Each uncoated extended release tablet contains: Felodipine 5 mg, Excipients Q.S.
Pharmacology: Felodipine is a dihydropyridine Class a calcium antagonist which lowers the arterial blood pressure by decreasing vascular resistance. In-vitro selectivity for smooth muscle in the arterioles is exhibited by Felodipine. In therapeutic doses, Felodipine has no direct effect on cardiac contractility. Felodipine does not affect venous smooth muscle or adrenergic vasomotor control.
It has been shown by electro-physiological studies that Felodipine has no direct effect on conduction in the specialized conducting system of the heart and has no effect on the AV nodal refractoriness.
Felodipine produces an increase in heart rate which is counteracted when concurrent beta receptor blockers are administered.
Pharmacokinetics: Felodipine is almost completely absorbed from the gastrointestinal tract after oral doses but undergoes extensive first-pass metabolism, with a bioavailability of about 15% (range 10 to 25%). It is extensively metabolized in the gut and the liver and is excreted almost entirely as metabolites, about 70% of a dose being excreted in urine and the remainder in feces. The terminal elimination half-life is reported to be about 11 to 16 hours after oral administration of an immediate-release preparation, but longer with a modified release formulation. Felodipine is about 99% bound to plasma proteins.
It is used in the management of hypertension and angina pectoris.
Felodipine is given by mouth, generally in a modified release formulation for administration once daily in the morning. In hypertension the usual initial dose is 5 mg daily by mouth, adjusted as required; the usual maintenance dose is 2.5 to 10 mg daily and doses above 20 mg daily are not usually needed. In angina the usual initial dose is 5 mg daily are not usually needed. In angina the usual initial dose is 5 mg daily increased if necessary to 10 mg daily. Lower doses may be required in the elderly and in patients with impaired liver function.
Excessive peripheral vasodilation with marked hypotension, which may be accompanied by bradycardia, may be caused by over dosage. Severe hypotension should be treated symptomatically with the patient placed supine and legs elevated. Bradycardia, if present, should be treated with atropine 0.5 mg to 1 mg intravenously. If this is not sufficient, plasma volume should be increased by infusion with e.g. glucose, normal saline or dextran solutions. Sympathomimetic drugs with a predominant effect on the alpha 1-adrenoreceptor may be given, e.g. metaraminol or phenylephrine.
Felodipine extended release tablet should not be used in women of child-bearing potential, or in persons hypersensitive to Felodipine, patients with cardiogenic shock. It is not known whether Felodipine is excreted in breast milk or whether it has harmful effects on the new-born.
Felodipine extended release tablets may precipitate significant hypotension with tachycardia. In susceptible individuals this may result in myocardial ischemia.
It should be contraindicated in pregnancy and lactation.
Dizziness, fatigue, flushing, headache, hypotension and peripheral edema may occur. Gastrointestinal disturbances, as well as eye pain, increased micturition frequency, lethargy, and mental depression have also been reported. At the start of treatment a paradoxical increase in ischemic chest pain may occur. In a few patients an excessive fall in blood pressure has led to cerebral or myocardial ischemia or transient blindness. There have been reports of abnormalities in liver function, fever and rashes due to hypersensitivity reactions. Gingival hyperplasia has been reported but is often reversible on drug withdrawal. Sexual dysfunction/impotence occurs rarely.
The elimination of Felodipine is increased by powerful enzyme including agents such as some anticonvulsants (e.g. phenytoin, carbamazepine and phenobarbitone). In patients taking such medicines higher than normal doses of Felodipine extended release tablets may be required. Conversely, the elimination of Felodipine is impaired by enzyme inhibitors such as cimetidine, erythromycin and certain flavonoids present in grapefruit juice. When such medicines are given concomitantly the dosage of felodipine tablets may need to be reduced. No dosage adjustment is required when Felodipine extended release tablet are given concomitantly with digoxin. Felodipine does not appear to affect the unbound fraction of other extensively bound medicines, such as warfarin, due to its high degree of plasma protein binding.
Store at temperatures not exceeding 30°C.
C08CA02 - felodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.
ER tab 5 mg (uncoated) x 100's.