Colchicine (Cardiovascular Anti-Inflammatory)

How it works

It binds tubulin and disrupts microtubule assembly, impairing neutrophil chemotaxis and inflammasome activation, thereby dampening the vascular inflammation that contributes to atherosclerotic events.

Prescribing in practice

• Colchicine has a narrow therapeutic margin and is dangerous in overdose, so the dose must be reduced or avoided in significant renal or hepatic impairment to prevent toxicity.
• It is a substrate of CYP3A4 and P-glycoprotein, so combining it with strong inhibitors such as clarithromycin, ciclosporin or verapamil can precipitate serious toxicity.
• Diarrhoea is an early warning sign of toxicity and should prompt dose review.

Monitoring

Monitor renal and hepatic function and the full blood count during longer-term use, and review for gastrointestinal symptoms, neuromyopathy and interacting drugs.

Counselling the patient

• Stop and seek advice if you develop diarrhoea, vomiting or muscle weakness.
• Avoid grapefruit juice and tell clinicians before starting new medicines.
• Never exceed the prescribed dose, as overdose can be fatal.

Evidence & guidelines

The COLCOT and LoDoCo2 trials showed low-dose colchicine reduced cardiovascular events in coronary disease, but it is not currently licensed for this purpose in the UK.