DRUG-RELATED MYOPATHIES

When Statins Get Physical: A Curious Cause of Statin Myopathy

We present the case of a 61-year-old male with hyperlipidemia and lumbar radiculopathy admitted to our hospital with rhabdomyolysis attributed to the recent initiation of statin therapy. Despite aggressive fluid resuscitation and an initial declination in his creatine phosphokinase (CPK) levels, he had persistent myalgias with progressive weakness. Rheumatologic and neurologic evaluation for other causes of myopathy were negative. Muscle biopsy obtained showed signs of necrosis and muscle regeneration. Given his recent statin use, persistent CPK elevation, proximal muscle weakness, and muscle biopsy findings, he was diagnosed as having statin-induced necrotizing autoimmune myopathy. He improved with the initiation of immunosuppressive therapy. Statin-induced necrotizing autoimmune myopathy is an underdiagnosed cause of myalgias, proximal muscle weakness, and significant CPK elevation that fails to respond to statin discontinuation and fluid resuscitation. Given the prevalence of statin use, internists need to have a high index of suspicion for this diagnosis in patients presenting with CPK elevations and muscle weakness who take statin therapy.

Isolated left upper extremity myositis and severe rhabdomyolysis in an adult with H1N1 Influenza, a case report with literature review

Acute viral myositis is a fairly rare condition and usually seen in recovery phase of illness, especially in pediatric or geriatric population. Influenza type A, specifically H1N1 may present with generalized myositis and mild elevation of creatinine kinase in addition to usual manifestations. We would like to discuss an atypical presentation of Type A Influenza (H1N1) in a middle aged male who was never immunized for influenza, presenting with fever, vomiting, anuria and acute severe left upper extremity pain. The most interesting presentation in our patient was that, it was limited to a single extremity, unlike generalized presentation, which was previously reported, acute renal failure warranting renal replacement therapy. This case serves as a reminder for clinicians about atypical manifestations of H1N1 and its threatening metabolic complications. Hence the practitioners should be aware of this rare but possible presentation of certain strains of influenza virus. It also accentuates the importance of being immunized, reminding us of the Old but Golden Adage “Prevention is better than Cure.”

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.

Colchicine-Induced Myopathy in a Teenager with Familial Mediterranean Fever

OBJECTIVE

To report a case of colchicine-induced myopathy in a teenager with familial Mediterranean fever (FMF).

CASE SUMMARY

A 15-year-old boy of Turkish origin, diagnosed as having FMF at the age of 14 years, was treated with colchicine 1.5 mg/d. He had experienced only 2 mild peritonitis attacks with fever within 1 year. The patient used the recommended dose regularly, and he described progressive proximal muscle weakness and generalized myalgias, which started 1 month before presentation. Physical examination showed proximal muscle weakness in his arms and legs. Laboratory tests revealed elevated serum creatine kinase, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. All other laboratory values were within normal range. Electromyographic investigation revealed a myopathic pattern in proximal muscles without any neuropathic changes. A biopsy of the deltoid muscle showed vacuolar degeneration of striated muscle fibers with no inflammatory findings.

DISCUSSION

Colchicine, the most important drug in treatment of FMF, can cause myopathy in patients with impaired renal and hepatic function. In our patient, an objective causality scale showed that therapeutic doses of colchicine for FMF were the definite cause of myopathy, even though his renal and hepatic function were normal. The treatment of FMF attacks in patients who cannot use colchicine is an important problem. There are insufficient data about the use of immunosuppressive agents in the treatment of FMF attacks; however, we now successfully control the attacks with colchicine 0.5 mg/d and azathioprine 2 mg/kg/d.

CONCLUSIONS

Colchicine-induced myopathy should be excluded in patients with FMF who present with generalized muscle weakness. Clinicians should be aware that myopathy can occur in patients with FMF who have normal renal and hepatic function.

Genetic and environmental risk factors for idiopathic inflammatory myopathies

Although the studies discussed are beginning to reveal a number of genetic and possible environmental risk factors for myositis, further investigations are needed to fully understand and classify these syndromes. The difficulties in this process include small numbers of subjects with varying disease phenotypes available for study, polygenic risk factors for which it remains unclear which are primary and which are secondary or linked genes, and the lack of validated environmental exposure assessment tools. New technologies and international collaborative approaches, however, may overcome some of these difficulties and allow us to identify genetic and environmental risk factors, as well as the critical gene-environment interactions in the IIM and its subgroups. Nonetheless, our understanding of these diseases is still in the early stages. Although we have learned a great deal about these disorders through detailed investigations over the last several decades, we have even further to go to understand the environmental triggers and genetic susceptibilities for the myositis syndromes.

Myopathies in the elderly

Muscle disease symptoms and myopathies are not uncommon in the elderly. Inflammatory and noninflammatory myopathies lead to proximal extremity or axial weakness and are superimposed on the intrinsic changes that occur in muscle with aging (sarcopenia). This article surveys the more common myopathies in the elderly based on a review of the process of sarcopenia, and how these age-related changes in muscle structure and function affect the results of the standard assessments of muscle disease in the elderly.