Adult: As extended-release tab/cap: 10-40 mg bid or 30-90 mg once daily, depending on the preparation (refer to detailed product guideline). Dosage must be adjusted according to patient response. Elderly: Dose reduction may be necessary.
Adult: As extended-release tab/cap: 10-40 mg bid or 20-90 mg once daily, depending on the preparation (refer to detailed product guideline). Dosage must be adjusted according to patient response. Elderly: Dose reduction may be necessary.
Oral Angina pectoris
Adult: Prophylaxis of chronic stable cases: Monotherapy or in combination with β-blockers: As extended-release tab/cap: 10-40 mg bid or 30-90 mg once daily, depending on the preparation (refer to detailed product guideline). Dosage must be adjusted according to patient response. Elderly: Dose reduction may be necessary.
Oral Raynaud's syndrome
Adult: As immediate-release softgel cap: Initially, 5 mg tid, may be adjusted according to patient response up to Max 20 mg tid. Elderly: Dose reduction may be necessary.
Dose reduction may be necessary.
immediate-release: May be taken with or without food. Avoid grapefruit juice. extended-release: Should be taken on an empty stomach. Swallow whole, do not crush/split/chew. Avoid grapefruit juice.
Cardiogenic shock, clinically significant aortic stenosis, unstable angina, during or within 1 month of MI, acute attacks of angina; secondary prevention of MI. Concomitant use with rifampicin.
Patient with hypotension, poor cardiac reserve, heart failure, hypertrophic cardiomyopathy with outflow tract obstruction, diabetes mellitus; undergoing major surgery. Extended-release form: Patient with oesophageal obstruction, Kock pouch (ileostomy after proctocolectomy), inflammatory bowel disease, gastrointestinal strictures (e.g. severe gastrointestinal narrowing, obstruction, bowel resection, gastric bypass, colon cancer, vertical banded gastroplasty). Immediate-release preparations are not recommended to manage angina or hypertension. Avoid abrupt withdrawal. Hepatic impairment. Elderly. Pregnancy and lactation.
Significant: Peripheral oedema, reflex tachycardia, increased angina or MI, cardiac ischaemic pain, symptomatic hypotension with or without syncope; impaired glucose tolerance. Rarely, bezoar formation (use of extended-release formulation in patients with gastrointestinal strictures). Gastrointestinal disorders: Constipation, abdominal pain, dyspepsia, flatulence, dry mouth, nausea. General disorders and administration site conditions: Feeling unwell, oedema, fatigue. Musculoskeletal and connective tissue disorders: Muscle cramps. Nervous system disorders: Headache, dizziness, tremors. Psychiatric disorders: Nervousness, mood changes. Respiratory, thoracic and mediastinal disorders: Nasal congestion, cough, wheezing, sore throat, dyspnoea. Vascular disorders: Vasodilatation, flushing.
PO: C, Z (Use for tocolysis is associated with pulmonary oedema and cardiovascular complications (hypotension, cardiogenic shock, myocardial infarction, atrial fibrilation).)
Patient Counseling Information
This drug may cause dizziness, lethargy, and transient blindness due to severe hypotension; if affected, do not drive or operate machinery.
Monitor blood pressure, heart rate, LFTs; signs and symptoms of heart failure and peripheral oedema.
Symptoms: Hypotension, tachycardia, bradycardia, hyperglycaemia, metabolic acidosis, hypoxia, cardiogenic shock with pulmonary oedema, and disturbances of consciousness leading to coma. Management: Symptomatic and supportive treatment. Activated charcoal may be given if the ingestion of a potentially toxic amount is within 1 hour. Alternatively, gastric lavage may be considered in adults if potentially life-threatening overdose occurs within 1 hour. Treat hypotension as a result of cardiogenic shock and arterial vasodilatation with Ca (10-20 mL of a 10% Ca gluconate solution administered IV over 5-10 minutes). May continue treatment with ECG monitoring if the effects are inadequate. May administer vasoconstricting sympathomimetics (e.g. dopamine, norepinephrine) if an insufficient increase in blood pressure is achieved with Ca. Symptomatic bradycardia may be treated with atropine.
May cause additive hypotensive effects with IV Mg sulfate and other antihypertensive agents (e.g. β-blockers, ACE inhibitors, diuretics). Increased exposure and plasma concentration with erythromycin, ritonavir, ketoconazole, fluoxetine, nefazodone, quinupristin/dalfopristin, cisapride, valproic acid, cimetidine, diltiazem. May increase plasma levels of digoxin and tacrolimus. Decreased exposure with phenytoin, carbamazepine, phenobarbital. May reduce plasma concentrations of quinidine. Potentially Fatal: Decreased bioavailability and efficacy with rifampicin.
Avoid concomitant use with grapefruit or grapefruit juice as it increases plasma levels of nifedipine. May reduce serum levels with St. John’s wort. May elevate serum concentrations with alcohol. Food may decrease the rate but not the extent of absorption.
May cause false-negative aldosterone/renin ratio (ARR) and falsely increase the spectrophotometric values of urinary vanillylmandelic acid. May lead to false-positive result when performing barium contrast x-ray.
Description: Nifedipine, is a dihydropyridine Ca-channel blocker that prevents Ca ions from entering the slow channels or select voltage-sensitive areas of the vascular smooth muscle and myocardium during depolarisation, producing coronary vascular smooth muscle relaxation and coronary vasodilation. It also reduces peripheral and coronary vascular resistance, resulting in increased coronary blood flow, cardiac output and stroke volume while lowering afterload. Onset: Immediate-release: Approx 20 minutes. Pharmacokinetics: Absorption: Rapidly and almost completely absorbed from the gastrointestinal tract. May decrease the rate but not the extent of absorption with food. Bioavailability: 40-77% (immediate-release); 65-89% (extended-release). Time to peak plasma concentration: 30-60 minutes (immediate-release). Distribution: Crosses the placenta and enters breast milk. Plasma protein binding: Approx 92-98%. Metabolism: Extensively oxidised in the liver by CYP3A4 isoenzyme into inactive metabolites. Undergoes extensive hepatic first-pass metabolism. Excretion: Via urine (60-80% as inactive metabolites); faeces. Elimination half-life: Approx 2-5 hours.
Store below 30°C. Protect from light and moisture.