Colchicine

What is Colchicine 0.5 mg?

Colchicine is an oral prescription medicine containing colchicine as its active substance. It is used to treat gout and certain inherited inflammatory disorders.

Gout is a type of inflammatory arthritis caused by the build-up of uric acid crystals in the joints. When these crystals form, the immune system reacts strongly, leading to sudden pain, redness and swelling.

Colchicine does not remove uric acid from the body. Instead, it reduces the body’s inflammatory response to these crystals. This helps relieve symptoms during an attack and can reduce the risk of further flare ups when used preventively.

Colchicine has a narrow therapeutic window. This means that even small dosing errors can increase the risk of side effects. For this reason, it should only be used exactly as prescribed.

What is Colchicine used for?

Colchicine is used in adults for:

• Treatment of acute gout attacks
• Prevention of recurrent gout attacks
• Prevention of gout flares when starting urate lowering therapy

Colchicine is also used in the management of familial Mediterranean fever, a hereditary inflammatory disorder that causes repeated episodes of fever and inflammation affecting the abdomen, chest or joints.

In patients with FMF, long term colchicine treatment can significantly reduce the frequency of attacks and lower the risk of amyloidosis, a serious complication that can affect organs such as the kidneys.

Colchicine is not a general pain reliever. It specifically targets inflammation related to crystal deposition or inherited inflammatory conditions.

How does Colchicine work?

When uric acid crystals deposit in a joint, immune cells move into the affected area and release inflammatory substances. This immune response causes swelling, warmth and pain.

Colchicine works inside these immune cells. It interferes with microtubule formation, which reduces the movement and activation of inflammatory cells. As a result, the inflammatory reaction becomes less intense and symptoms improve.

Because colchicine is processed in the liver and partly eliminated by the kidneys, impaired organ function or certain drug interactions can increase the risk of toxicity.

Who should not take Colchicine?

Do not use colchicine if you:

• Are allergic to colchicine or any of the tablet ingredients
• Have severe kidney impairment
• Have severe liver impairment
• Have serious blood disorders

Colchicine must not be used in patients with kidney or liver impairment who are also taking strong inhibitors of CYP3A4 or P glycoprotein, as this can lead to dangerously high colchicine levels.

It must also not be combined with certain medicines that significantly increase colchicine concentrations, including:

• Macrolide antibiotics such as clarithromycin or erythromycin
• Azole antifungals such as ketoconazole or itraconazole
• Certain calcium channel blockers such as verapamil or diltiazem
• Ritonavir and other strong antiviral inhibitors
• Ciclosporin

These combinations can result in severe or life threatening toxicity.

Pregnancy and fertility

Use during pregnancy requires specialist medical supervision. The benefits and risks must be assessed individually, particularly in patients with familial Mediterranean fever where continuation may be necessary.

Breastfeeding should only occur under medical advice.

Men are generally advised not to father a child during treatment and for at least six months after stopping colchicine.

Colchicine dosage and how to take it

Always take colchicine exactly as prescribed by your doctor. Never exceed the prescribed dose.

Acute gout attack

The usual adult dose is 0.5 mg two to three times daily. An initial dose of 1 mg may be given at the start of treatment.

Treatment should be stopped if:

• Significant gastrointestinal symptoms occur
• No improvement is seen after two to three days
• A total dose of 6 mg has been reached in one treatment course

Do not repeat a treatment course within three days.

Prevention of gout attacks

The usual preventive dose is 0.5 mg to 1 mg daily.

Familial Mediterranean fever

The typical adult dose ranges from 1 mg to 3 mg daily. Doses above 1 mg are usually divided during the day. The maximum recommended daily dose is 3 mg.

Because colchicine overdose can be fatal, precise adherence to the prescribed dosing schedule is essential.

Colchicine side effects

Gastrointestinal side effects are common and may be early signs of toxicity.

Very common or common side effects include:

• Nausea
• Vomiting
• Abdominal pain
• Diarrhoea

If these symptoms occur, medical advice should be sought.

Less common but serious side effects include:

• Bone marrow suppression leading to reduced white blood cells, anaemia or low platelets
• Muscle pain or weakness
• Rhabdomyolysis, a severe form of muscle breakdown
• Liver dysfunction
• Kidney dysfunction
• Hair loss
• Vitamin B12 deficiency

Symptoms such as fever, sore throat, unusual bruising or bleeding require urgent medical evaluation.

Important safety information

Colchicine has a small safety margin. Taking more than prescribed, even accidentally, can be dangerous.

Certain medicines can increase colchicine levels in the blood and raise the risk of toxicity. These include some antibiotics, antifungal medicines, antiviral medicines and heart medications. Always inform your doctor about any medicines you are taking.

Grapefruit and grapefruit juice should be avoided during treatment, as they can increase the amount of colchicine in your bloodstream.

If you have kidney or liver problems, your dose may need to be adjusted. In severe cases, colchicine may not be suitable.

When to seek urgent medical help

Seek urgent medical attention if you experience:

• Severe or persistent diarrhoea
• Persistent abdominal pain
• Signs of infection such as fever or sore throat
• Unusual bruising or bleeding
• Muscle pain combined with weakness
• Dark coloured urine
• Suspected overdose

Colchicine toxicity can develop quickly and requires urgent medical care.

If you believe colchicine may be appropriate for your condition, you can complete an online medical questionnaire. An EU licensed doctor will review your information to determine whether this treatment is suitable and safe for you. If approved, your prescription will be dispensed by a regulated EU pharmacy and delivered discreetly.