G-Metoprolol

Indications

Metoprolol tartrate is used to treat high blood pressure and angina (chest pain from the heart), to control some fast or irregular heart rhythms, and to protect the heart after a heart attack. It is also used to prevent migraine and to ease symptoms of an overactive thyroid, such as a fast heartbeat.

How It Works

It is a beta blocker. It blocks the effect of adrenaline on the heart, so the heart beats more slowly and with less force. This lowers blood pressure and reduces the heart's need for oxygen.

Dosage and Administration

Adults, high blood pressure: often 50 mg twice a day to start; the usual range is 100 to 200 mg a day in divided doses. Angina: commonly 50 to 100 mg two or three times a day. Migraine prevention: usually 100 to 200 mg a day in divided doses. Other uses, including after a heart attack, and injections given by a doctor or nurse in hospital: as prescribed. Take with or just after food, in the same way each day. Do not stop suddenly; the doctor will lower the dose over 1 to 2 weeks.

Interactions

• Verapamil and Diltiazem can cause a very slow heartbeat or heart failure when combined with it.
• Other blood pressure medicines and alcohol can lower blood pressure too much.
• If it is taken with Clonidine, the doctor will advise how to stop the two medicines safely.
• Amiodarone, Digoxin and other heart rhythm medicines increase the risk of a slow heartbeat.
• Fluoxetine, Paroxetine, Bupropion and Quinidine can raise metoprolol levels; Rifampicin can lower them.
• Pain killers such as Ibuprofen can reduce its effect on blood pressure.
• It can hide the warning signs of low blood sugar in people using Insulin or diabetes tablets.

Contraindications

• Very slow heartbeat, or certain heart blocks (unless a pacemaker is fitted).
• Uncontrolled heart failure or shock caused by heart problems.
• Very low blood pressure or severe circulation problems in the legs or arms.
• Untreated phaeochromocytoma (an adrenal gland tumour).
• Allergy to metoprolol or any ingredient of the product.

Side Effects

Common: tiredness, dizziness, headache, cold hands and feet, slow pulse, nausea, stomach upset, and sleep problems or vivid dreams.

Get urgent medical help for:

• A very slow pulse with fainting or severe dizziness.
• Wheezing or difficulty breathing.
• Rapid swelling of the legs, sudden weight gain or breathlessness when lying flat.
• Chest pain that is new or getting worse.
• Swelling of the face or throat, or a severe rash.

Pregnancy and Lactation

It can be used in pregnancy if the doctor decides it is needed. The baby may need checks for slow heartbeat and low blood sugar after birth. Small amounts pass into breast milk; it is usually considered compatible with breastfeeding, but watch the baby for unusual sleepiness or poor feeding.

Precautions and Warnings

• Stopping suddenly can bring on severe chest pain or a heart attack.
• Use with care in asthma or COPD; it should be used only if a doctor decides it is safe.
• Tell the doctor about diabetes, thyroid disease, liver disease, psoriasis or circulation problems.
• Tell the surgeon or anaesthetist before any operation.
• It may cause dizziness or tiredness; take care when driving.

Overdose

Signs include a very slow pulse, very low blood pressure, fainting, breathing difficulty and fits. Get emergency medical help at once.

Therapeutic Class

Cardioselective beta blocker.

Storage

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