Nifedipine

Nifedipine, a dihydropyridine derivative, belongs to the group of ^Ca2+channelblockers, pharmaceuticals that selectively block the voltage-dependent influx of calcium through the L-type (L=long lasting) calcium channel but do not affect other calcium channels. Calcium antagonists lower peripheral vascular resistance.

In the human organism, the L-type calcium channel is found in smooth muscle (e.g., in vascular walls), in the cardiovascular system, and also in neurons. In smooth muscle and cardiac muscle, the "long-lasting calcium channels", which allow slow calcium influx into the cell upon depolarization of the cell membrane, are essential for electromechanical coupling. Dihydropyridine-type calcium antagonists are vasoselective. They lower peripheral resistance. This can lead to reflex tachycardia and pectanginal discomfort. Dihydropyridine-type calcium antagonists may be combined with beta-blockers, preventing reflex tachycardia.

Nifedipine is mainly used to treat hypertensive emergency, vasospastic angina (Prinzmetal angina, Variant angina), Raynaud's syndrome and angina pectoris (stress angina). As an L-type calcium channel antagonist, the drug has vasodilating and blood pressure-lowering effects.

Nifedipine is metabolized by CYP3A4. In cases of co-administration with a more potent CYP3A4 inhibitor, plasma levels of nifedipine may increase.

Glucocorticoids (methylprednisolone): Inhibition of methylprednisolone metabolism (CYP3A4) and inhibition of P-glycoprotein.

Lithium: risk of increased lithium toxicity.

Nitrate derivatives: increased antihypertensive effect and feeling of weakness

Amiodarone and digoxin: increased risk of bradycardia

Beta-receptor blockers, antiarrhythmics or cardiac glycosides: increased effect possible

The following frequency data shall be used for the evaluation of adverse reactions:

• Very frequent: more than 1 treated person out of 10
• Often: 1 to 10 treated from 100
• Occasionally: 1 to 10 treated from 1.000
• Rare: 1 to 10 treated from 10.000
• Very rare: less than 1 treated person per 10.000