BMA Concise Guide to Medicine & Drugs

Amlodipine

Brand names Amlostin, Istin

Used in the following combined preparations Exforge, Sevikar

QUICK REFERENCE

Drug group Anti-angina drug and antihypertensive drug

Overdose danger rating Medium

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Amlodipine belongs to a group of drugs known as calcium channel blockers, which interfere with the conduction of signals in the muscles of the heart and blood vessels.

Amlodipine is used in the treatment of angina to help prevent attacks of chest pain. Unlike some other anti-angina drugs (such as beta blockers), it can be used safely by people with asthma and non-insulin-dependent diabetes.

Amlodipine is also used to reduce raised blood pressure (hypertension).

In common with other drugs of its class, amlodipine may cause blood pressure to fall too low at the start of treatment. In rare cases, angina may become worse at the start of amlodipine treatment. The drug may sometimes cause mild to moderate leg and ankle swelling.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets.

Frequency and timing of doses Once daily.

Adult dosage range 5–10mg daily.

Onset of effect 6–12 hours.

Duration of action 24 hours.

Diet advice Avoid grapefruit juice, because it may interact with amlodipine and increase the drug’s effects.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose If you miss a dose and you remember it within 12 hours, take it as soon as you remember. However, if you do not remember until later, do not take the missed dose and do not double up the next one. Instead, go back to your regular schedule.

Stopping the drug Do not stop taking the drug without consulting your doctor; stopping the drug may lead to worsening of the underlying condition.

Exceeding the dose An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause a marked lowering of blood pressure. Notify your doctor immediately.

POSSIBLE ADVERSE EFFECTS

Amlodipine can cause a variety of minor adverse effects, including leg and ankle swelling, headache, dizziness (especially when rising from sitting or lying down, when it may be the result of an excessive reduction in blood pressure), fatigue, and flushing. If any of these become severe, discuss with your doctor. You should also consult your doctor if you have palpitations, nausea, abdominal pain, a rash, or breathing difficulties; if you have a rash or breathing difficulties, you should also stop taking the drug. The most serious adverse effect is the rare possibility of angina becoming worse after starting amlodipine treatment. If this occurs, you should stop taking the drug and consult your doctor immediately.

INTERACTIONS

Ketoconazole, itraconazole, and ritonavir These drugs may increase blood levels and adverse effects of amlodipine.

St John’s wort This reduces the blood level of amlodipine.

Grapefruit juice This may increase the effects of amlodipine.

Alpha blockers, beta blockers, ACE inhibitors, and diuretics Amlodipine may increase the effects of these drugs and vice versa.

Antimalarials Taken with amlopidine, some antimalarials may cause abnormally slow heart beat.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have long-term liver problems.

· You have heart failure or aortic stenosis.

· You have diabetes.

· You are taking other medicines.

Pregnancy Safety in pregnancy not established. Discuss with your doctor.

Breast-feeding It is not known if the drug passes into the breast milk. Discuss with your doctor.

Infants and children Not recommended.

Over 60 No special problems.

Driving and hazardous work Avoid such activities until you have learned how amlodipine affects you because the drug can cause dizziness owing to lowered blood pressure.

Alcohol Avoid. Alcohol may further reduce blood pressure, causing dizziness or other symptoms.

Surgery and general anaesthetics Amlodipine may interact with some general anaesthetics, causing a fall in blood pressure. Discuss this with your doctor or dentist before any surgery.

PROLONGED USE

No problems expected.