Amlodipine dosage: finding the right dose for you

The BNF provides clear dosage guidance for amlodipine based on the clinical indication.

As a prescribing doctor, I tailor the dose to each patient's needs while following these evidence-based recommendations.

Hypertension:

• Starting dose: 5 mg once daily
• Maintenance dose: 5 to 10 mg once daily
• Dose titration: if blood pressure is not adequately controlled after 2 to 4 weeks, increase to 10 mg once daily

Angina (stable angina pectoris):

• Starting dose: 5 mg once daily
• Maintenance dose: 5 to 10 mg once daily
• Titrate according to symptom control and blood pressure response

Vasospastic (Prinzmetal's) angina:

• 5 to 10 mg once daily
• Higher doses may be needed due to the spastic component

NICE guideline NG136 (Hypertension in adults) recommends amlodipine as a first-line treatment option for hypertension, particularly in:

• Patients aged 55 and over
• Patients of Black African or Black Caribbean family origin (at any age)
• Patients who cannot tolerate ACE inhibitors or ARBs

Amlodipine is taken once daily and can be taken at any time of day, with or without food.

Its long half-life (30 to 50 hours) means that even if you miss a dose by a few hours, blood pressure control is maintained.

Consistency is key: choose a time that works for your routine and stick to it.

Older patients require careful dose selection for amlodipine. The BNF recommends starting at a lower dose due to altered pharmacokinetics and increased susceptibility to side effects.

Recommended approach:

• Starting dose: 2.5 mg once daily (half a 5 mg tablet or the 2.5 mg formulation where available)
• Titrate cautiously over 4 to 8 weeks
• Maximum dose: 10 mg once daily, but many elderly patients achieve adequate control at 5 mg

Why lower doses are needed:

• Reduced hepatic clearance means higher plasma drug levels at any given dose
• Increased sensitivity to blood pressure reduction, with greater risk of postural hypotension
• Higher prevalence of side effects including ankle oedema and dizziness
• Greater risk of falls, particularly in those with existing mobility problems or polypharmacy

Blood pressure targets in the elderly:

NICE NG136 provides age-specific targets:

• Under 80: clinic BP below 140/90 mmHg
• Over 80: clinic BP below 150/90 mmHg

I always advise my elderly patients to:

• Rise slowly from sitting or lying positions to avoid dizziness
• Monitor blood pressure at home if possible (automated devices are available on the NHS)
• Report any dizziness, light-headedness or falls promptly
• Keep a falls risk assessment up to date with their GP

Amlodipine is extensively metabolised by the liver (CYP3A4), and its clearance is significantly reduced in patients with hepatic impairment.

BNF recommendations:

• Start with 2.5 mg once daily
• Titrate cautiously based on blood pressure response and tolerability
• Maximum dose may need to be limited to 5 mg
• Half-life is prolonged, meaning steady-state levels take longer to achieve

Clinical considerations:

In patients with liver disease, I take the following approach:

1. Baseline assessment: check liver function tests before starting amlodipine
2. Low starting dose: always begin with 2.5 mg
3. Longer titration interval: wait at least 4 weeks before any dose increase
4. Monitor for side effects: the risk of peripheral oedema, hypotension and flushing is increased
5. Consider alternatives: if hepatic impairment is severe (Child-Pugh C), other antihypertensives that do not rely on hepatic metabolism may be preferable

Renal impairment:

In contrast to liver disease, no dose adjustment is required for renal impairment. Amlodipine is not significantly removed by dialysis, so it can be taken as normal by patients on haemodialysis.

This makes amlodipine a useful option in patients with chronic kidney disease, where many other antihypertensives require dose adjustment.

In many patients, single-drug therapy is insufficient to achieve target blood pressure, and NICE recommends a stepwise approach to combination treatment.

NICE NG136 step therapy:

• Step 1: monotherapy with amlodipine, an ACE inhibitor, or an ARB
• Step 2: combine amlodipine with an ACE inhibitor or ARB
• Step 3: add a thiazide-like diuretic (e.g. indapamide) to the combination
• Step 4 (resistant hypertension): consider adding spironolactone, an alpha-blocker or a beta-blocker

Common combinations with amlodipine:

• Amlodipine + ramipril: one of the most widely prescribed combinations. The ACE inhibitor helps counteract amlodipine-induced ankle swelling by dilating the venous side of the capillary bed
• Amlodipine + losartan: for patients who cannot tolerate ACE inhibitors (e.g. due to cough)
• Amlodipine + indapamide: triple therapy for resistant hypertension
• Amlodipine + atorvastatin: many patients with hypertension also require statin therapy for cardiovascular risk reduction. There is no significant interaction between these drugs

Fixed-dose combinations:

Several fixed-dose combination tablets are available on the NHS, which can simplify treatment and improve adherence:

• Amlodipine/valsartan (Exforge)
• Amlodipine/valsartan/hydrochlorothiazide (Exforge HCT)
• Amlodipine/olmesartan (Sevikar)

I often move to combination therapy early if the initial blood pressure is significantly above target (e.g.

systolic above 160 mmHg), as this achieves control faster and with lower doses of each individual drug.

Amlodipine's long half-life gives it a practical advantage over many other blood pressure medications: a missed dose does not cause a sudden loss of blood pressure control.

If you miss a dose:

• If you remember within 12 hours, take the missed dose as soon as possible
• If more than 12 hours have passed, skip the missed dose and take the next one at the usual time
• Never take a double dose to make up for a missed one

Practical tips for adherence:

• Set a daily phone alarm as a reminder
• Use a pill organiser box, especially if taking multiple medications
• Link taking your medication to an existing daily habit (e.g. brushing teeth, morning tea)
• Consider the NHS Electronic Repeat Dispensing service to ensure you never run out

Monitoring at home:

I encourage all my hypertensive patients to monitor their blood pressure at home using a validated automated device. NICE recommends:

• Measure twice daily (morning and evening) for at least 4 days, ideally 7 days, when assessing response to a new dose
• Take two readings each time, at least 1 minute apart, and record the second reading
• Home BP targets are lower than clinic targets: below 135/85 mmHg for most adults

Home monitoring data is invaluable at your NHS review appointments and helps your GP make accurate dose adjustments.