Amlodipine

Oral
Prinzmetal's angina
Adult: Initially, 5 mg once daily, may be increased to 10 mg once daily according to clinical response.
Elderly: Initiate at lower doses and titrate according to clinical response.
Hepatic impairment: Initiate at lower doses and titrate according to clinical response.

Oral
Chronic stable angina
Adult: Initially, 5 mg once daily, may be increased to 10 mg once daily according to clinical response.
Elderly: Initiate at lower doses and titrate according to clinical response.
Hepatic impairment: Initiate at lower doses and titrate according to clinical response.

Oral
Hypertension
Adult: Initially, 5 mg once daily, may be increased to 10 mg once daily according to clinical response.
Child: 6-17 years Initially, 2.5 mg once daily, may be increased to 5 mg once daily after 4 weeks according to clinical response.
Elderly: Initiate at lower doses and titrate according to clinical response.
Hepatic impairment: 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. Patient Counselling This drug may cause dizziness, headache, fatigue or nausea; if affected, do not drive or operate machinery. Monitoring Parameters Monitor blood pressure and heart rate.

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.

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).

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.
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 30-50 hours.

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

Anti-Anginal Drugs / 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.