From the Guidelines
Nifedipine, a calcium channel blocker, should not be administered to patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) in the absence of beta-blocker therapy due to its potential to cause harm, as evidenced by a dose-related increase in mortality in patients with coronary artery disease (CAD) 1.
Effects of Nifedipine
The effects of nifedipine include:
- Peripheral vasodilation, which can lead to decreased blood pressure and improved blood flow to the heart
- Little direct effect on contractility, atrioventricular conduction, and heart rate
- Coronary vasodilation, making it preferred in vasospastic angina
- Alleviation of ischemia due to obstructive CAD by decreasing heart rate and blood pressure
Important Considerations
- Immediate-release nifedipine should be avoided in patients with NSTE-ACS due to its potential to cause harm 1
- Long-acting preparations may be useful in older patients with systolic hypertension
- Patients taking nifedipine should avoid grapefruit juice, as it can increase the medication's concentration in the bloodstream, potentially leading to enhanced side effects
Side Effects
Common side effects of nifedipine include:
- Headache
- Dizziness
- Flushing
- Swelling in the ankles or feet
- Gum overgrowth with long-term use
Dosage and Administration
Nifedipine comes in immediate-release forms (typically 10-30 mg three times daily) and extended-release formulations (30-90 mg once daily) 1.
Monitoring and Precautions
Blood pressure should be monitored regularly while taking nifedipine, and patients should be aware of the potential risks and benefits of the medication, particularly in the context of CAD and NSTE-ACS 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. Nifedipine decreases peripheral vascular resistance, careful monitoring of blood pressure during the initial administration and titration of nifedipine extended-release tablets are suggested. Mild to moderate peripheral edema occurs in a dose-dependent manner with nifedipine extended-release tablets.
The effects of Nifedipine (Calcium Channel Blocker) include:
- Vasodilation: Nifedipine causes arterial vasodilation, leading to decreased peripheral vascular resistance and reduced arterial blood pressure.
- Peripheral edema: Nifedipine can cause mild to moderate peripheral edema in a dose-dependent manner.
- Hypotension: Nifedipine can lead to hypotension, especially when used in combination with other medications that lower blood pressure.
- Effects on laboratory tests: Nifedipine may cause rare, usually transient, but occasionally significant elevations of enzymes such as alkaline phosphatase, CPK, LDH, SGOT, and SGPT.
- Platelet aggregation: Nifedipine decreases platelet aggregation in vitro, which may increase the risk of bleeding. 2 2
From the Research
Effects of Nifedipine on Cardiovascular Disease
- Nifedipine, a calcium channel blocking agent, 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.
- In Prinzmetal's variant angina, nifedipine relieves the acute spasm of a large coronary artery, and thereby reverses the sudden decrease in myocardial oxygen supply 3.
- In chronic stable angina, the efficacy of nifedipine stems from an interplay of direct and reflex effects, including a decrease in systemic vascular resistance and myocardial oxygen demand 3.
Effects of Nifedipine on Hypertension
- Modified-release formulations of nifedipine are effective antihypertensive therapies and are generally well tolerated 4.
- Nifedipine gastrointestinal therapeutic system (GITS) and nifedipine retard have beneficial effects on the overall incidence of major cardiovascular events in patients with hypertension 4, 5.
- 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.
Effects of Nifedipine on Angina Pectoris
- Nifedipine and atenolol are first choice drugs in the treatment of angina pectoris, and their combination has proved extremely efficacious in patients who were not adequately controlled by either drug in monotherapy 6.
- The association of nifedipine and atenolol does not induce notable depressive effects on myocardial contractility, except in patients with severely compromised basal resting contractile function 6.
- Nifedipine GITS reduces the need for coronary procedures in patients with coronary artery disease 4.