Colchicine

What is colchicine?

Colchicine is an ancient drug that is made from autumn saffron, Autumnal colchicum (a poisonous European flowering plant). It has been used mainly in the treatment of gout. Although not formally indicated or approved for the treatment of dermatological conditions, colchicine has been prescribed for some skin conditions with good results. Its effectiveness is due to several immune and antiinflammatory properties.

In New Zealand, colchicine is available as 0.5 mg (or 500 microgram) tablets (previously 0.6 mg).

For its potential toxicity, colchicine is used as a second-line agent when safer medications have not been successful.

Colchicine for dermatological diseases.

Colchicine is used for some dermatological diseases. Its effectiveness has only been demonstrated through the treatment of small and mostly uncontrolled study groups.

Other dermatological conditions that can be treated with colchicine include linear IgA skin disease, acquired epidermolysis bullosa, vasculitis, morpho and dermatomyositis.

More controlled and double-blind Studies are needed to demonstrate the usefulness of colchicine in dermatological diseases.

Contraindications to colchicine

Colchicine should not be used in the following circumstances:

• Knowledgeable patients hypersensitivity (allergy) to medicine
• Patients with severe gastrointestinal, kidney, liver or heart disorders.
• Patients with blood diseases in which there is a low number of white blood cells or platelets
• Patients taking statins (cholesterol-low intensity drugs)
• Pregnant women

Precautions when using colchicine

Colchicine can be fatal in an overdose. Colchicine treatment should be stopped immediately when abdominal pain, diarrhea, nausea or vomiting occurs. These are the first signs of toxicity and usually occur between 0 and 24 hours after taking the drug.

If you are taking other medications, particularly antibiotics and pain relievers, do not take colchicine before checking with your doctor or pharmacist that it is safe to do so.

Colchicine Side Effects.

The most common side effects are abdominal pain, diarrhea, nausea, or vomiting, which occur in up to 80% of patients receiving a maximum dose. Gastrointestinal symptoms are worse with higher doses. These symptoms indicate toxicity and the drug should be discontinued.

Toxicity results in:

• Bone marrow depression resulting in agranulocytosis (absence of white blood cells) and thrombocytopenia (low platelet count)
• Peripheral neuritis (nerve inflammation affecting hands and feet)
• Purple (bleeding into the skin)
• Myopathy (weak muscles)
• waste of hair
• Azoospermia (absence of sperm production).
• Seizures
• Cardiac arrhythmia (palpitations) and low blood pressure
• Lung, kidney and liver failure

Colchicine, when used in low doses, has a low rate of side effects. The beneficial effects without the side effects are possible by reducing the dose. However, there is no antidote if you take an excessive dose. Seek medical help immediately.