What is the appropriate initial dose and administration of Amlodipine (calcium channel blocker) for treating hypertension or angina?

Amlodipine Initial Dosing for Hypertension and Angina

For adults with hypertension, start amlodipine at 5 mg once daily, with the option to titrate to 10 mg once daily after 7-14 days if blood pressure goals are not met; for small, fragile, elderly patients, or those with hepatic insufficiency, start at 2.5 mg once daily. 1

Standard Dosing for Hypertension

• The FDA-approved initial dose for hypertension is 5 mg once daily, with a maximum dose of 10 mg once daily 1
• Titration should occur after 7-14 days between dose adjustments, though more rapid titration is acceptable if clinically warranted with frequent patient assessment 1
• Wait at least 6 weeks at the 5 mg dose before increasing to 10 mg, as studies show no advantage to early dose escalation—84% of patients achieve diastolic BP ≤90 mmHg on 5 mg alone 2
• Blood pressure reduction occurs steadily until week 6 of treatment, making earlier dose increases unnecessary 2

Special Population Dosing

• Start at 2.5 mg once daily for:

  • Small or fragile patients 1
  • Elderly patients 1
  • Patients with hepatic insufficiency 1
  • When adding amlodipine to existing antihypertensive therapy 1

• For patients receiving bevacizumab who develop hypertension, 5 mg daily is the recommended initial dose for antihypertensive-naive patients 3

Dosing for Angina

• For chronic stable angina or vasospastic angina, the recommended dose range is 5-10 mg once daily 1
• Most patients with angina require 10 mg daily for adequate symptom control 1, 4
• In elderly patients and those with hepatic insufficiency, use the lower 5 mg dose initially 1
• The starting regimen is 5 mg daily, increased to 10 mg daily after 2 weeks if patients continue to have even a single anginal attack per week 5

Dosing for Coronary Artery Disease

• The recommended dose range for documented coronary artery disease is 5-10 mg once daily 1
• Clinical studies demonstrate that the majority of CAD patients required 10 mg for optimal cardiovascular protection 1

Timing of Administration

• Administer amlodipine in the morning rather than evening 6
• Morning dosing produces greater nocturnal BP fall (9.8/7.4 mmHg vs 6.7/5.4 mmHg, p<0.01/0.05) and better 24-hour BP control compared to evening dosing 6
• Evening dosing results in significantly higher 24-hour diastolic BP load (11.0% vs 6.5%, p<0.05) and night-time BP load 6
• Preferential bedtime dosing of antihypertensives is not recommended based on recent trial data 7

Pediatric Dosing (Ages 6-17 Years)

• The effective antihypertensive dose is 2.5-5 mg once daily 1
• Doses exceeding 5 mg daily have not been studied in pediatric patients 1

Clinical Efficacy Timeline

• Amlodipine provides 24-hour blood pressure control with once-daily dosing 8
• Mean daytime BP reduction: from 165/103 to 147/89 mmHg (p<0.05) 8
• Mean nighttime BP reduction: from 137/79 to 121/69 mmHg (p<0.05) 8
• The drug maintains the normal circadian BP pattern without causing reflex tachycardia 8

Role in Combination Therapy

• Amlodipine is recommended as a first-line agent, particularly in combination with RAS blockers (ACE inhibitors or ARBs) and thiazide diuretics 7, 9
• For patients with diabetes and established coronary artery disease, combine amlodipine with ACE inhibitors or ARBs as first-line therapy 7
• In resistant hypertension (BP ≥140/90 mmHg on three drugs including a diuretic), amlodipine is often included in the multi-drug regimen 3

Common Pitfalls

• Avoid rapid-release, short-acting dihydropyridines (like nifedipine) without concurrent β-blockade in acute coronary syndromes, as they increase adverse outcomes 7
• Ankle edema occurs in approximately 10% of patients but is generally tolerable and may resolve with continued therapy 5
• Do not increase the dose before 6 weeks of treatment at 5 mg, as this provides no additional benefit 2
• Amlodipine's gradual absorption produces gradual vasodilation, reducing side effects like reflex tachycardia and headache compared to other calcium antagonists 4

Safety Profile

• Amlodipine has been proven safe in multiple large trials, with no increased risk of cancer, gastrointestinal bleeding, or cardiovascular mortality 7
• In heart failure patients (NYHA Class III-IV), amlodipine showed no adverse effect on mortality or cardiac morbidity, though more pulmonary edema was reported 1
• The drug can be safely used in patients with left ventricular dysfunction (LVEF ≥40%) and documented coronary artery disease 1