Felop Mechanism of Action

Pharmacology: Felodipine is a dihydropyridine calcium-channel blocker with actions similar to those of nifedipine. It is used in the treatment of hypertension and angina pectoris. Felodipine is a highly vascular selective calcium antagonist which lowers arterial blood pressure by decreasing systemic vascular resistance. Due to high degree of selectivity for smooth muscle in the arterioles, felodipine in therapeutic doses has no direct effect on cardiac contractility or conduction. Because there is no effect on venous smooth muscle or adrenergic vasomotor control, felodipine is not associated with orthostatic hypotension. Felodipine is effective in all grades of hypertension. It can be used as monotherapy or in combination with other antihypertensive drugs eg, β-adrenoceptor blockers, diuretics or ACE inhibitors, in order to achieve an increased antihypertensive effect. Felodipine reduces both systolic and diastolic blood pressure and can be used in isolated systolic hypertension. Felodipine maintains its antihypertensive effect during concomitant therapy with nonsteroidal anti-inflammatory drugs. Felodipine has anti-anginal and anti-ischaemic effects due to improved myocardial oxygen supply/demand balance. Felodipine improves exercise tolerance and reduces anginal attacks in patients with stable effort-induced angina pectoris. Felodipine is effective and well tolerated in adult patients irrespective of age and race and is also well tolerated in the presence of concomitant disease such as congestive heart failure, asthma and other obstructive pulmonary disease, impaired renal function, diabetes, gout, hyperlipidaemia, Raynaud's disease and in renal transplant recipients. Felodipine has no effect on blood glucose levels or lipid profile.
Pharmacokinetics: Felodipine is administered as extended-release tablets from which it is completely absorbed in the gastrointestinal tract. The extended-release film-coated tablets produce a prolonged absorption phase of felodipine. This results in even felodipine plasma concentrations within the therapeutic range for 24 hours. Plasma concentrations are directly proportional to dose within the therapeutic dose range 2.5-10 mg. It is extensively metabolized in the liver and is excreted almost entirely as metabolites about 70% of a dose being excreted in urine and the remainder in faeces. There is no significant accumulation during long-term treatment.