Myoglobinuria in boys with Duchenne muscular dystrophy on corticosteroid therapy

Myoglobinuria is a recognised complication of Duchenne muscular dystrophy (DMD), but has only once been reported in ambulant boys on corticosteroid therapy [Dubowitz V, Kinali M, Main M, Mercuri E, Muntoni F. Remission of clinical signs in early Duchenne muscular dystrophy on intermittent low-dosage prednisolone therapy. Eur J Paediatr Neurol 2002;6(3):153-9.]. We present three prednisolone-treated boys with myoglobinuria and in two cases this was recurrent. All three showed improved motor performance in response to the introduction of corticosteroids. The greater activity of steroid-treated individuals may place their dystrophin-deficient muscles under greater mechanical stress, predisposing to further muscle fibre damage and consequent myoglobinuria. Families and physicians need to have an increased awareness of this possibility and of the appropriate management of myoglobinuria.

Severe rhabdomyolysis after excessive bodybuilding

A 46-year-old male subject performed excessive physical exertion during 4-6 h in a studio for body builders during 5 days. He was not practicing sport prior to this training and denied the use of any aiding substances. Despite muscle aching already after 1 day, he continued the exercises. After the last day, he recognized tiredness and cessation of urine production. Two days after discontinuation of the training, a Herpes simplex infection occurred. Because of acute renal failure, he required hemodialysis. There were absent tendon reflexes and creatine kinase (CK) values up to 208 274 U/L (normal: <170 U/L). After 2 weeks, CK had almost normalized and, after 4 weeks, hemodialysis was discontinued. Excessive muscle training may result in severe, hemodialysis-dependent rhabdomyolysis. Triggering factors may be prior low fitness level, viral infection, or subclinical metabolic myopathy.

Rhabdomyolysis

Rhabdomyolysis is a syndrome involving the breakdown of skeletal muscle causing myoglobin and other intracellular proteins and electrolytes to leak into the circulation. The development of rhabdomyolysis is associated with a wide variety of diseases, injuries, medications and toxins. While the exact mechanisms responsible for all the causes are not fully understood, it is clear that muscle damage can occur from direct injury or by metabolic inequalities between energy consumption and energy production. Rhabdomyolysis is diagnosed by elevations in serum creatine phosphokinase (CPK), and while there is no established serum level cut-off, many clinicians use five times the upper limit of normal ( approximately 1000 U/l). Rhabdomyolysis can be complicated by acute renal failure (occurring in 4%-33% of patients), compartment syndrome, cardiac dysrhythmias via electrolyte abnormalities, and disseminated intravascular coagulopathy. The mainstay of treatment is hospitalisation with aggressive intravenous fluid (IVF) resuscitation with the correction/prevention of electrolyte abnormalities. There are additional adjunctive therapies to IVF, such as alkalinisation of the urine with sodium bicarbonate, diuretic therapy or combinations of both; however the lack of large randomised control studies concerning the benefits of these treatments makes it difficult to make strong recommendations for or against their use in the treatment of rhabdomyolysis. Regardless of these controversies, the overall prognosis for rhabdomyolysis is favourable when treated with early and aggressive IVF resuscitation, and full recovery of renal function is common. Irrespective of the cause of rhabdomyolysis the mortality rate may still be as high as 8%. This is a comprehensive review of the pathophysiology, diagnosis, complications and treatment options for rhabdomyolysis.

ACE ID genotype affects blood creatine kinase response to eccentric exercise

Unaccustomed exercise may cause muscle breakdown with marked increase in serum creatine kinase (CK) activity. The skeletal muscle renin-angiotensin system (RAS) plays an important role in exercise metabolism and tissue injury. A functional insertion (I)/deletion (D) polymorphism in the angiotensin I-converting enzyme (ACE) gene (rs4646994) has been associated with ACE activity. We hypothesized that ACE ID genotype may contribute to the wide variability in individuals' CK response to a given exercise. Young individuals performed maximal eccentric contractions of the elbow flexor muscles. Pre- and postexercise CK activity was determined. ACE genotype was significantly associated with postexercise CK increase and peak CK activity. Individuals harboring one or more of the I allele had a greater increase and higher peak CK values than individuals with the DD genotype. This response was dose-dependent (mean +/- SE U/L: II, 8,882 +/- 2,362; ID, 4,454 +/- 1,105; DD, 2,937 +/- 753, ANOVA, P = 0.02; P = 0.009 for linear trend). Multivariate stepwise regression analysis, which included age, sex, body mass index, and genotype subtypes, revealed that ACE genotype was the most powerful independent determinant of peak CK activity (adjusted odds ratio 1.3, 95% confidence interval 1.03-1.64, P = 0.02). In conclusion, we indicate a positive association of the ACE ID genotype with CK response to strenuous exercise. We suggest that the II genotype imposes increased risk for developing muscle damage, whereas the DD genotype may have protective effects. These findings support the role of local RAS in the regulation of exertional muscle injury.

Exercise-induced rhabdomyolysis

Rhabdomyolysis is a debilitating condition that promotes muscle breakdown and eventually leads to renal dysfunction if not properly managed. The initial presentation may involve lower-extremity muscles, making the foot and ankle specialist one of the first specialists to recognize and diagnose this condition. Proper management of renal function is the primary concern; however, the underlying muscle breakdown needs to be addressed and the condition managed to prevent future problems. In this article we discuss treatment of a patient with exercise-induced rhabdomyolysis; a rehabilitation regimen is presented whose purpose is to condition muscles in order to prevent recurrence of exercise-induced muscle destruction after an acute event.

Rhabdomyolysis in pontocerebellar hypoplasia type 2 (PCH-2)

Pontocerebellar hypoplasia type 2, an autosomal recessive neurodegeneration with prenatal onset, is characterised by progressive microcephaly and chorea/dystonia and has not previously been associated with muscular involvement. The gene associated with PCH-2 is unknown. An episode of rhabdomyolysis is reported in two non-related children with PCH-2, fatal in one, precipitated by intercurrent disease. Muscle biopsies in two other PCH-2 patients, and in one rhabdomyolysis patient whose biopsy antedated this complication showed areas of myofibrillar disruption or necrosis. Postmortem muscle sampled in another case without neuromuscular symptoms revealed focal necrosis, regenerating small fibres and upregulation of HLA-ABC. Random serum creatine kinase values in six other PCH-2 patients without clinical signs of neuromuscular involvement were increased in four. Collected data provide preliminary evidence of a subclinical myopathy associated with PCH-2.

Severe rhabdomyolysis and acute renal failure secondary to concomitant use of simvastatin, amiodarone, and atazanavir

OBJECTIVE

To report a case of a severe interaction between simvastatin, amiodarone, and atazanavir resulting in rhabdomyolysis and acute renal failure.

BACKGROUND

A 72-year-old white man with underlying human immunodeficiency virus, atrial fibrillation, coronary artery disease, and hyperlipidemia presented with generalized pain, fatigue, and dark orange urine for 3 days. The patient was taking 80 mg simvastatin at bedtime (initiated 27 days earlier); amiodarone at a dose of 400 mg daily for 7 days, then 200 mg daily (initiated 19 days earlier); and 400 mg atazanavir daily (initiated at least 2 years previously). Laboratory evaluation revealed 66,680 U/L creatine kinase, 93 mg/dL blood urea nitrogen, 4.6 mg/dL creatinine, 1579 U/L aspartate aminotransferase, and 738 U/L alanine aminotransferase. Simvastatin, amiodarone, and the patient's human immunodeficiency virus medications were all temporarily discontinued and the patient was given forced alkaline diuresis and started on dialysis. Nine days later the patient's creatine kinase had dropped to 1695 U/L and creatinine was 3.3 mg/dL. The patient was discharged and continued outpatient dialysis for 1 month until his renal function recovered.

DISCUSSION

The risk of rhabdomyolysis is increased in the presence of concomitant drugs that inhibit simvastatin metabolism. Simvastatin is metabolized by CYP3A4. Amiodarone and atazanavir are recognized CYP3A4 inhibitors.

CONCLUSIONS

Pharmacokinetic differences in statins are an important consideration for assessing the risk of potential drug interactions. In patients requiring the concurrent use of statins and CYP3A4 inhibitors, pravastatin, fluvastatin, and rosuvastatin carry the lowest risk of drug interactions; atorvastatin carries moderate risk, whereas simvastatin and lovastatin have the highest risk and should be avoided in patients taking concomitant CYP3A4 inhibitors.

Myopathy associated with anti-signal recognition peptide antibodies: clinical heterogeneity contrasts with stereotyped histopathology

We report three patients with anti-signal recognition particle antibodies who had different presenting clinical pictures, mimicking acute polymyositis, limb-girdle muscular dystrophy, and acute rhabdomyolysis. Muscle biopsies typically showed necrotizing myopathy with little or no inflammation and deposits of membrane attack complex (C5b-9) in endomysial capillaries. The clinical course was severe in two patients and mild in one. The combination of corticosteroid with either an immunosuppressive agent or intravenous immunoglobulins was required to improve the condition of these patients.

New syndromes in mushroom poisoning

Several new mushroom poisoning syndromes have been described since the early 1990s. In these syndromes, the onset of symptoms generally occurs >6 hours after ingestion. Treatment is mainly supportive. The syndrome induced by Amanita smithiana/proxima consists of acute tubulopathy, which appears earlier and does not have the same poor prognosis as the orellanine-induced syndrome. It has been described since 1992 in the US and Canada with A. smithiana; in France, Spain and Italy with A. proxima; and in Japan with A. pseudoporphyria. The responsible toxin is probably 2-amino-4,5-hexadienoic acid. The erythromelalgia syndrome has been described as early as the late 19th century in Japan and South Korea with Clitocybe acromelalga, and since 1996 in France and then Italy with C. amoenolens. Responsible toxins are probably acromelic acids identified in both species. Several cases of massive rhabdomyolysis have been reported since 1993 in France and 2001 in Poland after ingestion of large amounts of an edible and, until then, valuable species called Tricholoma equestre. These cases of rhabdomyolysis are associated with respiratory and cardiac (myocarditis) complications leading to death. Rhabdomyolysis with an apparently different mechanism was described in Taiwan in 2001 with Russula subnigricans. Finally, cases of encephalopathy were observed twice after ingestion of Hapalopilus rutilans in Germany in 1992 and Pleurocybella porrigens in Japan in 2004, where a convulsive encephalopathy outbreak was reported in patients with history of chronic renal failure.

The role of the International Society of Nephrology/Renal Disaster Relief Task Force in the rescue of renal disaster victims

Disasters are a major cause of distress and material as well as corporal damage. Next to direct trauma, the crush syndrome inducing multiorgan problems as a consequence of muscle compression and the release of muscular contents into the bloodstream is the most important cause of death; this is to a large extent related to the induction of severe acute kidney injury, for which dialysis is a life-saving therapy. The practical means (both hardware and personnel) to do so are, however, often lacking in disaster conditions. The Renal Disaster Relief Task Force (RDRTF) offered support for renal problems in the aftermath of several disasters, e.g. the Marmara earthquake (1999) in Turkey, the Bam earthquake (2003) in Iran, and the Kashmir earthquake (2005) in Pakistan. A preconceived intervention plan is followed with adaptations according to local conditions. Material and personnel are dispatched to the disaster areas. These interventions have been life-saving for a substantial number of victims. The current article describes the structure and approach of the RDRTF.

Exertional Rhabdomyolysis and Acute Renal Failure in Marathon Runners

Strenuous exercise, including marathon running, can result in damage to skeletal muscle cells, a process known as exertional rhabdomyolysis. In most cases, this damage is resolved without consequence. However, when the damage is profound, there is a release of muscle proteins into the blood; one of these proteins, myoglobin, in high concentrations and under certain conditions (such as dehydration and heat stress) can precipitate in the kidneys, thereby resulting in acute renal failure. Although the marathon is a gruelling physiological challenge, with races sometimes run in hot and humid weather, acute renal failure is relatively infrequent. From case reports, a high proportion of marathon runners who developed acute renal failure had taken analgesics, had a viral or bacterial infection, or a pre-existing condition. The rare cases of acute renal failure in marathon runners may be a situation of the 'perfect storm' where there are several factors (heat stress, dehydration, latent myopathy, non-steroidal anti-inflammatory or other drug/analgesic use, and viral/bacterial infection) that, in some combination, come together to result in acute renal failure.

[Status asthmaticus with rhabdomyolysis of the respiratory muscles]

A 40-year-old roofer called the medical emergency team because of sudden dyspnea and chest constriction. He was suffering from bronchial asthma that exacerbated probably due to the inhalation of a solvent while at work. Because of status asthmaticus he was intubated immediately after arrival in the hospital and breathing had to be assisted artificially for ten hours. After extubation he complained of chest pain. In view of an elevated creatinkinase of 4368 U/1 this was interpreted as rhabdomyolysis of the respiratory muscles due to the status asthmaticus. As a cause of chest pain and elevation of creatinkinase after severe respiratory work under hypoxic conditions rhabdomyolysis of the involved musculature has to be considered.

Amyloid myopathy presenting with rhabdomyolysis: evidence of complement activation

At age of 57 years, a man experienced an episode of rhabdomyolysis. On that occasion muscle biopsy was not performed, however monoclonal gammopathy of undetermined significance (MGUS) was diagnosed. Further he developed a moderate proximal muscle weakness with CK level persistently elevated (1000-1200U/l). When he came to our observation, at age 67, a muscle biopsy revealed an amyloid myopathy and multiple myeloma was at the same time disclosed. Terminal complement complex C5b9 (membrane attack complex) deposits were found in the vessel walls and muscle fibers surface depicted by amyloid. Our case suggests to keep in mind the possibility that amyloid myopathy may begin as an isolate episode of rhabdomyolysis. The detection of complement complex C5b9 suggests that complement cascade is implicated in the muscular damage of amyloid myopathy.

Statins and myotoxicity: a therapeutic limitation

Hydroxymethylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors represent the most successful class of drugs for the treatment of hypercholesterolaemia and dyslipidaemia implicated in the pathogenesis of coronary heart disease and atherosclerosis. However, the popular profile of statins in terms of efficacy has been maligned by its adverse events. The myotoxicity, ranging from mild myopathy to serious rhabdomyolysis, associated with HMG-CoA reductase inhibitors, during treatment of hypercholesterolaemia is of paramount importance. Rhabdomyolysis is a rare but idiosyncratic muscle wasting disorder of different etiologies. Statin-associated rhabdomyolysis causes skeletal muscle injury by self-perpetuating events leading to fatal irreversible renal damage through a series of biochemical reactions. Preferential distribution and action of statins in liver could be the key to minimise myotoxicity concerns. Hepato-specific distribution of statins is governed by various factors such as physicochemical properties, pharmacokinetic properties and selective transporter-mediated uptake in liver rather in extrahepatic cells. The interactions of statins with concomitant drugs of different classes merit attention for their safety profile. Although pharmacokinetic as well as pharmacodynamic interactions have been implicated in pathophysiology of statin-induced muscle wasting, the underlying mechanism is not clearly understood. Besides, pharmacokinetic and phramcodynamic factors, statin-associated myotoxcity may also implicate pharmacogenomic factors. The pharmacogenomics characterised by CYP polymorphism and other genetic factors is responsible for inter-individual variations to efficacy and tolerability of statins. The pathophysiological mechanisms may include statin-induced differences in cholesterol:phospholipid ratio, isoprenoid levels, small GTP binding proteins and apoptosis. However, the present understanding of pathophysiological mechanisms, does not offer a reliable approach to address the same at preclinical level. Although statin-associated myotoxicity affects compliance, quality of life of patient and discontinuation rate, yet the low incidence of myotoxicty including rhabdomyolysis and less severity of commonly occurring myopathy and myalgia do not raise doubts about the clinical efficacy and tolerability of statins. Medical management of myotoxicity seems to be pivotal for the proper compliance of patients with statin treatment. The appropriate and judicious use of drugs would substantially reduce the likelihood of developing clinically important myopathy.

Recurrent Rhabdomyolysis in a Collegiate Athlete

PURPOSE

Hereditary metabolic disorders can cause rhabdomyolysis in athletes. Team physicians should be aware of the presentation, workup, and management of the most common of these disorders, carnitine palmitoyltransferase (CPT) II deficiency and muscle phosphorylase deficiency.

METHODS

The case of a collegiate athlete with recurrent bouts of rhabdomyolysis is presented, and the diagnostic workup is discussed.

RESULTS

The patient described in this case has CPT II deficiency. The diagnosis and management of CPT II deficiency and muscle phosphorylase deficiency (McArdle's disease) are discussed.

CONCLUSION

Athletes with rhabdomyolysis, in the absence of an obvious cause such as drug toxicity, severe trauma, or excessive exercise, should be evaluated for the presence of a metabolic myopathy.

Using quantitative acid-base analysis in the ICU

The quantitative acid-base 'Strong Ion' calculator is a practical application of quantitative acid-base chemistry, as developed by Peter Stewart and Peter Constable. It quantifies the three independent factors that control acidity, calculates the concentration and charge of unmeasured ions, produces a report based on these calculations and displays a Gamblegram depicting measured ionic species. Used together with the medical history, quantitative acid-base analysis has advantages over traditional approaches.

Rare Case of Rhabdomyolysis with Therapeutic Doses of Phendimetrazine Tartrate

Phendimetrazine tartrate is a newer drug that acts as a central stimulant and indirectly acting sympathomimetic with a host of uses similar to the class amphetamines. Its main use is as an anorectic in the short-term treatment of obesity, although stimulants are no longer indicated for this purpose. This drug appeals to the younger American population for immediate weight loss through decreased appetite and early satiety. The European Union markets have already withdrawn this medication as well as other countries, but phendimetrazine is still used within the United States. Rhabdomyolysis is a potentially life-threatening complication reported with higher doses of amphetamines. We present a case of rhabdomyolysis and myoglobinuria developing in a 23-year-old patient after oral administration of phendimetrazine tartrate for 3 days in suggested therapeutic doses. The medication was taken for short-term treatment of obesity, and patient did not have any predisposing factors to precipitate rhabdomyolysis. Rhabdomyolysis resolved within 5 days. To our knowledge, this is the first reported case of rhabdomyolysis from administration of therapeutic amounts of phendimetrazine tartrate. The purpose of this case report is to create an awareness among physicians about the potentially life-threatening complications associated with phendimetrazine use as an anorectic even in suggested therapeutic doses as was the case in our patient. Additional awareness is needed to educate their patients about the side effects associated with these drugs and to strongly discourage their unsupervised use.

Acute myositis

Two cases of acute myositis characterized by intense muscle pain, weakness, myoglobinuria in one and muscle biopsy showing inflammatory changes in both with good recovery are described. It is reported because of the rarity of this condition.

Pathophysiology and clinical presentations of rhabdomyolysis

Rhabdomyolysis has sparked new interest in recent years. The causes of rhabdomyolysis include drugs and other toxic agents, infections, physical exertion, crush injury, and muscle diseases (dystrophinopathies and metabolic myopathies). Prompt identification of the pathophysiological mechanism is the key to rapid control of the acute episode and to prevention of recurrences. In this update, we discuss the pathophysiological mechanisms and nosology of rhabdomyolysis, as well as diagnostic investigations, with special emphasis on noninvasive methods.

Improving effect of ethyl eicosapentanoate on statin-induced rhabdomyolysis in Eisai hyperbilirubinemic rats

The effect of ethyl eicosapentanoate (EPA-E) on statin-induced rhabdomyolysis was investigated by co-administration of EPA-E and pravastatin (PV), as a typical statin, to Eisai hyperbilirubinemic rats (EHBR). It was confirmed that the plasma PV concentration was not affected by simultaneous administration of EPA-E, and there was no cumulative increase of PV during prolonged co-administration of EPA-E and PV. Muscular degeneration was prominent (incidence 5/5; average grade 3.5 (range 2-4)) in EHBR treated with PV alone at 200 mg/kg/day for 14 days, but co-administration of EPA-E at doses of 100, 300, and 1000 mg/kg/day decreased the average grades to 1.4 (range 0.3-3.0), 0.5 (0.2-1.0), and 0.6 (0.0-1.7), respectively. Creatine phosphokinase (CPK) and myoglobin levels in plasma were well correlated with the grade of skeletal muscle degeneration. Thus, EPA-E appears to reduce the severity of statin-induced rhabdomyolysis.

Severe rhabdomyolysis, acute renal failure and posterior encephalopathy after ???magic mushroom??? abuse

We report the case of a 25-year-old, hepatitis C-infected man, who presented with severe rhabdomyolysis and acute renal failure, and later developed posterior encephalopathy with cortical blindness after the ingestion of magic mushrooms. Conventional respiratory and cardiovascular support including mechanical ventilation, continuous veno-venous hemodialysis and corticosteroids led to improvement and the patient recovered completely over the following months. Magic mushrooms are becoming increasingly fashionable among drug users, as they are believed to be more harmless than other hallucinogenic designer drugs. So far, little is known about their possible severe side effects.