Amlodipine is a blood pressure medication that treats three main conditions: high blood pressure (hypertension), chronic stable angina, and vasospastic angina. It belongs to a class of drugs called calcium channel blockers, and it’s one of the most widely prescribed medications in the world. Most people take it once daily as a tablet, and it works by relaxing blood vessels so blood flows more easily.
High Blood Pressure
The most common reason people are prescribed amlodipine is to lower blood pressure. It’s approved as a first-line treatment for hypertension in adults, and it can be used alone or alongside other blood pressure medications. The standard starting dose for adults is 5 mg once a day, with a maximum of 10 mg. Older adults or those with liver problems typically start at 2.5 mg.
In one of the largest blood pressure trials ever conducted, known as ALLHAT, amlodipine performed comparably to other major blood pressure drug classes in preventing heart attacks and reducing death. Across more than 33,000 participants followed for six years, rates of coronary heart disease and overall mortality were nearly identical between amlodipine and the other medications studied. This is part of why amlodipine remains a go-to choice for managing hypertension decades after it first became available.
Dose adjustments happen gradually. Your prescriber will typically wait 7 to 14 days between increases to see how your blood pressure responds before raising the dose.
Chronic Stable Angina
Amlodipine is also prescribed for chronic stable angina, the type of chest pain that happens predictably during physical exertion or stress. By relaxing the arteries that supply the heart, it reduces the heart’s workload and improves blood flow to the heart muscle. This means you can exercise or exert yourself more before chest pain starts. Amlodipine can be used on its own for angina or combined with other chest pain medications.
Vasospastic Angina
A less common but important use is treating vasospastic angina, sometimes called Prinzmetal’s angina. This type of chest pain is caused by sudden spasms in the coronary arteries rather than by physical exertion. It often strikes at rest, frequently during the night or early morning. In a randomized placebo-controlled trial, amlodipine significantly reduced the frequency of anginal episodes compared to placebo, and patients also needed fewer nitroglycerin tablets for breakthrough pain. The benefit held up during long-term follow-up as well.
Reducing Cardiovascular Risk in CAD
For patients who have been diagnosed with coronary artery disease through imaging but don’t have heart failure, amlodipine has an additional role: reducing the risk of hospitalization for angina and lowering the chance of needing procedures like stents or bypass surgery. This protective benefit applies even beyond its effects on blood pressure and chest pain symptoms.
How Amlodipine Works
Your blood vessels contain smooth muscle cells that contract and relax to control blood flow. For these muscles to contract, calcium needs to enter the cells through specific channels. Amlodipine blocks those channels, preventing calcium from getting in. With less calcium inside the cells, the muscle relaxes, the blood vessels widen, and blood pressure drops. The same mechanism explains why it helps angina: wider coronary arteries mean more oxygen-rich blood reaching the heart.
Beyond this direct relaxation effect, amlodipine also appears to improve how the inner lining of blood vessels functions in people with high blood pressure. This is relevant because damage to that lining is an early step in the development of cardiovascular disease.
What to Expect When Taking It
Amlodipine is a slow-acting, long-lasting medication. After you take a dose, it reaches its highest concentration in your blood somewhere between 6 and 12 hours later. Its effects then taper gradually, with a half-life of about 30 to 50 hours. That long half-life is why once-daily dosing works and why it takes several days of consistent use before the drug reaches its full effect in your body. It also means that if you miss a single dose, your blood pressure won’t spike immediately, though you should still take it as consistently as possible.
Common Side Effects
The most well-known side effect is swelling in the ankles and feet, called peripheral edema. This happens because amlodipine dilates arteries more than veins, which allows fluid to pool in the lower legs. The swelling is dose-dependent: roughly 5% of people experience it at the 5 mg dose, but that jumps to about 25% at 10 mg. While uncomfortable and sometimes cosmetically bothersome, it isn’t dangerous. Other common side effects include fatigue, flushing, and dizziness, particularly when you first start the medication or after a dose increase.
Use in Children
Amlodipine is one of the few blood pressure medications with dosing guidelines for children. The American Academy of Pediatrics includes it as a recommended option for treating hypertension in kids. Children ages 1 to 6 typically start at 0.1 mg per kilogram of body weight per day, while older children may begin at 2.5 mg daily, with a maximum of 10 mg. Dosing is weight-based and adjusted as the child grows.
Drug Interactions to Know About
Amlodipine has a notable interaction with simvastatin, a common cholesterol-lowering medication. When taken together, amlodipine increases simvastatin levels in the blood, raising the risk of muscle damage. The FDA has set a firm ceiling: if you take amlodipine, your simvastatin dose should not exceed 20 mg per day. If you need more aggressive cholesterol lowering, your prescriber will likely switch you to a different statin that doesn’t have this interaction.