Nifedipin T20 Retard

Each tablet contains Active ingredient - Nifedipine 20 mg.
Excipients/Inactive Ingredients: Maize starch, Lactose monohydrate, Microcrystalline cellulose, Hypromellose, Polysorbate 80, magnesium stearate, Talc, Titanium dioxide, Macrogol 6000, Red ferric dioxide.

Pharmacology: Pharmacodynamics: Nifedipine is a calcium antagonist of the 1,4-dihydropyridine type. Calcium antagonists reduce the transmembranal influx of calcium ions through the slow calcium channel into the cell. As a specific and potent calcium antagonist, nifedipine acts particularly on the cells of the myocardium and the smooth muscle cells of the coronary arteries and the peripheral resistance vessels. The main action of nifedipine is to relax arterial smooth muscle, both in the coronary and peripheral circulation.
In hypertension, the main action of nifedipine is to cause peripheral vasodilatation and thus reduce peripheral resistance.
In angina, nifedipine reduces peripheral and coronary vascular resistance, leading to an increase in coronary blood flow, cardiac output and stroke volume, whilst decreasing after-load. Additionally, nifedipine dilates submaximally both clear and atherosclerotic coronary arteries, thus protecting the heart against coronary artery spasm and improving perfusion to the ischaemic myocardium.
Pharmacokinetics: Nifedipine is rapidly and almost completely absorbed from the gastrointestinal tract, but undergoes extensive hepatic first-pass metabolism. Nifedipine is about 92% to 98% bound to plasma proteins. It is distributed into breast milk. It is extensively oxidised in the liver and 80% to 95% of a dose is excreted in the urine, and the remainder in the faeces, almost entirely as inactive metabolites. The terminal half-life following longer-acting formulations administration does not represent a meaningful parameter as a plateau-like plasma concentration is maintained during release from the tablets and absorption.

Treatment of mild to moderate hypertension.
Prophylaxis of chronic stable angina pectoris either as monotherapy or in combination with a beta-blocker.

Recommended Dose: In mild to moderate hypertension, the recommended initial dose is one 20 mg tablet once daily. If necessary, the dosage can be increased according to individual requirements up to a maximum of 90 mg once daily.
For the prophylaxis of angina pectoris, the recommended initial dose is one 30 mg tablet once daily. The dosage can be increased according to individual requirements up to a maximum of 90 mg once daily.
Mode of Administration: Nifedipine is administered orally. The tablets should be swallowed whole with a glass of water either with or without food. The tablets should be taken at approximately 24-hour intervals, i.e. at the same time each day, preferably during the morning.

Symptoms: Disturbances of consciousness to the point of coma, a drop in blood pressure, tachycardia, bradycardia, hyperglycemia, metabolic acidosis, hypoxia, cardiogenic shock with pulmonary oedema.
Treatment: As far as treatment is concerned, elimination of nifedipine and the restoration of stable cardiovascular conditions have priority. Elimination must be as complete as possible, including the small intestine, to prevent the otherwise inevitable subsequent absorption of the active substance.

Patients with known hypersensitivity to nifedipine, or to any of the excipients.
Cases of cardiogenic shock, clinically significant aortic stenosis, unstable angina, or myocardial infarction.
Patients with a history of gastro-intestinal obstruction, oesophageal obstruction.
Patients with a Kock pouch.
Patients with inflammatory bowel disease or Crohn's disease.
Administrated concomitantly with rifampicin since effective plasma levels of nifedipine may not be achieved owing to enzyme induction.

Caution should be exercised in patients with hypotension as there is a risk of further reduction in blood pressure.
In patients with impaired liver function careful monitoring and, in severe cases, a dose reduction may be necessary.
Caution in patients whose cardiac reserve is poor. Deterioration of heart failure has occasionally been observed with nifedipine.
Diabetic patients taking nifedipine may require adjustment of their control.
In dialysis patients with malignant hypertension and hypovolaemia, a marked decrease in blood pressure can occur.
Effects on ability to drive and operate machine: Reactions to the drug, which vary in intensity from individual to individual, may impair the ability to drive or to operate machinery. This applies particularly at the start of treatment, on changing the medication and in combination with alcohol.

Pregnancy: In animal studies, nifedipine has been shown to produce embryotoxicity, foetotoxicity and teratogenicity. There are no adequate well controlled studies in pregnant women. Nifedipine should not be used during pregnancy unless the clinical condition of the woman requires treatment with nifedipine.
Lactation: The drug is not recommended for use during breastfeeding because nifedipine has been reported to be excreted in human milk and the effects of nifedipine exposure to the infant are not known.

The most common adverse effects of nifedipine are associated with its vasodilator action and often diminish on continued therapy. They include dizziness, flushing, headache, hypotension, peripheral oedema, tachycardia, and palpitations. Nausea and other gastrointestinal disturbances, increased micturition frequency, lethargy, eye pain, visual disturbances, and mental depression have also occurred.
There have been reports of rashes (including erythema multiforme), fever, and abnormalities in liver function, including cholestasis, due to hypersensitivity reactions.
Gingival hyperplasia, myalgia, tremor, and impotence have been reported.

Nifedipine may increase the blood pressure lowering effect of concomitant applied antihypertensives.
When nifedipine is administered simultaneously with β-receptor blockers the patient should be carefully monitored, since deterioration of heart failure is also known to develop in isolated cases.
Co-administration of inducers of the cytochrome P450 3A4 system (cimetidine, diltiazem, fluoxetine), the clinical response to nifedipine should be monitored and, if necessary, an increase in the nifedipine dose considered.
The simultaneous administration of nifedipine and digoxin may lead to reduced digoxin clearance and, hence, an increase in the plasma digoxin level.
Co-administration of nifedipine with quinidine may lower plasma quinidine levels, and after discontinuation of nifedipine, a distinct increase in plasma quinidine levels may be observed in individual cases. Consequently, when nifedipine is either additionally administered or discontinued, monitoring of the quinidine plasma concentration, and if necessary, adjustment of the quinidine dose are recommended.
Administration of nifedipine together with grapefruit juice thus results in elevated plasma concentrations and prolonged action of nifedipine due to a decreased first pass metabolism or reduced clearance. As a consequence, the blood pressure lowering effect of nifedipine may be increased.

Store in a well-closed container, in a dry place, protect from light. Do not store above 30°C.

Calcium Antagonists

C08CA05 - nifedipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.

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