Amlodipine 💊
Related Subjects:
|Calcium Channel Blockers
|Nifedipine
|Felodipine
|Essential Hypertension
|Simvastatin
🦵 The commonest problem with amlodipine is ankle oedema. It is dose-related and caused by pre-capillary vasodilation, so it responds poorly to diuretics or leg elevation and may need a dose reduction, a switch, or the addition of an ACE inhibitor/ARB.
📖 About
- Long-acting dihydropyridine calcium channel blocker (CCB), given once daily.
- First-line for hypertension in people of Black African or African–Caribbean origin and in those aged 55 or over without diabetes (NICE NG136).
- Always check the BNF for up-to-date prescribing information.
⚙️ Mode of Action
- Blocks L-type calcium channels in vascular smooth muscle → arteriolar vasodilation → ↓ peripheral resistance and BP.
- Predominantly vascular; negligible negative inotropic effect at therapeutic doses, so it can be used in heart failure with reduced EF if a CCB is needed (unlike diltiazem/verapamil).
- Coronary vasodilation → anti-anginal.
🎯 Indications
- Hypertension (NICE NG136 step 1 or step 2).
- Stable angina (prophylaxis), including vasospastic angina.
💊 Dose
| Indication | Dose |
|---|
| Hypertension | 5 mg once daily, increased if needed to max 10 mg once daily |
| Angina | 5 mg once daily, increased if needed to max 10 mg once daily |
| Hepatic impairment | Start at the low end; titrate slowly |
🔄 Interactions
- Simvastatin: maximum 20 mg daily with amlodipine (↑ myopathy risk) - consider atorvastatin instead.
- CYP3A4 inhibitors (clarithromycin, itraconazole, ritonavir, diltiazem): ↑ amlodipine levels → hypotension, oedema.
- CYP3A4 inducers (rifampicin, carbamazepine, St John's wort): ↓ effect.
- Ciclosporin and tacrolimus: amlodipine may raise their levels - monitor.
- Additive hypotension with other antihypertensives, alpha-blockers and PDE-5 inhibitors.
⚠️ Cautions
- Hepatic impairment (half-life prolonged).
- Acute phase after MI and heart failure (use only if clearly indicated).
- Elderly: start low because of postural hypotension and falls.
🚫 Contraindications
- Cardiogenic shock.
- Significant aortic stenosis.
- Unstable angina.
💥 Side Effects
- Very common/common: ankle oedema, flushing, headache, dizziness, palpitations, fatigue, abdominal pain, nausea.
- Uncommon: gingival hyperplasia, mood change, visual disturbance, muscle cramps, rash, urinary frequency.
- Rare: hepatitis, jaundice, pancreatitis, gynaecomastia.
☠️ Overdose
- Profound vasodilation and hypotension; reflex tachycardia is common, although bradycardia can occur in severe cases. Non-cardiogenic pulmonary oedema can occur.
- Manage with TOXBASE: fluids, IV calcium, vasopressors, high-dose insulin euglycaemia therapy in severe cases.
📚 References
