From the Guidelines
No, amlodipine and nifedipine are not the same medication, although they belong to the same class of drugs called calcium channel blockers (specifically dihydropyridine calcium channel blockers). Both medications work by relaxing blood vessels to improve blood flow and lower blood pressure, but they have different chemical structures, dosing schedules, and duration of action. Amlodipine (brand names include Norvasc) is typically taken once daily and has a longer half-life of about 30-50 hours, providing consistent 24-hour blood pressure control 1. Nifedipine (brand names include Adalat, Procardia) is available in immediate-release forms that may require multiple daily doses or extended-release formulations for once-daily dosing, with a shorter half-life of 2-5 hours.
Some key differences between the two medications include:
- Different dosing schedules: Amlodipine is usually taken once daily, while nifedipine may require multiple daily doses or extended-release formulations 1.
- Different side effect profiles: Amlodipine is associated with headache and edema, while nifedipine is associated with hypotension, dizziness, flushing, nausea, constipation, and edema 1.
- Different drug interactions: Amlodipine and nifedipine may have different interactions with other medications, so they are not interchangeable without medical supervision.
These medications may have slightly different side effect profiles and drug interactions, so they are not interchangeable without medical supervision. Patients should never substitute one for the other without consulting their healthcare provider. The most recent and highest quality study, published in 2013, supports the use of amlodipine and nifedipine for symptom control in patients with unstable angina/non-ST-elevation myocardial infarction, but highlights the importance of careful selection and monitoring of patients receiving these medications 2.
From the FDA Drug Label
Amlodipine is a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle. 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.
Amlodipine and nifedipine are not the same, although they are both calcium channel blockers. They have similar mechanisms of action, but they are different drugs with distinct properties and effects. [3] [4]
From the Research
Comparison of Amlodipine and Nifedipine
- Amlodipine and nifedipine are both calcium channel blockers used to treat hypertension and angina, but they have different pharmacokinetic properties 5, 6, 7, 8, 9.
- Studies have compared the efficacy and safety of amlodipine and nifedipine in patients with chronic ischemic heart disease, mild-to-moderate essential hypertension, and stable exertional angina pectoris 5, 6, 7, 8, 9.
- The results of these studies suggest that amlodipine and nifedipine have comparable antianginal and antihypertensive efficacy, but amlodipine may have a better tolerability profile and a more convenient once-daily dosing regimen 5, 6, 7, 8, 9.
Efficacy and Safety
- Amlodipine has been shown to be as effective as nifedipine in reducing the signs of ischemia and improving exercise tolerance in patients with chronic ischemic heart disease 5.
- In patients with mild-to-moderate essential hypertension, amlodipine and nifedipine have been found to have comparable efficacy in lowering blood pressure 6, 7.
- Amlodipine has also been shown to have a better antianginal efficacy than nifedipine in patients with stable exertional angina pectoris, with a significant reduction in weekly anginal attacks and consumption of glyceryl trinitrate tablets 8.
- The incidence of adverse events has been found to be lower with amlodipine compared to nifedipine in some studies 5, 9.
Pharmacokinetic Properties
- Amlodipine has a long half-life, which allows for once-daily dosing, whereas nifedipine has a shorter half-life and is often dosed twice daily 5, 6, 7, 8, 9.
- The pharmacokinetic properties of amlodipine may contribute to its better tolerability profile and more convenient dosing regimen compared to nifedipine 5, 6, 7, 8, 9.