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Dihydropyridine Calcium Channel Blocker Pregnancy: Limited post-marketing data are not sufficient to inform a drug-associated risk; use in pregnancy only recommended when there is no safer alternative and the disease carries greater risk to mother and foetus.

Amlodipine

Brand names: Istin

Amlodipine is a long-acting dihydropyridine calcium-channel blocker used for hypertension and chronic stable angina.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 5 mg once daily (usual initial antihypertensive dose)
Route: Oral
Frequency: Once daily
Max: 10 mg once daily
Hypertension: initial 5 mg once daily, max 10 mg once daily; adjust to blood pressure goals, generally waiting 7 to 14 days between titration steps. Small, fragile, or elderly patients, or patients with hepatic insufficiency may be started on 2.5 mg once daily. Chronic stable or vasospastic angina: 5 to 10 mg (lower dose in elderly and hepatic insufficiency); most patients require 10 mg. Coronary artery disease: 5 to 10 mg once daily. NOTE: the UK eMC source is a fixed-dose amlodipine/valsartan combination SPC and does not give a standalone amlodipine-monotherapy mg dose; monotherapy figures above are taken from the US FDA label (openFDA). Clinician to confirm against a UK amlodipine monotherapy SPC.

Dose adjustments

Renal

No dosage adjustment required for mild to moderate renal impairment (per combination SPC); no clinical data in severe renal impairment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

•Adult recommended starting dose: 5 mg once daily with maximum dose 10 mg once daily. ( 2.1 ) о Small, fragile, or elderly patients, or patients with hepatic insufficiency may be started on 2.5 mg once daily. ( 2.1 ) •Pediatric starting dose: 2.5 mg to 5 mg once daily. ( 2.2 ) Important Limitation : Doses in excess of 5 mg daily have not been studied in pediatric patients. ( 2.2 ) 2.1 Adults The usual initial antihypertensive oral dose of amlodipine besylate tablet is 5 mg once daily and the maximum dose is 10 mg once daily. Small, fragile, or elderly patients, or patients with hepatic insufficiency may be started on 2.5 mg once daily and this dose may be used when adding amlodipine …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2026-04-20. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

  • Known sensitivity to amlodipine (US FDA label)
  • Hypersensitivity to dihydropyridine derivatives (per combination SPC §4.3)
  • Severe hypotension (per combination SPC §4.3)
  • Shock including cardiogenic shock (per combination SPC §4.3)
  • Obstruction of the outflow tract of the left ventricle (e.g. high grade aortic stenosis) (per combination SPC §4.3)
  • Haemodynamically unstable heart failure after acute myocardial infarction (per combination SPC §4.3)

Side effects

  • Oedema (most common; dose related)
  • Fatigue
  • Nausea
  • Abdominal pain
  • Somnolence

Interactions

  • CYP3A inhibitors (moderate and strong): increased amlodipine exposure; may require dose reduction; monitor for hypotension and oedema
  • CYP3A inducers: monitor blood pressure closely
  • Simvastatin: limit simvastatin dose to 20 mg daily when co-administered
  • Sildenafil: monitor for hypotension
  • Immunosuppressants (cyclosporine, tacrolimus): amlodipine may increase their exposure; monitor trough levels

Clinical monograph

How it works

It blocks L-type calcium channels in vascular smooth muscle, causing peripheral arterial vasodilatation and reduced afterload; its long half-life gives smooth 24-hour control.

Prescribing in practice

  • Dose-dependent ankle oedema is the commonest reason for stopping and does not respond to diuretics.
  • It is a first-line antihypertensive option, particularly useful in older patients.
  • Unlike non-dihydropyridine calcium-channel blockers, it is generally acceptable in stable heart failure when needed for blood pressure or angina.

Monitoring

Monitor blood pressure for response and review for peripheral oedema.

Counselling the patient

  • Ankle swelling can occur; it is harmless but report it if troublesome.
  • Flushing or headache may occur early and usually settles.
  • Take it at the same time each day.

Evidence & guidelines

Calcium-channel blockers are a first-line antihypertensive (especially age ≥55, or people of Black African/African-Caribbean family origin) per NICE NG136.

Reference: NICE NG136 Hypertension in Adults; ALLHAT Trial (JAMA 2002); ASCOT-BPLA (Lancet 2005); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

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