<p>Nifedipine is an inhibitor of Calcium Channel Blocker that blocks the transmembrane influx of Calcium ions into muscle cells. Nifedipine has selective effects as a dilator of arterial vessels. Nifedipine dilates main coronary and systemic arteries. As a result blood pressure falls and this elicits a sympathetic reflex response causing tachycardia and an increased cardiac output. Pulmonary arterial pressure also falls. Nifedipine has direct negative inotropic effects on cardiac muscles and these effects are seen at higher doses than dose which causes arterial vasodilatation.</p>