Kolchin

Indications

Colchicine is used to treat sudden attacks (flares) of gout, a painful swelling of the joints caused by uric acid crystals, and to prevent gout flares, especially when starting medicines that lower uric acid such as Allopurinol. It is also used for familial Mediterranean fever and, on specialist advice, for pericarditis (inflammation of the lining around the heart) and some other inflammatory conditions.

How It Works

Colchicine reduces the movement and activity of white blood cells (neutrophils) that rush to the joint and cause inflammation when uric acid crystals are present. It does this by blocking tubulin, a protein these cells need to move. It eases pain and swelling but does not lower uric acid levels.

Dosage and Administration

For a gout flare in adults: 1 mg (two 0.5 mg tablets) at the first sign of a flare, followed by 0.5 mg one hour later; do not take more than 1.5 mg in the first day, and do not repeat a course within 3 days unless your doctor advises. Some doctors use 0.5 mg two to three times a day instead; follow your prescription. To prevent flares: usually 0.5 mg once or twice a day. Lower doses are needed in older people and in kidney or liver disease. Other uses: as prescribed.

Interactions

Medicines that block the enzyme CYP3A4 or the P-glycoprotein pump can raise colchicine to dangerous levels. These include Clarithromycin, Erythromycin, Ketoconazole, Itraconazole, Ritonavir, Ciclosporin, Verapamil and Diltiazem, and grapefruit juice. Statins such as Simvastatin and fibrates increase the risk of muscle damage. Always check with a doctor or pharmacist before starting any new medicine.

Contraindications

Do not use colchicine if you are allergic to it, have serious blood disorders, or have kidney or liver disease while also taking a medicine that blocks CYP3A4 or P-glycoprotein. It should be avoided in severe kidney or liver disease unless a specialist advises.

Side Effects

Common side effects are diarrhoea, nausea, vomiting and stomach pain, especially at higher doses; stop taking it and contact your doctor if diarrhoea or vomiting occur during a flare course. Less common effects with long-term use include muscle weakness or pain, numbness or tingling, hair loss and low blood counts.

Get urgent medical help if you have severe or bloody diarrhoea, severe vomiting, muscle pain or weakness, unusual bleeding or bruising, fever, sore throat or signs of infection, numbness, very little urine, or signs of a serious allergic reaction.

Pregnancy and Lactation

Colchicine is used in pregnancy only when the benefit outweighs the risk, mainly for familial Mediterranean fever under specialist care. Small amounts pass into breast milk; it is usually considered acceptable for breastfeeding in normal doses, but ask your doctor.

Precautions and Warnings

Colchicine has a narrow safety margin, so never take more than prescribed. Use with care in older people and in kidney, liver, heart or stomach disease. Blood counts may be checked during long-term use. Avoid grapefruit and grapefruit juice. Both men and women should discuss fertility with their doctor if planning a family.

Overdose

Colchicine overdose is very dangerous and can be fatal, sometimes with symptoms that begin hours later. Early signs include severe vomiting, diarrhoea and stomach pain, followed by organ failure, bone marrow failure and breathing problems. Go to hospital immediately, even if the person feels well.

Therapeutic Class

Antigout agent, anti-inflammatory (microtubule inhibitor).

Storage

Store below 30°C in a dry place, away from light and out of the reach of children. Keep tablets in the original pack, as small amounts can be very harmful to children.