Use of statins and fibrates in hyperlipidemic patients with neuromuscular disorders

Polymyosites induites ou associées aux traitements hypolipémiants ?

PURPOSE

Rhabdomyolysis and myositis are rare, dose-related complications of statins and fenofibrates. The outcome is favorable as a rule with rapid regression after stopping the responsible drug. Recently, various auto-immune disease with evidence of hypersensitivity to HMG-CoA reductase inhibitors or fibrates drugs have been reported. Less than ten cases of dermatomyositis and polymyositis due to cholesterol-lowering drugs (CLD) have been previously reported. Five more cases polymyositis associated with CLD are reported.

METHODS

Symptoms were compatible with diagnosis of polymyositis according to Bohan and Peter and with previous reported criteria for drug-induced myopathy in all cases. None of these patients had previous other connective tissue disorders.

RESULTS

Five patients (median age 68 [54-78], female N =4) with CLD treatment (statin N =4, fenofibrates N =1) have developed iatrogenic polymyositis. All of them presented both proximal muscular weakness and increased muscle enzyme levels. One patient had iatrogenic antisynthetase syndrome characterized by mechanic's hand, Raynaud's phenomenon and anti JO1 antibodies. One other had sclerodermic hand oedema. Antinuclear antibodies were positive in 4 cases and muscle biopsy revealed polymyositis infiltrate in 4 cases. CLD treatment was discontinued with partial clinical improvement in 3 cases. Clinical remission was obtained with corticosteroid (N =5) in association with immunosuppresive agents in 3 cases.

CONCLUSION

Muscular symptoms in patient with CLD treatment could be the first symptom of a polymyositis revealed or increased by this treatment and must encourage physician with antinuclear antibodies screening especially in case of proximal muscular weakness and increased muscle enzyme levels.

Drug-induced rheumatic syndromes

Rheumatic syndromes related to drug therapies have been described for decades. The introduction of many new therapeutic agents in recent years has been accompanied by an increase in such reported associations. By definition, drug-induced syndromes are temporally related to starting a drug, and the symptoms and signs generally regress with its discontinuation. The classic and still most common cases resemble systemic lupus erythematosus or scleroderma. Some newer agents appear related to myositis or vasculitis. The origins of most of these syndromes remain obscure.

Lipid-lowering agents and myopathy

Each of the lipid-lowering agents available today can cause myopathy. The severity of the muscle disorder may vary from trivial myalgias or elevations of creatine kinase in asymptomatic individuals to rhabdomyolysis with myoglobinuria, renal failure, and death. Fortunately, significant myopathy occurs at a low rate. However, the large number of individuals taking these medications renders it a significant problem. Although the pathophysiology of the myopathy remains speculative, its occurrence appears to be dose related. Consequently, the total dosage of lipid-lowering drug consumed, the concomitant use of other medications that affect their blood levels, and the individual's specific drug-metabolizing enzyme profile may contribute to this toxicity.

3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors and rhabdomyolysis: considerations in the renal failure patient

An intense debate has developed as to the risk-benefit ratio of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) following the withdrawal of cerivastatin. The development of rhabdomyolysis in cerivastatin-treated patients should have surprised few since myotoxicity is an accepted class effect of statins. What has sprung from the cerivastatin experience though is a concern for other members of this class. Such misgivings, although understandable, are ill advised. Without question, differences exist in the risk of rhabdomyolysis occurrence amongst the various statins. In this regard, pravastatin and fluvastatin are least likely to produce rhabdomyolysis, which, in part, relates to the fact they are not metabolized by the cytochrome P450 3A4 pathway. When muscle damage occurs with statins it is most often the result of a drug-drug interaction rather than a specific adverse response to statin monotherapy. Such drug-drug interactions increase plasma concentrations of a statin and thereby increase the risk of myotoxicity. A growing consensus exists which supports an expanded use of statins in a range of patient groups including the renal failure patient. Polypharmacy and altered drug metabolism increase the risk of myotoxicity, albeit to an ill-defined degree, in this population. Many factors should enter into the choice of a statin in the multiply medicated renal failure patient.