Amlodipine Besylate

Indications

Amlodipine Besylate is used to treat high blood pressure (hypertension) and to prevent chest pain caused by narrowed heart arteries (stable angina and vasospastic or Prinzmetal angina). Lowering blood pressure reduces the risk of stroke, heart attack and kidney damage. It can be used alone or with other blood pressure medicines.

How It Works

Amlodipine is a calcium channel blocker. It reduces the entry of calcium into the muscle cells of blood vessel walls, which makes the vessels relax and widen. This lowers blood pressure and reduces the work the heart has to do, and it improves blood flow to the heart muscle, which helps prevent angina. Its effect builds up gently and lasts a full day.

Dosage and Administration

Adults: the usual starting dose is 5 mg once daily, which the doctor may increase to a maximum of 10 mg once daily. Older people, small or frail patients and those with liver problems may start at 2.5 mg once daily. Take it at the same time each day, with or without food. It may take 1 to 2 weeks to see the full effect. Keep taking it even if you feel well, and do not stop suddenly without advice.

Interactions

Medicines that block the liver enzyme CYP3A4, such as Ketoconazole, Itraconazole, Clarithromycin, Ritonavir and Diltiazem, can raise amlodipine levels; large amounts of grapefruit juice can do the same. Rifampicin, Carbamazepine and St John's Wort may reduce its effect. Amlodipine can raise levels of Simvastatin (keep Simvastatin at 20 mg daily or less), Cyclosporine and Tacrolimus. Other blood pressure medicines, alcohol and Sildenafil can add to the lowering of blood pressure.

Contraindications

• Allergy to Amlodipine or other dihydropyridine calcium channel blockers.
• Very low blood pressure or shock, including cardiogenic shock.
• Severe narrowing of the aortic valve (aortic stenosis).
• Unstable heart failure after a heart attack.

Side Effects

Common effects include ankle and foot swelling, headache, flushing, tiredness, dizziness, palpitations, nausea and stomach pain. Swollen gums can occur with long-term use; good dental care helps.

Get urgent medical help if you have chest pain that is new or worse than usual, fainting, a very fast or irregular heartbeat, yellow skin or eyes, a severe skin rash with blisters, or swelling of the face, lips or throat with difficulty breathing.

Pregnancy and Lactation

Safety in pregnancy is not fully established; use only if your doctor considers it the best option, as other medicines are often preferred. Small amounts pass into breast milk; discuss with your doctor whether to continue breastfeeding.

Precautions and Warnings

Use with caution in people with liver disease, heart failure and in older people. Stand up slowly if you feel dizzy, and do not drive if you feel dizzy or tired. Have your blood pressure checked regularly. Ankle swelling is not usually due to fluid overload and does not always respond to water tablets; tell your doctor if it is troublesome.

Overdose

Overdose can cause a severe drop in blood pressure, fast heartbeat, flushing and fluid in the lungs, which may appear many hours later. Go to a hospital immediately, even if you feel well at first.

Therapeutic Class

Calcium channel blocker (dihydropyridine), antihypertensive and antianginal.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.