From the Guidelines
No, routine monitoring of Creatine Kinase (CK) levels in patients on colchicine is not generally recommended in New Zealand clinical practice. Colchicine is commonly prescribed for conditions like gout and familial Mediterranean fever, and while it can rarely cause myopathy (muscle damage), this is not frequent enough to warrant routine CK monitoring in all patients. Instead, clinicians should monitor for clinical symptoms of myopathy such as muscle pain, weakness, or tenderness, particularly in patients with risk factors like renal impairment, advanced age, or those taking interacting medications (especially statins) 1. If a patient on colchicine develops these symptoms, then CK testing would be appropriate to investigate for myopathy. The risk of colchicine-induced myopathy increases with higher doses, prolonged treatment, and in patients with reduced drug clearance. Some key points to consider in the management of patients on colchicine include:
- Monitoring for clinical symptoms of myopathy, rather than relying on routine CK testing
- Being aware of the potential for drug interactions, particularly with statins, and adjusting doses accordingly 1
- Educating patients about the potential symptoms of myopathy and advising them to seek medical attention if they develop
- Considering the individual patient's risk factors and adjusting the monitoring and management plan accordingly. It's also important to note that the European League Against Rheumatism (EULAR) recommendations for the management of familial Mediterranean fever suggest that liver enzymes should be monitored regularly in patients with FMF treated with colchicine, and that colchicine dose should be reduced if liver enzymes are elevated greater than twofold the upper limit of normal 1. However, routine CK monitoring is not specifically recommended in these guidelines. Overall, a balanced approach to monitoring and managing patients on colchicine is necessary, taking into account the individual patient's risk factors and the potential benefits and risks of treatment.
From the Research
Routine Checking of Creatine Kinase (CK) Levels in Patients on Colchicine in New Zealand
There is no direct evidence to suggest that routine checking of CK levels is a standard practice for patients on colchicine in New Zealand. However, several studies highlight the importance of monitoring for colchicine toxicity, particularly in patients with renal impairment.
- Colchicine myotoxicity is a rare but well-documented adverse effect, often associated with renal impairment and elevated CK levels 2, 3, 4, 5.
- Patients with renal insufficiency are at increased risk of developing colchicine-induced myoneuropathy, characterized by proximal muscle weakness, elevated serum CK levels, and neuropathy or myopathy on electromyography (EMG) 2, 3, 4, 5.
- The diagnosis of colchicine toxicity can be confirmed by the normalization of CK levels and EMG after discontinuation of the drug 3.
- Clinicians should be aware of the risk factors for colchicine toxicity, including renal impairment, specific drug interactions (e.g., cyclosporine, statins), and high doses of the drug 6, 4.
Key Findings
- Elevated CK levels are a common feature of colchicine myotoxicity 2, 3, 4, 5.
- Patients on colchicine should be monitored for signs of neuromuscular toxicity, particularly those with renal impairment or taking interacting medications 4, 5.
- The therapeutic index of colchicine is narrow, and dosage adjustment or alternative therapy may be required in patients at risk of toxicity 2, 6.