What is the recommended dosage of Amlodipine (calcium channel blocker) for an adult patient with hypertension (high blood pressure) or coronary artery disease, considering factors such as age, kidney function, and other comorbidities like heart failure?

Amlodipine Dosing for Hypertension and Coronary Artery Disease

Standard Adult Dosing

Start amlodipine at 5 mg once daily and increase to 10 mg once daily if blood pressure remains ≥130/80 mmHg after 2-6 weeks of treatment. 1, 2, 3

Initial Dose

• 5 mg once daily is the recommended starting dose for most adults with hypertension or coronary artery disease 1, 2, 3
• Administer at any convenient time of day to maximize adherence 1, 2
• The FDA-approved usual initial dose is 5 mg once daily for hypertension 3

Dose Titration

• Wait 7-14 days between dose adjustments per FDA labeling, though guidelines suggest 2-6 weeks is more appropriate for assessing full therapeutic effect 1, 2, 3
• Increase to 10 mg once daily (maximum dose) if blood pressure target is not achieved 1, 2, 3
• Titrate more rapidly if clinically warranted with frequent patient assessment 3

Blood Pressure Targets

• Target <130/80 mmHg for most adults with hypertension 4, 1, 2
• Confirm inadequate control with home blood pressure monitoring (≥135/85 mmHg) or 24-hour ambulatory monitoring (≥130/80 mmHg) before escalating therapy 1, 2

Special Populations Requiring Lower Starting Doses

Elderly, Small, or Fragile Patients

• Start at 2.5 mg once daily in elderly, small, or fragile patients 3
• This lower starting dose also applies when adding amlodipine to existing antihypertensive therapy 3

Hepatic Insufficiency

• Start at 2.5 mg once daily in patients with hepatic impairment 3
• For angina in patients with hepatic insufficiency, use the lower end of the dosing range (5 mg) 3

Renal Impairment

• No dose adjustment required for patients with chronic kidney disease due to amlodipine's low renal clearance (7 mL/min/mg) 1
• Amlodipine demonstrates renoprotective effects and does not worsen kidney function 1

Indication-Specific Dosing

Chronic Stable or Vasospastic Angina

• Recommended dose range: 5-10 mg once daily 3
• Most patients require 10 mg for adequate effect 3
• Use lower dose (5 mg) in elderly and patients with hepatic insufficiency 3

Coronary Artery Disease

• Recommended dose range: 5-10 mg once daily 3
• Clinical studies show the majority of patients required 10 mg once daily 3

Pediatric Dosing (Ages 6-17 Years)

• Start at 2.5 mg once daily for hypertension 1, 3
• Maximum dose is 5 mg once daily 1, 2, 3
• Doses exceeding 5 mg daily have not been studied in pediatric patients and are not recommended 2, 3

Combination Therapy Strategy

Consider adding a second agent rather than maximizing amlodipine to 10 mg if blood pressure remains uncontrolled after 4-6 weeks at 5 mg. 1

Preferred Combinations

• Amlodipine + ACE inhibitor or ARB 4, 1
• Amlodipine + thiazide-type diuretic 4, 1
• Single-pill combinations are strongly favored to improve adherence 4, 1
• For Black patients with hypertension, initial combination therapy is specifically recommended 4, 1

Combination Therapy for Severe Hypertension

• Use combination therapy when SBP ≥140 mmHg or DBP ≥90 mmHg and average BP is >20/10 mmHg above target 4
• Most adults with hypertension require two or more antihypertensive medications to achieve BP <130/80 mmHg 1

Critical Pitfalls to Avoid

Before Dose Escalation

• Check medication adherence first—non-adherence is the most common cause of apparent treatment failure 1, 2
• Measure blood pressure at trough (just before next dose) to ensure 24-hour control 1, 2
• Confirm elevated readings with home or ambulatory monitoring before escalating 1, 2

Drug Interactions

• Do not exceed 20 mg daily when coadministered with simvastatin or lovastatin due to increased statin exposure and myopathy risk 2
• Avoid combining two renin-angiotensin system blockers (ACE inhibitor + ARB) as this is potentially harmful 4

Monitoring Errors

• Do not assess treatment response before 2 weeks, as amlodipine has a slow onset due to its 40-60 hour elimination half-life 5
• Avoid premature dose escalation—wait at least 2-6 weeks to assess full therapeutic effect 1, 2

Monitoring Schedule

• Monthly visits until blood pressure target is achieved 1, 2
• Replace 30-day with 90-day refills once blood pressure is controlled 1, 2
• Consider telehealth strategies to augment office-based management 1

Common Side Effects (Dose-Dependent)

• Peripheral edema (10-30% at 10 mg dose, more common in women) 1, 6
• Headache, flushing, and constipation 1
• Side effects are more frequent at the 10 mg dose 1