Angina (Prinzmetal's or Variant Angina)

   • Effective in treating confirmed or suspected vasospastic angina 1
   • Consistently effective in patients with vasospastic angina with no evidence of tolerance development 5

3. Angiographically Documented CAD

   • Reduces risk of hospitalization for angina and coronary revascularization procedures in patients with recently documented CAD without heart failure or ejection fraction <40% 1

Advantages of Amlodipine

• Long duration of action: Half-life of 36-45 hours allows for once-daily dosing 2, 4
• Gradual onset: Reduces incidence of reflex tachycardia and headache compared to other calcium channel blockers 5
• Safety in heart failure: Unlike non-dihydropyridine calcium channel blockers (verapamil, diltiazem), amlodipine can be safely used in patients with compensated heart failure 6
• Neutral metabolic profile: Does not cause adverse changes in serum glucose or lipid levels 2

Dosing Considerations

• Initial dose is typically 5 mg once daily, which can be increased to 10 mg daily if needed for symptom control 5
• Can be taken with or without food 1
• Once-daily dosing provides 24-hour efficacy with minimal fluctuation (20-25%) in plasma concentration between doses 4

Important Clinical Considerations

Drug Interactions

• No clinically important drug interactions have been widely reported 2
• When used with statins:
  • Amlodipine has minimal interaction with most statins 3
  • Doses of lovastatin or simvastatin >20 mg daily when coadministered with amlodipine are not recommended 3

Common Side Effects

• Peripheral edema (most common) 2
• Flushing 1
• Headache 5
• Dizziness 1

Special Populations

• Effective across diverse patient groups including elderly, young, men, women, black and non-black patients 3
• The ALLHAT study showed consistent results across these subgroups 3

Clinical Decision-Making Algorithm

1. For Hypertension:

   • Consider amlodipine as first-line therapy or as part of combination therapy
   • Start with 5 mg daily, titrate to 10 mg if needed
   • Monitor for peripheral edema, especially in elderly patients

2. For Angina:

   • Use as monotherapy or add to existing antianginal regimen
   • Particularly useful when beta-blockers are contraindicated or poorly tolerated
   • Effective for both stable and vasospastic angina

3. For Patients with Heart Failure:

   • Amlodipine is safe to use, unlike verapamil and diltiazem which should be avoided due to negative inotropic effects 6
   • Consider as part of combination therapy when blood pressure remains uncontrolled

Amlodipine's long half-life, consistent efficacy, and favorable side effect profile make it a valuable option for managing hypertension and various forms of angina, with the added benefit of being safe in patients with heart failure.