Fusidic Acid: A Neglected Risk Factor for Statin-Associated Myopathy.

BACKGROUND

Statins are widely used lipid-lowering drugs used for the prevention of cardiovascular disease. Statins are known to cause myopathy, an adverse drug reaction with various clinical features rhabdomyolysis.

OBJECTIVE

To describe clinical characteristics of statin-treated individuals who experienced myopathy and identify risk factors of statin-associated myopathy.

METHODS

A retrospective study was conducted on cases of statin-associated myopathy reported to the Swedish Medical Products Agency. Clinical factors were compared between cases and statin-treated controls not diagnosed with myopathy. Statistical methods were univariate and multivariate logistic regression and results were presented as odds ratio (OR) with 95% confidence interval (CI). To correct for multiple comparisons, the cutoff for statistical significance was set to  < .0017.

RESULTS

In total, 47 cases of statin-associated myopathy were compared with 3871 treated controls. Rhabdomyolysis was diagnosed in 51% of the cases. Markers for cardiovascular disease were more common in cases than controls. Statistical analysis revealed the following independent risk factors for myopathy: high statin dose (OR = 1.54, calculated using the standard deviation 19.82, 95% CI = 1.32-1.80,  < .0001), and concomitant treatment with fusidic acid (OR = 1002, 95% CI = 54.55-18 410,  < .0001), cyclosporine (OR = 34.10, 95% CI = 4.43-262.45,  = .0007), and gemfibrozil (OR = 12.35, 95% CI = 2.38-64.10,  = .0028).

CONCLUSIONS

The risk of myopathy increases with statin dose and cotreatment with cyclosporine and gemfibrozil. Concomitant fusidic acid has previously only been noted in a few case reports. Considering that use of fusidic acid may become more frequent, it is important to remind of this risk factor for statin-associated myopathy.