Amlodipine

Oral
Hypertension

Oral
Chronic stable angina, Prinzmetal's angina

Initiate at lower doses and titrate according to clinical response.

May be taken with or without food.

Severe hypotension, shock (including cardiogenic shock), left ventricular outflow tract obstruction (e.g. high-grade aortic stenosis), haemodynamically unstable heart failure after acute MI.

Patient with CHF. Hepatic impairment. Children and elderly. Pregnancy and lactation.

Significant: Symptomatic hypotension, peripheral oedema.
Cardiac disorders: Palpitations.
Eye disorders: Visual disturbance.
Gastrointestinal disorders: Abdominal pain, nausea, dyspepsia, diarrhoea, constipation.
General disorders and administration site conditions: Oedema, fatigue, asthenia.
Musculoskeletal and connective tissue disorders: Ankle swelling, muscle cramps.
Nervous system disorders: Somnolence, dizziness, headache.
Respiratory, thoracic and mediastinal disorders: Dyspnoea.
Vascular disorders: Flushing.

PO: C

This drug may cause dizziness, headache, fatigue or nausea, if affected, do not drive or operate machinery.

Monitor blood pressure and heart rate.

Symptoms: Excessive peripheral vasodilation, reflex tachycardia, hypotension, shock. Management: Initiate active cardiac and respiratory monitoring if massive overdose occurs. Frequent blood pressure measurements are essential. For clinically significant hypotension, provide CV support including elevation of the extremities and judicious administration of fluids. If hypotension remains unresponsive, consider administration of vasopressors (e.g. phenylephrine) with attention to circulating volume and urine output. IV Ca gluconate may help reverse the effects of Ca channel blockade. In healthy volunteers, the use of activated charcoal immediately after or up to 2 hours after ingestion has been shown to significantly reduce the absorption rate. Gastric lavage may be beneficial in some cases.

Increased exposure with strong or moderate CYP3A4 inhibitors (e.g. protease inhibitors, azole antifungals, macrolides, verapamil, diltiazem). Decreased plasma concentration with CYP3A4 inducers (e.g. rifampicin). Risk of hyperkalemia with dantrolene. Additive blood pressure-lowering effects with other antihypertensives. May increase the exposure of simvastatin, ciclosporin, and mTOR inhibitors (e.g. sirolimus, tacrolimus, temsirolimus, everolimus).

Increased bioavailability with grapefruit or grapefruit juice. Decreased plasma concentration with St John's wort.

May cause a false-negative aldosterone/renin ratio (ARR).

Description:
Mechanism of Action: Amlodipine, a dihydropyridine Ca-channel blocker, reduces peripheral vascular resistance and blood pressure by relaxing the coronary vascular smooth muscle and coronary vasodilation through inhibition of Ca ion transmembrane influx into cardiac and vascular smooth muscles.
Onset: Antihypertensive effect: 24-48 hours.
Duration: Antihypertensive effect: ≥24 hours.
Pharmacokinetics:
Absorption: Well absorbed. Bioavailability: Approx 64-90%. Time to peak plasma concentration: 6-12 hours.
Distribution: Enters breast milk. Volume of distribution: Approx 21 L/kg. Plasma protein binding: Approx 97.5%.
Metabolism: Extensively metabolised in the liver to inactive metabolites.
Excretion: Via urine (60% as metabolites, 10% as unchanged drug). Terminal elimination half-life: Approx 35-50 hours.

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 2162, Amlodipine. https://pubchem.ncbi.nlm.nih.gov/compound/Amlodipine. Accessed Oct. 26, 2023.

Store between 15-30°C. Protect from light.

Calcium Antagonists

C08CA01 - amlodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.

Amlodipine 1 mg/mL Oral Solution (Brillpharma Limited). MHRA. https://products.mhra.gov.uk. Accessed 31/03/2023.

Amlodipine 1 mg/mL Oral Suspension (Rosemont Pharmaceuticals Ltd). MHRA. https://products.mhra.gov.uk. Accessed 31/03/2023.

Amlodipine 10 mg Tablets (Torrent Pharma UK Ltd.). MHRA. https://products.mhra.gov.uk. Accessed 10/02/2023.

Amlodipine Besylate Tablet (ACI Healthcare USA, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 10/02/2023.

Anon. Amlodipine. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 10/02/2023.

Anon. Amlodipine. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 10/02/2023.

Buckingham R (ed). Amlodipine. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 10/02/2023.

Istin 10 mg Hard Capsules (Upjohn UK Limited). MHRA. https://products.mhra.gov.uk. Accessed 10/02/2023.

Joint Formulary Committee. Amlodipine. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 10/02/2023.

Katerzia Suspension (Azurity Pharmaceuticals, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 31/03/2023.

Norliqva Solution (CMP Pharma, Inc.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 31/03/2023.

Norvasc Tablet (Pfizer Laboratories Div Pfizer Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 10/02/2023.

Norvasc Tablet (Pfizer Pharmaceuticals LLC). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my. Accessed 10/02/2023.

Rex Medical Limited. Vasorex Tablet data sheet 04 August 2020. Medsafe. http://www.medsafe.govt.nz. Accessed 10/02/2023.