From the Guidelines
Nifedipine should not be administered to patients with non-ST-elevation acute coronary syndromes (NSTE-ACS) in the absence of beta-blocker therapy due to the increased risk of harm. This recommendation is based on the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes, which states that immediate-release nifedipine should not be administered to patients with NSTE-ACS in the absence of beta-blocker therapy, with a Level of Evidence: B 1.
Key Points to Consider
- Nifedipine is a calcium channel blocker that works by relaxing and widening blood vessels, allowing blood to flow more easily through them, which reduces blood pressure and improves oxygen supply to 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 and feet.
Important Considerations for Use
- Nifedipine should be taken consistently, either always with food or always without food.
- Grapefruit juice should be avoided as it can increase nifedipine blood levels.
- Patients should not crush or chew extended-release formulations as this can lead to dangerous rapid drug release.
- The use of nifedipine in patients with NSTE-ACS should be approached with caution, and alternative treatments should be considered, as suggested by 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 1.
From the FDA Drug Label
CLINICAL PHARMACOLOGY 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 Nifedipine is a peripheral arterial vasodilator which acts directly on vascular smooth muscle The binding of nifedipine to voltage-dependent and possibly receptor-operated channels in vascular smooth muscle results in an inhibition of calcium influx through these channels.
Nifedipine Mechanism of Action: Nifedipine reduces arterial blood pressure through peripheral arterial vasodilatation and a reduction in peripheral vascular resistance by inhibiting calcium ion influx into vascular smooth muscle and cardiac muscle.
- Key Points:
- Inhibits calcium ion influx into vascular smooth muscle and cardiac muscle
- Acts as a peripheral arterial vasodilator
- Reduces peripheral vascular resistance
- Lowers arterial blood pressure 2
From the Research
Nifedipine Overview
- Nifedipine is a dihydropyridine calcium channel antagonist with predominantly vasodilatory activity 3.
- It is used in the treatment of hypertension and angina pectoris, and is available in modified-release formulations that are effective and generally well tolerated 3, 4.
Efficacy and Safety
- Modified-release nifedipine has been shown to have beneficial effects on markers of vascular function and can reduce the need for coronary procedures in patients with coronary artery disease 3.
- The extended-release formulation of nifedipine has been demonstrated to be effective in reducing blood pressure values and conferring cardiovascular protection in high-risk patients 4.
- However, nifedipine can cause peripheral edema, particularly of the lower limbs, and has been ranked as one of the highest inducing peripheral edema among dihydropyridine calcium channel blockers 5.
Clinical Use
- Nifedipine can be used as a first-line treatment for essential hypertension in general practice, but may have a higher incidence of side effects compared to other treatments 6.
- In patients with coronary heart disease, nifedipine is contraindicated in case of recent myocardial infarction or unstable angina, and should be used with caution in patients with stable angina 7.
- The combination of nifedipine with renin-angiotensin system blockers may reduce the risk of peripheral edema associated with nifedipine treatment 5.