Localized Rhabdomyolysis After Exertion in a Cardiac Transplant Recipient on Statin Therapy

Statin-associated focal myositis

Myositis is an infrequent side effect of statin therapy, usually presenting as diffuse myositis with muscle weakness and cramping involving multiple body parts. We report a case of focal myositis of a hip muscle diagnosed on magnetic resonance imaging, as the underlying pathology was suspected to be related to an orthopaedic disease due to isolated hip symptoms, and which was finally attributed to statin intake. Awareness to this rare cause of musculoskeletal symptoms is indicated in case a patient presents with probable orthopaedic disease and is on statin therapy.

Fluvastatin as co-medication in heart transplant recipients with elevated creatine-kinase

BACKGROUND

Statins reduce the risk for transplant vasculopathy and mortality among heart transplant recipients. Interactions between commonly used statins (ie, simvastatin, atorvastatin) and immunosuppressant drugs lead to side effects or withdrawal of statin therapy. Fluvastatin shows fewer interactions with the immunosuppressant agents because it is not metabolized via the cytochrome P-450 3A4 pathway like most immunosuppressants, steroids, or other statins. This study investigated the impact of a switch from other statins to fluvastatin in heart transplant recipients who revealed elevated creatine-kinase levels.

METHODS

A total of 23 heart transplant patients with elevated creatine-kinase levels were included in this study. Statins were replaced with an equal dosage of fluvastatin. We measured on the day of replacement as well as there after at 3, 6, 9, and 12 months creatine-kinase, lipid status, ALT, AST, and creatinine levels.

RESULTS

After 6 months creatine-kinase showed a significant reduction of 25% (P < .05) and after 9 months of 38% (P < .05). The HDL-cholesterol levels were significantly reduced at 6 months (8%; P < .05) and 9 months (23%; P < .05). At 3 months, triglyceride levels were significantly elevated (18%; P < .05). No differences were observed in ALT, AST, creatinine, total, and LDL-cholesterol at any time.

CONCLUSION

A conversion from commonly used statins to fluvastatin in heart transplant patients with elevated creatine-kinase was safe, leading to a significant reduction in creatine-kinase levels. Except for an initial raise in triglycerides and a lowering of HDL-cholesterol, no changes in lipid status were seen. This conversion might help to maintain lipid-lowering therapy in transplant recipients who show side effects using conventional statins.

Asymptomatic statin-induced rhabdomyolysis after long-term therapy with the hydrophilic drug pravastatin

CASE SUMMARY

A male patient aged 73 years, 165 cm in height, and weighing 78 kg presented to the emergency department with dsypnea. He had undergone heart transplantation 7 years earlier and been receiving daily pravastatin therapy for >3 years without complaining of any symptoms. A physical examination of the patient at admission was unremarkable, except for dyspnea. However, laboratory testing revealed that his serum creative kinase (CK) concentration was substantially above the reference range. Pravastatin was immediately discontinued, and the patient was admitted to the intensive care unit for treatment. CK values declined after 3 days, and they returned to within reference range after 3 weeks. The patient was diagnosed with acute rhabdomyolysis; a score of 6 on the Naranjo adverse drug reaction probability scale indicated that pravastatin was the probable cause.

DISCUSSION

The hydrophilic statin pravastatin is frequently recommended for patients who have undergone heart transplantation due to its favorable tolerability profile. Unlike lipophilic statins, hydrophilic statins such as pravastatin are not metabolized in the liver via the cytochrome P450 system and have little potential for adverse events through interaction with drugs metabolized via this pathway. Based on a search of relevant literature, this report appears to be the first to describe a case of asymptomatic rhabdomyolysis occurring in a patient receiving long-term daily therapy with pravastatin after undergoing heart transplantation and who had no muscular symptoms or history of intense physical exertion. The occurrence of acute statin-induced rhabdomyolysis in this case suggests that even hydrophilic statins may have the potential to damage myocytes.

CONCLUSIONS

The hydrophilic statin pravastatin appears to have caused asymptomatic rhabdomyolysis, in the absence of physical exertion, in a patient who had undergone heart transplantation and had been receiving the drug for >3 years. Statin therapy should be initiated at the lowest effective dose, especially in patients who have undergone heart transplantation, and should be followed by close monitoring.