What is the effect of nifedipine (calcium channel blocker)?

From the Guidelines

Nifedipine should be used with caution, as it can cause hypotension, dizziness, flushing, nausea, constipation, and edema, and its use without concomitant beta-blocker therapy may increase the risk of adverse events, including mortality, in patients with coronary artery disease 1.

Key Points

• Nifedipine is a calcium channel blocker that works by relaxing and widening blood vessels, allowing blood to flow more easily and reducing the workload on the heart.
• The typical starting dose for hypertension is 30-60 mg once daily of the extended-release formulation, with a maximum daily dose of 90-120 mg.
• For angina, the usual dose is 30-60 mg of extended-release nifedipine once daily.
• Immediate-release nifedipine is rarely used now due to concerns about rapid blood pressure drops.
• Common side effects include headache, flushing, dizziness, and swelling in the ankles or feet.
• Nifedipine should be taken consistently, either always with food or always without food, and grapefruit juice should be avoided as it can increase nifedipine levels in the blood.

Clinical Considerations

• Nifedipine should not be used without concomitant beta-blocker therapy in patients with coronary artery disease, as it may increase the risk of adverse events, including mortality 1.
• Calcium channel blockers, including nifedipine, should be avoided in patients with significantly impaired left ventricular function or atrioventricular conduction.
• The use of nifedipine in patients with variant angina may be beneficial, but it should be used with caution and under close monitoring.

Evidence Summary

• The 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes recommends that immediate-release nifedipine should not be administered to patients with NSTE-ACS in the absence of beta-blocker therapy 1.
• The 2012 ACCF/AHA focused update incorporated into the ACCF/AHA 2007 guidelines for the management of patients with unstable angina/non-ST-elevation myocardial infarction recommends that rapid-release, short-acting dihydropyridines, such as nifedipine, must be avoided in the absence of concomitant beta blockade because of increased adverse potential 1.
• The European Society of Cardiology task force recommends that calcium channel blockers, including nifedipine, should be avoided in patients with significantly impaired left ventricular function or atrioventricular conduction, and that nifedipine should not be used without concomitant beta-blocker therapy in patients with coronary artery disease 1.

From the FDA Drug Label

Nifedipine is a calcium ion influx inhibitor (slow-channel blocker or calcium ion antagonist) which inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. The mechanism by which nifedipine reduces arterial blood pressure involves peripheral arterial vasodilatation and, consequently, a reduction in peripheral vascular resistance The reduction in calcium influx by nifedipine causes arterial vasodilation and decreased peripheral vascular resistance which results in reduced arterial blood pressure.

The effect of nifedipine (calcium channel blocker) is to reduce arterial blood pressure by causing peripheral arterial vasodilatation and reducing peripheral vascular resistance. This is achieved by inhibiting the influx of calcium ions into vascular smooth muscle and cardiac muscle, resulting in arterial vasodilation and decreased peripheral vascular resistance 2.

• Key effects:
  • Reduces arterial blood pressure
  • Causes peripheral arterial vasodilatation
  • Reduces peripheral vascular resistance
• Mechanism of action:
  • Inhibits calcium ion influx into vascular smooth muscle and cardiac muscle
  • Results in arterial vasodilation and decreased peripheral vascular resistance

From the Research

Effects of Nifedipine on Cardiovascular Disease

• Nifedipine, a calcium channel blocker, has been shown to be safe and effective in the treatment of various cardiac disorders, including Prinzmetal's variant angina and chronic stable angina 3.
• The efficacy of nifedipine in chronic stable angina stems from an interplay of direct and reflex effects, including a decrease in systemic vascular resistance and myocardial oxygen demand 3.
• Nifedipine may also be of value in the therapy of unstable angina, acute myocardial infarction, and hypertension, as well as in the protection of the myocardium at risk during open heart surgery 3.

Effects of Nifedipine on Hypertension

• Modified-release formulations of nifedipine are effective antihypertensive therapies and are generally well tolerated 4.
• The extended-release formulation of nifedipine given once daily provides a relatively constant concentration profile and has proved to be effective in reducing blood pressure values 5.
• Nifedipine confers cardiovascular protection as effectively as diuretics in high-risk patients, with a smaller incidence of adverse metabolic consequences 5.

Clinical Trials and Outcomes

• The ACTION trial demonstrated that nifedipine GITS significantly reduced the combined incidence of all-cause mortality, myocardial infarction, refractory angina, heart failure, stroke, and peripheral revascularization by 13% in hypertensives 6.
• Nifedipine GITS also significantly reduced the incidence of any stroke or transient ischemic attack by almost 30% in both normotensives and hypertensives, and the need for coronary angiography by 21% in normotensives and 16% in hypertensives 6.
• The use of nifedipine in combination with other agents, such as diltiazem, may be effective in controlling severe hypertension 7.