What is the recommended dosage of amlodipine (calcium channel blocker) for elderly patients with impaired renal function and a history of cardiovascular conditions?

Amlodipine Dosing for Elderly Patients

Start amlodipine at 2.5 mg once daily in elderly patients, particularly those with impaired renal function and cardiovascular disease, then titrate gradually to 5 mg after 7-14 days if blood pressure remains uncontrolled and the medication is well-tolerated. 1, 2

Initial Dosing Strategy

• Begin with 2.5 mg once daily in elderly patients (≥65 years), especially those who are small, fragile, or have hepatic insufficiency 1
• The European Society of Cardiology emphasizes that initial doses and subsequent titration should be more gradual in elderly patients due to greater risk of adverse effects, particularly in very old and frail subjects 2, 3
• Elderly patients have decreased clearance of amlodipine with a resulting 40-60% increase in drug exposure (AUC), necessitating lower starting doses 1
• The elimination half-life is prolonged in elderly patients (64 hours vs. 48 hours in younger patients), contributing to higher steady-state concentrations 4

Titration Protocol

• Wait 7-14 days between dose adjustments to allow adequate time to assess response and tolerability 1, 5
• If blood pressure remains above target after 2-6 weeks at 2.5 mg, increase to 5 mg once daily 5
• The maximum dose is 10 mg once daily, though most elderly patients achieve adequate control at 5 mg 1
• Titrate more rapidly only if clinically warranted and the patient can be assessed frequently 1

Blood Pressure Targets and Monitoring

• Target blood pressure is <140/90 mmHg for most elderly patients, with individualization based on frailty status 3
• For debilitated or frail persons ≥80 years of age, a systolic blood pressure goal <150 mmHg is reasonable 3
• Monitor both sitting and standing blood pressure at every visit to detect orthostatic hypotension, which is more common in elderly patients 2, 6
• Confirm inadequate control with home blood pressure monitoring (≥135/85 mmHg) or 24-hour ambulatory monitoring (≥130/80 mmHg) before escalating therapy 5
• Measure blood pressure at trough (just before next dose) to ensure 24-hour control 5

Special Considerations for Renal Impairment

• No dose adjustment is required for renal impairment, as amlodipine pharmacokinetics are not significantly influenced by renal function 7, 1
• Amlodipine is 90% metabolized hepatically to inactive metabolites, with only 10% excreted unchanged in urine 1
• Studies demonstrate that amlodipine at 2.5-5 mg daily effectively lowers blood pressure in hypertensive patients with renal dysfunction without aggravating renal function 8
• The elimination half-life remains approximately 50 hours regardless of renal function, and accumulation does not occur with once-daily dosing 7

Cardiovascular Disease Considerations

• For elderly patients with coronary artery disease, the recommended dose range is 5-10 mg once daily, with lower doses (5 mg) suggested initially 1
• For chronic stable or vasospastic angina, start with 5 mg daily in elderly patients, though most will require 10 mg for adequate effect 1
• Calcium channel blockers like amlodipine cause greater antihypertensive effects in elderly patients due to decreased baroreceptor response and age-related increases in drug exposure 3

Combination Therapy Strategy

• Add a second agent (ACE inhibitor/ARB or thiazide diuretic) rather than maximizing amlodipine if blood pressure control is inadequate after 4-6 weeks at 5 mg 5, 3
• The ACCOMPLISH trial demonstrated efficacy of benazepril-amlodipine combination in patients ≥65 years with similar relative benefit as the overall study population 3
• Avoid combining amlodipine with beta-blockers initially without careful monitoring, as they may act synergistically to depress cardiac function 2

Safety Monitoring and Adverse Effects

• Peripheral edema is the most common side effect, occurring more frequently in elderly patients; starting at 2.5 mg helps minimize this 2
• Monitor for orthostatic hypotension, dizziness, headache, flushing, and falls—all more common in elderly patients 3
• Dihydropyridine calcium channel blockers can worsen orthostatic hypotension through peripheral vasodilation, particularly problematic in elderly patients 6
• Check medication adherence before escalating dose, as non-adherence is the most common cause of apparent treatment failure 5, 6

Common Pitfalls to Avoid

• Avoid immediate-release nifedipine due to risk of hypotension and heart failure 3
• Do not start at 5 mg in frail elderly patients—use 2.5 mg to minimize adverse effects 1, 2
• Do not escalate dose before 7-14 days unless clinically urgent with frequent monitoring 1
• Avoid excessive diuresis if adding diuretics in elderly patients with heart failure with preserved ejection fraction 3