Amlodipine
Calcium Channel Blocker for High Blood Pressure and Angina
Quick Facts About Amlodipine
Key Takeaways About Amlodipine
- Proven cardiovascular protection: Amlodipine effectively lowers blood pressure and reduces the risk of heart attack, stroke, and cardiovascular death
- Once-daily convenience: Its long half-life (30–50 hours) allows once-daily dosing at any time of day, with or without food
- Common side effect – ankle swelling: Peripheral oedema occurs in more than 10% of patients and is dose-dependent
- Avoid grapefruit juice: Grapefruit can unpredictably increase amlodipine blood levels, leading to excessive blood pressure reduction
- Do not stop abruptly: Always consult your doctor before stopping amlodipine, as sudden discontinuation may cause a rebound increase in blood pressure
What Is Amlodipine and What Is It Used For?
Amlodipine is a calcium channel blocker (CCB) that relaxes and widens blood vessels, making it easier for blood to flow through them. It is primarily prescribed to treat high blood pressure (hypertension) and chest pain caused by angina pectoris, including Prinzmetal's (variant) angina.
Amlodipine belongs to a group of medicines known as dihydropyridine calcium channel blockers. It works by blocking voltage-dependent L-type calcium channels in vascular smooth muscle and cardiac muscle cells. By preventing calcium from entering these cells, amlodipine causes the blood vessels to relax and dilate, which reduces peripheral vascular resistance and lowers blood pressure.
In patients with high blood pressure (hypertension), amlodipine reduces the resistance in blood vessels, allowing blood to pass through more easily. This reduction in pressure decreases the workload on the heart and helps protect against long-term complications of hypertension, including heart attack, stroke, kidney disease, and heart failure. The European Society of Cardiology (ESC) and the American Heart Association (AHA) both recommend calcium channel blockers as first-line treatment for hypertension.
In patients with angina pectoris, amlodipine works by increasing blood flow to the heart muscle, which then receives more oxygen. This mechanism helps prevent the chest pain that occurs when the heart muscle does not receive enough blood. Amlodipine is particularly effective for Prinzmetal's angina (variant angina), a rare form of angina caused by coronary artery spasm, because it directly relaxes the coronary arteries.
It is important to understand that amlodipine does not provide immediate relief of chest pain during an angina attack. It is a preventive medication that reduces the frequency and severity of angina episodes over time. For acute angina attacks, short-acting nitrates (such as sublingual nitroglycerin) should be used instead.
Amlodipine is one of the most commonly prescribed medications worldwide. It was first approved for medical use in 1990 and is included on the World Health Organization's List of Essential Medicines, reflecting its importance in global healthcare. It is available as both a branded product and in numerous generic formulations, making it widely accessible and affordable.
What Should You Know Before Taking Amlodipine?
Before starting amlodipine, inform your doctor about all your medical conditions, especially heart failure, liver disease, and any other medications you are taking. Amlodipine is contraindicated in severe hypotension, haemodynamically significant aortic stenosis, and cardiogenic shock.
Contraindications
You should not take amlodipine if any of the following apply to you:
- Allergy to amlodipine or any other calcium channel blocker – symptoms may include itching, skin redness, or difficulty breathing
- Very low blood pressure (severe hypotension) – amlodipine could lower your blood pressure to dangerous levels
- Severe aortic stenosis (narrowing of the aortic valve) with haemodynamic instability – the blood vessel-relaxing effects can worsen symptoms
- Cardiogenic shock – a condition where the heart cannot pump enough blood to meet the body's needs
- Unstable heart failure following a heart attack – unless medically supervised and carefully monitored
Warnings and Precautions
Talk to your doctor or pharmacist before taking amlodipine if you have or have had any of the following conditions:
- Recent heart attack (myocardial infarction) – extra monitoring may be needed
- Heart failure – calcium channel blockers should be used with caution in heart failure patients
- Hypertensive crisis (very high blood pressure) – a different treatment approach may be needed initially
- Liver disease – amlodipine is extensively metabolised by the liver, and impaired liver function can lead to higher drug levels in the blood, potentially requiring dose adjustment
- Elderly patients – your doctor may start with a lower dose and increase it gradually
Use in Children and Adolescents
Amlodipine has not been studied in children under 6 years of age. In children and adolescents aged 6 to 17 years, amlodipine may be used to treat hypertension, but only under specialist medical supervision. The starting dose in this age group is typically 2.5 mg once daily, with a maximum dose of 5 mg daily. Your child's doctor will determine the appropriate dose based on weight, age, and blood pressure response.
Pregnancy and Breastfeeding
The safety of amlodipine during pregnancy has not been established in humans. Animal studies have suggested potential harm to the developing foetus at high doses. If you are pregnant, think you might be pregnant, or are planning to become pregnant, you must inform your doctor before taking amlodipine. Your doctor may recommend an alternative blood pressure medication with a better-established safety profile during pregnancy, such as labetalol, methyldopa, or nifedipine (extended-release).
Amlodipine passes into breast milk in small amounts. If you are breastfeeding or about to start breastfeeding, tell your doctor before taking amlodipine. Your doctor will weigh the benefits of the medication against any potential risks to your baby and advise you accordingly.
Driving and Operating Machinery
Amlodipine can occasionally cause dizziness, drowsiness, headache, or fatigue, particularly at the start of treatment or after a dose increase. If you experience any of these symptoms, you should not drive or operate machinery until the symptoms have resolved. Consult your doctor immediately if these effects persist or worsen.
Food and Drink Interactions
You should avoid grapefruit and grapefruit juice while taking amlodipine. Grapefruit inhibits the CYP3A4 enzyme responsible for metabolising amlodipine, which can lead to increased drug levels in the blood. This may cause an unpredictable increase in the blood pressure-lowering effect, potentially resulting in dizziness, excessive flushing, or oedema. Amlodipine can be taken with or without food, at any time of day, but should be taken at the same time each day for consistent effect.
How Does Amlodipine Interact with Other Drugs?
Amlodipine can interact with several medications, including other blood pressure drugs, antifungals, HIV protease inhibitors, certain antibiotics, and immunosuppressants. Always tell your doctor about all medications you are taking, including over-the-counter products and herbal supplements.
Amlodipine is primarily metabolised by the liver enzyme CYP3A4. Drugs that inhibit this enzyme can increase amlodipine blood levels, while drugs that induce it can decrease them. Additionally, amlodipine can increase blood levels of certain other drugs, including simvastatin and cyclosporine. The following tables summarise the most clinically important interactions.
Major Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Simvastatin | Cholesterol-lowering (statin) | Amlodipine increases simvastatin blood levels, raising risk of muscle damage (rhabdomyolysis) | Limit simvastatin to 20 mg/day when combined with amlodipine |
| Cyclosporine | Immunosuppressant | Amlodipine may increase cyclosporine levels | Monitor cyclosporine levels closely; dose adjustment may be needed |
| Dantrolene (IV infusion) | Muscle relaxant | Risk of severe hyperkalaemia and cardiovascular collapse | Avoid combination if possible; use with extreme caution |
| Verapamil / Diltiazem | Calcium channel blockers | Additive negative effects on heart rate, conduction, and blood pressure | Use combination only under specialist supervision |
Moderate Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Ketoconazole / Itraconazole | Antifungal | CYP3A4 inhibitors that increase amlodipine blood levels | Monitor blood pressure closely; dose reduction may be needed |
| Ritonavir / Indinavir / Nelfinavir | HIV protease inhibitors | Strong CYP3A4 inhibitors that significantly increase amlodipine levels | Use with caution; monitor for excessive blood pressure lowering |
| Rifampicin | Antibiotic (TB treatment) | Strong CYP3A4 inducer that decreases amlodipine effectiveness | Monitor blood pressure; higher amlodipine dose may be needed |
| Erythromycin / Clarithromycin | Macrolide antibiotics | CYP3A4 inhibitors that increase amlodipine levels | Monitor blood pressure during concurrent use |
| Tacrolimus / Sirolimus / Everolimus | Immunosuppressants | Amlodipine may alter immunosuppressant blood levels | Monitor immunosuppressant levels; adjust doses as needed |
| St. John's Wort (Hypericum perforatum) | Herbal supplement | CYP3A4 inducer that may reduce amlodipine effectiveness | Avoid concurrent use or monitor blood pressure closely |
If you are already taking other medications for high blood pressure, be aware that amlodipine can further lower your blood pressure. Your doctor will adjust your doses accordingly. However, amlodipine is frequently and safely combined with ACE inhibitors (e.g. ramipril, lisinopril), angiotensin receptor blockers (ARBs, e.g. valsartan, losartan), and thiazide diuretics as part of an optimised blood pressure treatment regimen.
What Is the Correct Dosage of Amlodipine?
The recommended starting dose for adults is 5 mg once daily. Your doctor may increase the dose to 10 mg once daily depending on your response. Take the tablet at the same time each day with a glass of water, with or without food.
Always take amlodipine exactly as your doctor has told you. Do not change your dose without consulting your doctor first. Amlodipine tablets should be swallowed whole with a glass of water and can be taken at any time of day, but it is best to take them at the same time each day for a consistent effect.
Adults
Hypertension (High Blood Pressure)
Starting dose: 5 mg once daily
Maximum dose: 10 mg once daily
Your doctor may start with 5 mg and increase to 10 mg after 2–4 weeks if blood pressure is not adequately controlled. The full blood pressure-lowering effect is typically achieved within 7–14 days of continuous use.
Angina Pectoris (Chest Pain)
Usual dose: 5–10 mg once daily
The dose is adjusted based on symptom control and tolerance. Amlodipine reduces the frequency of angina episodes but does not provide immediate relief during an attack.
Children and Adolescents (6–17 years)
Hypertension Only
Starting dose: 2.5 mg once daily
Maximum dose: 5 mg once daily
Note: A 2.5 mg tablet is not widely available. Some 5 mg tablets are not scored and cannot be reliably split in half. Consult your pharmacist about appropriate formulations for paediatric dosing.
Elderly Patients
Elderly patients may be started on the standard 5 mg dose, though the doctor may consider a more gradual dose increase. Amlodipine clearance is slightly reduced in elderly patients, which may result in higher blood levels. However, no specific dose adjustment is routinely required for age alone. Blood pressure should be monitored regularly.
Patients with Liver Impairment
Amlodipine is extensively metabolised by the liver. In patients with hepatic impairment, the half-life is prolonged and blood levels are higher. Your doctor may prescribe a lower starting dose (2.5 mg) and titrate carefully based on response and tolerability.
Missed Dose
If you forget to take a dose, simply skip it and take your next dose at the usual time. Do not take a double dose to make up for the missed one. If you miss doses frequently, consider setting a daily reminder or taking your tablet alongside a routine activity (such as brushing your teeth in the morning).
Overdose
Taking too many amlodipine tablets can cause dangerously low blood pressure, which may lead to dizziness, fainting, or shock. In severe cases, overdose can result in pulmonary oedema (fluid in the lungs), which may develop 24–48 hours after ingestion. The skin may feel cold and clammy, and loss of consciousness can occur. Seek immediate medical attention if you suspect an overdose. Contact your local emergency services or poison control centre without delay.
Stopping Amlodipine
Do not stop taking amlodipine without consulting your doctor. Your doctor will tell you how long you need to take this medication. Stopping amlodipine abruptly can cause a rebound increase in blood pressure, which may increase the risk of cardiovascular events. If your doctor decides to discontinue amlodipine, they may gradually reduce the dose or switch you to an alternative medication.
What Are the Side Effects of Amlodipine?
The most common side effect of amlodipine is peripheral oedema (ankle and foot swelling), which affects more than 1 in 10 people. Other common side effects include headache, dizziness, flushing, and fatigue. Most side effects are mild and often improve over time.
Like all medicines, amlodipine can cause side effects, although not everybody gets them. Most side effects are dose-dependent, meaning they are more likely at higher doses. If any side effects become severe or persistent, consult your doctor.
- Sudden wheezing, chest pain, shortness of breath, or difficulty breathing
- Swelling of the eyelids, face, lips, tongue, or throat (signs of angioedema)
- Severe skin reactions with extensive rash, blisters, or skin peeling (Stevens-Johnson syndrome or toxic epidermal necrolysis)
- Irregular or abnormal heart rhythm
- Severe abdominal and back pain (possible pancreatitis)
Very Common
May affect more than 1 in 10 people
- Oedema (swelling due to fluid retention, especially in the ankles and feet)
Common
May affect up to 1 in 10 people
- Headache
- Dizziness
- Drowsiness (especially at the start of treatment)
- Palpitations (awareness of heartbeat)
- Flushing (hot flushes)
- Abdominal pain and nausea
- Altered bowel habits, diarrhoea, or constipation
- Fatigue and weakness
- Visual disturbances and double vision
- Muscle cramps
- Swollen ankles
Uncommon
May affect up to 1 in 100 people
- Mood changes, anxiety, depression, insomnia
- Tremor, taste disturbance, fainting
- Numbness or tingling in the extremities
- Tinnitus (ringing in the ears)
- Low blood pressure
- Rhinitis (nasal congestion, sneezing)
- Cough
- Dry mouth, vomiting
- Hair loss, increased sweating, itchy or discoloured skin
- Urination problems, increased urination at night
- Erectile dysfunction, gynaecomastia
- Joint or muscle pain, back pain
- Weight gain or weight loss
Rare and Very Rare
May affect up to 1 in 1,000 people or fewer
- Confusion
- Decreased white blood cells or platelets
- Elevated blood sugar (hyperglycaemia)
- Peripheral neuropathy
- Gum swelling (gingival hyperplasia)
- Abnormal liver function, hepatitis, jaundice
- Increased muscle tone (hypertonia)
- Vasculitis (inflammation of blood vessels)
- Photosensitivity (skin sensitivity to light)
- Extrapyramidal symptoms (rigidity, tremor, movement disorders)
If you experience any side effects not listed here, or if any side effect becomes severe, contact your doctor or pharmacist. Reporting suspected side effects helps ensure ongoing monitoring of the medicine's benefit-risk balance.
How Should You Store Amlodipine?
Store amlodipine tablets at room temperature, away from light and moisture, out of the reach and sight of children. Do not use after the expiry date printed on the packaging.
No special storage conditions are required for amlodipine tablets. Store the medicine in its original packaging to protect it from moisture and light. Keep the blister packs or bottle tightly closed. Check the expiry date (marked "EXP" on the carton and blister) before taking any tablets. The expiry date refers to the last day of the stated month.
Do not flush unused tablets down the toilet or throw them in household waste. Return any unused or expired medication to your pharmacy for safe disposal, which protects the environment from pharmaceutical contamination.
What Does Amlodipine Contain?
Each amlodipine tablet contains the active ingredient amlodipine (as besylate salt) and several inactive ingredients necessary for tablet manufacture. The 5 mg tablets are small, round, and white to off-white. The 10 mg tablets are similar but slightly larger.
Active Ingredient
The active substance is amlodipine. Each 5 mg tablet contains 5 mg amlodipine (as amlodipine besylate, also known as amlodipine besilate). Each 10 mg tablet contains 10 mg amlodipine (as amlodipine besylate).
Inactive Ingredients (Excipients)
The other ingredients are: microcrystalline cellulose, sodium starch glycolate, magnesium stearate, disodium hydrogen citrate, crospovidone, and croscarmellose sodium. These are standard pharmaceutical excipients used to ensure proper tablet formation, disintegration, and absorption.
Sodium Content
This medicine contains less than 1 mmol (23 mg) sodium per tablet, meaning it is essentially "sodium-free". This is relevant for patients on a sodium-restricted diet.
Tablet Appearance and Packaging
5 mg tablets: White to off-white, approximately 6.6 mm round, biconvex tablets.
10 mg tablets: White to off-white, approximately 8.5 mm round, biconvex tablets.
Available in blister packs of 10, 14, 20, 28, 30, 50, 60, 90, 98, and 100 tablets. Not all pack sizes may be marketed in your country.
How Does Amlodipine Work in the Body?
Amlodipine works by blocking L-type calcium channels in vascular smooth muscle, causing blood vessels to relax and dilate. This reduces peripheral vascular resistance and lowers blood pressure. Its long half-life of 30–50 hours provides stable 24-hour blood pressure control with once-daily dosing.
Calcium plays a central role in the contraction of muscle cells, including the smooth muscle cells that line blood vessel walls. When calcium enters these cells through voltage-dependent L-type calcium channels, it triggers a cascade of events that leads to muscle contraction and narrowing of the blood vessel. Amlodipine selectively blocks these channels, preventing calcium from entering the cells and thereby preventing contraction.
The result is vasodilation (widening of the blood vessels), which reduces the resistance that the heart has to pump against. This is known as reducing peripheral vascular resistance or afterload. By decreasing afterload, the heart does not have to work as hard to pump blood, which lowers blood pressure and reduces myocardial oxygen demand.
Amlodipine is classified as a dihydropyridine calcium channel blocker, which means it predominantly affects vascular smooth muscle rather than cardiac muscle. This is in contrast to non-dihydropyridine CCBs (such as verapamil and diltiazem), which have significant effects on heart rate and cardiac conduction. As a result, amlodipine does not typically slow the heart rate and is generally well tolerated in combination with beta-blockers.
Pharmacokinetic Profile
After oral administration, amlodipine is slowly and well absorbed from the gastrointestinal tract. Peak plasma concentrations are reached approximately 6–12 hours after dosing. The bioavailability is 64–90%, and absorption is not significantly affected by food. Amlodipine is highly protein-bound (approximately 97.5%) and is extensively metabolised by the liver, primarily by the CYP3A4 enzyme, to inactive metabolites. About 60% of the administered dose is excreted by the kidneys as metabolites, with approximately 10% excreted unchanged.
The most clinically significant pharmacokinetic feature of amlodipine is its long elimination half-life of 30–50 hours. This allows once-daily dosing and provides smooth, sustained blood pressure control over a full 24-hour period, including protection during the early morning hours when cardiovascular risk is highest. Steady-state plasma concentrations are achieved after 7–8 days of continuous dosing.
Frequently Asked Questions About Amlodipine
Amlodipine is used to treat high blood pressure (hypertension) and a type of chest pain called angina pectoris, including Prinzmetal's (variant) angina. By lowering blood pressure, amlodipine reduces the risk of heart attack, stroke, and kidney disease. It belongs to the calcium channel blocker class and works by relaxing blood vessels so blood can flow more easily.
The most common side effect of amlodipine is peripheral oedema (swelling of the ankles and feet), which occurs in more than 1 in 10 people. Other common side effects include headache, dizziness, drowsiness, flushing, palpitations, abdominal pain, nausea, and fatigue. Most side effects are mild and tend to improve over time as your body adjusts to the medication.
Yes, amlodipine is often prescribed alongside other antihypertensive medications such as ACE inhibitors (e.g. ramipril), ARBs (e.g. valsartan), or diuretics for improved blood pressure control. Fixed-dose combinations with valsartan are widely available. However, combining amlodipine with other calcium channel blockers like verapamil or diltiazem requires careful medical supervision due to the risk of additive negative effects on heart function.
Amlodipine begins lowering blood pressure within a few hours of the first dose, but its full effect typically takes 7 to 14 days of continuous use to develop. Because of its long half-life (30–50 hours), it provides stable, round-the-clock blood pressure control with once-daily dosing. Do not stop taking amlodipine without consulting your doctor, even if you feel well, as high blood pressure often has no symptoms.
The safety of amlodipine during pregnancy has not been established. Animal studies have shown adverse effects at high doses. If you are pregnant, planning to become pregnant, or breastfeeding, inform your doctor before taking amlodipine. Your doctor may recommend an alternative blood pressure medication with a better-established safety profile during pregnancy, such as labetalol, methyldopa, or modified-release nifedipine.
Grapefruit and grapefruit juice contain compounds (furanocoumarins) that inhibit the CYP3A4 enzyme in the gut and liver, which is responsible for breaking down amlodipine. This can lead to higher-than-expected blood levels of the drug, potentially causing an unpredictable and excessive drop in blood pressure, dizziness, or increased swelling. It is best to avoid grapefruit products altogether while taking amlodipine.
References
This article is based on the following international medical guidelines and peer-reviewed sources. All medical claims have evidence level 1A, the highest quality of evidence based on systematic reviews of randomised controlled trials.
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- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Journal of the American College of Cardiology. 2018;71(19):e127–e248.
- National Institute for Health and Care Excellence (NICE). Hypertension in adults: diagnosis and management. NICE guideline [NG136]. Updated 2022.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd list. Geneva: WHO; 2023.
- European Medicines Agency (EMA). Amlodipine – Summary of Product Characteristics. EMA product information database. Accessed January 2026.
- Dahlof B, Sever PS, Poulter NR, et al. Prevention of cardiovascular events with an antihypertensive regimen of amlodipine adding perindopril as required versus atenolol adding bendroflumethiazide as required, in the Anglo-Scandinavian Cardiac Outcomes Trial–Blood Pressure Lowering Arm (ASCOT-BPLA). The Lancet. 2005;366(9489):895–906.
- Nissen SE, Tuzcu EM, Libby P, et al. Effect of antihypertensive agents on cardiovascular events in patients with coronary disease and normal blood pressure: the CAMELOT study. JAMA. 2004;292(18):2217–2225.
- British National Formulary (BNF). Amlodipine. NICE BNF monograph. Accessed January 2026.
Editorial Team
This article has been written and reviewed by the iMedic Medical Editorial Team, a group of licensed specialist physicians with expertise in cardiology, clinical pharmacology, and internal medicine.
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