Nifedipine Pharmacology


About Nifedipine
A dihydropyridine calcium channel blocker, Antianginal, antihypertensive,tocolytic.
Mechanism of Action of Nifedipine
Nifedipine is a dihydropyridine Ca channel blocker. It exerts it`s antianginal, antihypertensive actions through blocking the influx of Ca2+ ions through voltage gated L-type Ca channels to the peripheral vascular smooth muscle cells, Coronary smooth muscle cells and to the myocardial cells. Thus causes dilatation of vascular endothelium, decrease peripheral resistance, & reduce myocardial oxygen demand .It markedly relax arterioles and milder effects on veins, decrease after load and increase cardiac index. It do not compromise haemodynamics and cerebral and renal perfusion. It inhibits platelet aggregation and relaxes bronchial, uterine, and ureteric smooth muscles. It is an effective uterine relaxant agent.
Migraine: It is used in migraine by reducing intracellular Ca+2 overload due to brain hypoxia and other causes.
Pharmacokinets of Nifedipine
Absorption: Well absorbed orally, Distribution: Widely distributed in a protein bound form, Metabolism: Metabolized in liver. Excretion: Excreted through urine and faeces
Onset of Action for Nifedipine
Half to two hours
2 to 3minutes for sublingual
Duration of Action for Nifedipine
4 to 8hours,
2 to 3minutes for sublingual
Half Life of Nifedipine
2 to 5 hours
Side Effects of Nifedipine
9.Orthostatic hypotension
10.Leg cramps
12.Gingival hyperplasia
13.Congestive heart failures

Contra-indications of Nifedipine
1.Acute myocardial infarction
2.Heart failure
3.Aortic stenosis
5.Cardiogenic shock
6.Hypersensitivity to the drug
7.Unstable angina
8.Coronary artery diseases
Special Precautions while taking Nifedipine
1.Congestive heart failure
2.Cardiovascular insufficiency
4.Left ventricular outflow obstruction
5.Hepatic impairment
6.Slowly withdraw the drug with caution
7.Use cautiously along with other antihypertensive drugs
8.Diabetes mellitus

Pregnancy Related Information
Old Age Related Information
Use with caution.
Breast Feeding Related Information
Use with caution.
Children Related Information
Use with caution.
Indications for Nifedipine
2.Hypertensive emergencies
3.Prinzmetal`s angina and Stable angina
4.As Tocolytic agent
5.In mountain sickness
6.Bronchial asthma
7.Peripheral vascular disorders
8. Migraine prophylaxis
9.Oesophageal spasm

Interactions for Nifedipine
Histamine H2 antagonists: Cimetidine and ranitidine enhance the bioavailability of nifedipine.
Beta-blockers: Though advantageous in some, concomitant use results in increased adverse effects like bradycardia and conduction disturbances.
Digitalis Glycosides: Increased serum digoxin levels with pssible toxicity.
Magnesium Sulphate: With parenteral magnesium suplhate neuromuscular blockade and hypotension may occur.
Theophyllines: Increased pharmacological effects of theophylline, resulting in toxicity.
Quinidine: Hypotension, bradycardia, ventricular tachycardia, AV block and pulmonary oedema may occur. Serum quinidine levels may also be decreased by nifedipine.
Anticoagulants: Increased prothrombin time.
Fentanyl: Severe hypotension or increased fluid requirements.
Typical Dosage for Nifedipine
Prinzmetal`s angina and Stable angina: Starts with 10mg 8th hourly. Increases the dosage up to 20mg 8th hourly. Further increases the dosage based on patient`s response at weekly intervals and repeat at 8th to 6th hourly.
Maximum daily dose: 120mg
Hypertension: 20mg twice daily or 30 to 60mg once daily extended release formulations. Adjust the dosage based on patient`s response.Maximum dose: 4omg twice daily
Maximum dose for extended release formulations: 120mg/day
Emergency reduction of blood pressure: Chew 10mg tablet and at the same time swallow another 10mg tablet. Repeat at every 20 to 30minutes.
As Tocolytic: 10mg sublingually and repeat at 20minutes for 2 to 3 doses.
Maintenance dosage: 10 to 20mg orally every 4 to 6 hours
For hypertensive emergencies: 250mcg to 500mcg/kg/dose 3 to 4 times daily.

Schedule of Nifedipine
Storage Requirements for Nifedipine
Store at room temperature below 30 degree C. Protect from moisture and avoid freezing.
Effects of Missed Dosage of Nifedipine
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Nifedipine
Monitor & support cardiac and respiratory functions. Measure the BP. Give cardiovascular support by elevating the limbs and maintaining fluid balance. Administer vasopressers like Nor epinephrine and Calcium gluconate if required.

Home Delivery for Nifedipine in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including nifedipine.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for nifedipine and other medicines and health products. Home delivery services for nifedipine may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take nifedipine only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for nifedipine before they complete the sale. You can get this information while placing the order for nifedipine with the pharmacy.

Nifedipine is a generic medicine name and there are several brands available for it. Some of the brands for nifedipine might be better known than nifedipine itself. If the pharmacy that's willing to deliver medicines to your home doesn't have nifedipine in stock, you can ask for one of the branded alternatives for nifedipine.