Nifedipine information from DrugsUpdate
P - Caution when used during pregnancy
FI - Food *
LI - Lab *
Nifedipine (brand name Adalat, Nifedical, and Procardia) is a dihydropyridine calcium channel blocker. Its main uses are as an antianginal (especially in Prinzmetal's angina) and antihypertensive, although a large number of other uses have recently been found for this agent, such as Raynaud's phenomenon, premature labor, and painful spasms of the esophagus in cancer and tetanus patients. It is also commonly used for the small subset of pulmonary hypertension patients whose symptoms respond to calcium channel blockers.
Pharmacodynamics
Pharmacokinetics
Nifedipine blocks the slow calcium channels thus preventing the flow of calcium ions into the cell. It produces peripheral and coronary vasodilatation, reduces afterload, peripheral resistance and BP, increases coronary blood flow and causes reflex tachycardia. It has little or no effect on cardiac conduction and rarely has negative inotropic activity.
Absorption
Rapidly and completely absorbed from the GI tract (oral); peak plasma concentrations after 30 min (as liquid-filled capsules).
Distribution
Enters breast milk. Protein-binding: 92-98%.
Metabolism
Extensive hepatic first-pass metabolism.
Excretion
Via urine (70-80% as inactive metabolites); 2 hours(elimination half-life).
Nifedipine Indications / Nifedipine Uses
Information Not Available
Nifedipine Adverse Reactions / Nifedipine Side Effects
Peripheral oedema, hypotension, palpitations, tachycardia, flushing, dizziness, headache, nausea, increased micturition frequency, lethargy, eye pain, mental depression, visual disturbances, gingival hyperplasia, myalgia, tremor, impotence, fever, paradoxical increase in ischaemic chest pain during initiation of treatment, rashes, abnormalities in liver function (including cholestasis), GI obstruction in some tablets covered in indigestable membrane.
Precautions
Monitor
Frequently assess patient for response to treatment. Ensure that therapy is periodically reviewed to determine if it needs to be continued without change or if a dose change (eg, increase, decrease, discontinuation) is indicated. Frequently monitor BP during initial administration and following any dose escalation.
Overdosage
Hypotension and bradycardia; hyperglycaemia, metabolic acidosis, coma. Management is mainly supportive and symptomatic.
Special Precautions
Hypotension, poor cardiac reserve, heart failure (deterioration has been noted), severe aortic stenosis, hepatic impairment, DM, porphyric patients, pregnancy. Avoid abrupt withdrawal (associated with exacerbation of angina). Discontinue if with ischaemic pain following administration.
Other Drug Interactions
Potentiates antihypertensives. Increases the effects of neuromuscular-blocking agents and CYP1A2 substrates (e.g. theophylline, aminophylline). Enhances toxic effects of magnesium. Enhanced antihypertensive effects with alpha 1-blockers, aldesleukin, and antipsychotics. Reduced effects with calcium. With concurrent use with quinidine, serum concentration is increased while reduced in quinidine. Decreased levels/effects with CYP3A4 inducers (e.g. carbamazepine, nafcillin, phenobarbital, phenytoin, and rifampicin). Increased levels/effects with CYP3A4 inhibitors (e.g. azole antifungals, cimetidine, erythromycin, and HIV-protease inhibitors).
Other Interactions
Food Interaction
Serum levels may be decreased with food, St John's wort. Increased levels/effects with grapefruit juice, ethanol, garlic. Avoid ephedra, yohimbe, ginseng (may worsen hypertension).
Dosage
Oral
Hypertension
Adult: Long-acting preparation: 10-40 mg bid, or 20-90 mg once daily.
Child: 1 month–12 years: 200–300 mcg/kg tid (max: 3 mg/kg daily or 90 mg daily); 12–18 years: 5–20 mg tid (max: 90 mg daily). Dose frequency may vary based on the preparation used. For hypertensive crisis: 1 month-18 years: 250-500 mcg/kg as a single dose.
Elderly: Dose reduction may be necessary.
Hepatic impairment: Reduce dose by 50%-60% in patients with cirrhosis.
Oral
Angina pectoris
Adult: Long-acting preparation: 10-40 mg bid or 30-90 mg once daily. Liquid-filled capsules: 5-20 mg tid.
Child: Angina in Kawasaki disease or progeria: 1 month–18 years: 200–300 mcg/kg tid (max: 3 mg/kg/day or 90 mg/day). Dose frequency may vary based on the preparation used.
Elderly: Dose reduction may be necessary.
Hepatic impairment: Reduce dose by 50%-60% in patients with cirrhosis.
Oral
Raynaud's syndrome
Adult: Liquid-filled capsules: 5-20 mg tid.
Child: 2–18 years: 2.5-10 mg 2–4 times daily; intiate with low doses at night. Increase slowly to prevent postural hypotension. Dose frequency may vary based on the preparation used.
Elderly: Dose reduction may be necessary.
Hepatic impairment: Reduce dose by 50%-60% in patients with cirrhosis
Food(before/after)
Retard, GITS & OROS: May be taken with or without food. (Avoid grapefruit juice. Swallow whole, do not chew/crush.)
Immediate-release: May be taken with or without food. (Avoid grapefruit juice.)
List of Contraindications
Nifedipine and Pregnancy
Caution when used during pregnancy
Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.
Nifedipine and Lactation
Information Not Available
Nifedipine and Children
Safety and efficacy not established
Nifedipine and Geriatic
May experience greater hypotensive effects
Nifedipine and Other Contraindications
Acute MI, cardiogenic shock, acute unstable angina, treatment of anginal attack in chronic stable angina.
Storage
Information Not Available
Lab interference
Information Not Available
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