Amlodipine

Amlodipine is a type of medication called a calcium channel blocker. It is used to treat high blood pressure (hypertension) and prevent chest pain caused by angina. Amlodipine also helps to prevent heart disease, heart attacks, and stroke.

The brand name for amlodipine is Istin. It is also available in combination with other medications such as Exforge® (with valsartan) and Sevikar® (with olmesartan).

Amlodipine works by blocking the amount of calcium that enters the muscle cells of your heart and arteries. These muscles need calcium to contract, so reducing the amount of calcium causes them to relax. This dilates (widens) your arteries, lowers your blood pressure, and relaxes your heart muscle, helping to relieve angina pain.

To take amlodipine:

• Swallow your tablet whole with a glass of water. If you prefer, you can dissolve your tablet in water, but make sure you mix it thoroughly and drink it all straight away.
• If you are taking the liquid, measure the amount carefully using the spoon or syringe that comes with the medication. If you do not have the correct measuring device, ask your pharmacist for one. Never use a teaspoon or try to guess the correct amount.
• Take your medicine at the same time every day
• You can take amlodipine with or without food
• Don’t take your medication with grapefruit juice. This can increase the amount of amlodipine in your body and make side effects worse.

The usual starting dose for amlodipine is 5mg once a day, but your doctor may increase this to 10mg once a day if necessary. This can be because your blood pressure is still too high or if you are still experiencing angina pain.

What if I forget to take amlodipine?

If you miss your dose of amlodipine, and it is still the same day, take it as soon as you remember. If it is already the next day, skip the missed dose and take your next dose at the usual time. Never take 2 doses together to make up for the missed dose.

What if I take too much amlodipine?

Taking too much amlodipine can cause your blood pressure to become too low. This may make you feel dizzy, faint, weak, and lightheaded, and even cause you to collapse (lose consciousness).

If you take too much amlodipine, call your doctor or 111 immediately. If you need to go to hospital, do not drive yourself. Take your amlodipine packet, or bottle, including any remaining medication with you.

How quickly does amlodipine work?

Amlodipine is absorbed slowly compared to some other blood pressure medications and normally starts to work after around 8 hours. You may not see the effects of amlodipine for around 3 to 4 weeks. This is because amlodipine builds up in your body by taking it regularly and it takes a while for the levels in your blood to stabilise.

Amlodipine is a highly effective medication and is normally one of the first treatment options for people with mild to moderate high blood pressure. If amlodipine doesn’t work for you, or if you experience troubling side effects from amlodipine, talk to your GP about trying a different medication.

Amlodipine is a safe medication for most people, but it may not be suitable for everyone. Always tell your doctor about any medical conditions and allergies you have before taking amlodipine.

Do not take amlodipine if you:

• are allergic to amlodipine (or any of its ingredients), or other calcium channel blockers
• have low blood pressure (hypotension)
• have narrowing of the heart valve (aortic stenosis)
• have heart failure following a heart attack

Talk to your doctor before taking amlodipine if you:

• are pregnant
• are breastfeeding
• have, or have ever had problems with your liver
• have ever had sudden, severe high blood pressure (hypertensive crisis)

Like all medications, amlodipine can cause side effects in some people.

Common side effects (affecting up to 1 in 10 people) include:

• swollen ankles
• headaches
• dizziness
• nausea (feeling sick) or abdominal discomfort
• feeling hot or flushed
• awareness of your heartbeat, fast or irregular heartbeat (palpitations)

Uncommon side effects (affecting up to 1 in 100 people) include:

• mood changes, anxiety, and depression
• difficulty sleeping
• numbness or tingling in the limbs
• ringing or buzzing in the ears (tinnitus)
• low blood pressure
• sneezing or runny nose
• cough
• dry mouth
• vomiting
• hair loss
• rash
• passing urine (peeing) more often than usual
• erectile dysfunction
• joint or muscle pain
• weight changes

If you experience any of the above side effects while taking amlodipine, do not stop taking your medication, but talk to your GP about trying an alternative treatment.

Rarely, amlodipine can cause serious side effects.

Call your doctor or 111 immediately if you experience:

• itchy rash (hives), reddening of the skin, blisters, peeling or swelling of the skin
• severe stomach pain, nausea, and vomiting
• yellowing of the skin and the whites of the eyes

Call an ambulance immediately if you experience:

• sudden, severe chest pain that lasts longer than a few minutes
• swelling of the face, eyelids, lips, and tongue, difficulty breathing, and rash

Are there any long-term side effects?

Long-term side effects of amlodipine are uncommon, but may include:

• skin changes such as redness, swelling, itching, and dryness
• dry mouth
• increased sweating
• emotional effects like anxiety, depression, sleep problems, and sexual dysfunction
• gastric effects including indigestion, constipation, diarrhoea, difficulty swallowing, vomiting, and gas
• cardiovascular effects such as an irregular heartbeat, fast or slowed heartbeat, and low blood pressure

If you think you are experiencing long-term effects from taking amlodipine, talk to your GP.

Sometimes different medications can interact with each other, which may make side effects worse, or change the way your medication works. Always tell your doctor or pharmacist about any other medications you are taking, including over-the-counter medications, vitamins, and supplements.

Medications known to interact with amlodipine include:

• blood pressure medications like ramipril, or lisinopril
• calcium channel blockers such as verapamil or diltiazem
• some antibiotics including erythromycin and rifampicin
• anti-fungal medications like ketoconazole
• some medications used to treat HIV and Hepatitis C (HCV)
• anti-epilepsy drugs like carbamazepine and phenytoin
• medications that suppress your immune system like ciclosporin or tacrolimus
• over 20mg a day of the cholesterol medication simvastatin
• St John’s wort, a herbal remedy used to treat depression

Amlodipine and grapefruit

Grapefruit can increase the effects of amlodipine. It’s best to avoid grapefruit or anything containing grapefruit while taking amlodipine.

Amlodipine and Viagra

Amlodipine and the erectile dysfunction medication Viagra can both lower your blood pressure, but this rarely causes severe effects.. If you experience dizziness, headache, flushing, fainting, or light-headedness while taking Viagra, talk to your GP.

Amlodipine and aspirin

The combination of amlodipine and low-dose aspirin can cause your blood pressure to increase. If you stop taking aspirin while taking amlodipine it may cause your blood pressure to drop. If you take a low-dose aspirin every day, talk to your doctor before taking amlodipine. Your doctor may want to alter your dose or check your blood pressure more often.

If amlodipine isn’t right for you, there are alternative medications available that may be more suitable. These include:

• other calcium channel blockers like nifedipine, diltiazem, or verapamil
• angiotensin-converting enzyme (ACE) inhibitors like lisinopril, ramipril, or benazepril
• angiotensin receptor blockers (ARBs) such as losartan, telmisartan, or candesartan
• beta blockers like carvedilol, metoprolol, or bisoprolol
• diuretics like hydrochlorothiazide

If amlodipine isn’t right for you, talk to your GP about alternative treatments.