Rhabdomyolysis with atorvastatin and fusidic acid

Rhabdomyolysis after co-administration of a statin and fusidic acid: an analysis of the literature and of the WHO database of adverse drug reactions

Following a severe case of rhabdomyolysis in our University Hospital after a co-administration of atorvastatin and fusidic acid, we describe this interaction as this combination is not clearly contraindicated in some countries, particularly for long-term treatment by fusidic acid. All cases of rhabdomyolysis during a co-administration of a statin and fusidic acid were identified in the literature and in the World and Health Organization database, VigiBase^® . In the literature, 29 cases of rhabdomyolysis were identified; mean age was 66 years, median duration of co-administration before rhabdomyolysis occurrence was 21 days, 28% of cases were fatal. In the VigiBase^® , 182 cases were retrieved; mean age was 68 years, median duration of co-administration before rhabdomyolysis was 31 days and 24% of cases were fatal. Owing to the high fatality associated with this co-administration and the long duration of treatment before rhabdomyolysis occurrence, fusidic acid should be used if there is no appropriate alternative, as long as statin therapy is interrupted for the duration of fusidic acid therapy, and perhaps a week longer. Rarely will interruption of this sort have adverse consequences for the patient.

Muscle Damage Due to Fusidic Acid-Statin Interaction: Review of 75 Cases From the French Pharmacovigilance Database and Literature Reports

BACKGROUND/AREA OF UNCERTAINTY

Statins, which reduce cardiovascular risk in both primary and secondary prevention, are one of the most widely prescribed therapeutic classes in the world. Usually well-tolerated, statin-associated muscle symptoms are a well-known adverse effect. Fusidic acid (FA) is a bacteriostatic antibiotic of interest in the treatment of methicillin-resistant Staphylococcus aureus infections. Cases of rhabdomyolysis, sometimes fatal, have been reported after coprescription of FA and a statin.

DATA SOURCES/AREA OF UNCERTAINTY

We studied 75 cases of muscle damage related to interaction between FA and a statin reported in the French national pharmacovigilance database (43 cases) and from a literature review (32 cases).

RESULTS

Cases were mostly men (72.5%), often overweight (mean body mass index: 29.4). The most commonly reported statins were atorvastatin (60%), simvastatin (22.7%), and rosuvastatin (8.0%). Muscle disorders appeared on average 30 days after initiation of FA. Symptoms were muscle weakness (82%), dark urine (71%), and myalgia (61%). Mean creatine kinase level at diagnosis was 43,890 UI/mL, and acute renal injury occurred more than half of the cases. Outcome was fatal in 22% of cases and 28% kept sequelae at the end of the follow-up (54 days).

CONCLUSIONS

Muscle damage induced by interaction between FA and statin is a potentially life-threatening complication, leading to contraindication of this association in France. This is to be reminded especially because FA is about to get FDA approval and should soon be available in the United States.

High-Intensity Atorvastatin-Induced Rhabdomyolysis in an Elderly Patient With NSTEMI: A Case Report and Review of the Literature

A 91-year-old male was admitted to the hospital for worsening muscle weakness, muscle pain, and unexplained soreness for the past 10 days. Four months prior to his admission, the patient had experienced a myocardial infarction and was initiated on atorvastatin 80 mg daily. Although the provider had instructed the patient to decrease the atorvastatin dose to 40 mg daily 3 months prior to admission, the patient did not adhere to the lower dose regimen until 10 days prior to hospitalization. Upon admission, the patient presented with muscle weakness and pain, a serum creatinine phosphokinase of 18 723 U/L, and a serum creatinine of 1.6 mg/dL. The atorvastatin dose was held and the patient was treated with intravenous fluids. The 2013 American College of Cardiology and American Heart Association Blood Cholesterol Practice Guidelines recommend the use of moderate-intensity statins in patients older than 75 years to prevent myopathy. However, in clinical practice, aggressive statin therapy is often prescribed for significant coronary disease. Prescribing high-intensity statins for patients with advanced age, such as this case, may increase the risk of rhabdomyolysis and other complications. This case report suggests that providers should avoid or be cautious with initiating high-intensity atorvastatin in elderly patients over 75 years to minimize the risk of rhabdomyolysis.

Rhabdomyolysis Induced by Coadministration of Fusidic Acid and Atorvastatin: A Case Report and Comprehensive Review of the Literature

Statins are among the most widely prescribed medications worldwide. Acute rhabdomyolysis constitutes a potentially life-threatening side effect regardless of whether statins are administered alone or in combination. The potentially fatal combination of a statin and fusidic acid has been well described in the literature. Acute renal failure can be a direct consequence of this drug-drug interaction. We present a case of a 79-year-old woman who presented to our Emergency Department with a one-week history of limb weakness, myalgia, and inability to stand and walk. The patient had been given fusidic acid to treat Methicillin-Sensitive Staphylococcus Aureus (MSSA) positive dermatitis in the 3 weeks prior to admission, while she continued to take her complete therapeutic regimen, which included atorvastatin. Thus, she developed rhabdomyolysis due to the interaction between fusidic acid and atorvastatin. Herein, we report a life-threatening complication of coadministration of fusidic acid and a statin, which is preventable and predictable. The exact mechanism of the interaction is not fully understood, but coadministration of these two medications must be avoided in clinical practice.

Fusidic Acid Inhibits Hepatic Transporters and Metabolic Enzymes: Potential Cause of Clinical Drug-Drug Interaction Observed with Statin Coadministration

Fusidic acid (FA), which was approved in the 1960s in many European and Asian countries, has gained renewed interest due to its continued effectiveness against methicillin-resistant Staphylococcus aureus As rhabdomyolysis has been reported upon coadministration of FA with statins, we aimed to elucidate the underlying molecular mechanisms that contribute to FA-statin drug-drug interactions. Because of the association between rhabdomyolysis and increased exposure to statins, we investigated if cytochrome P450 (CYP) enzymes and transporters involved in the disposition of various statins are inhibited by FA. FA was found to inhibit BCRP and OATP1B1 but not P-gp. In overexpressing cell systems, FA inhibited BCRP-mediated efflux (50% inhibitory concentration [IC50], ∼50 to 110 μM) and OATP1B1-mediated uptake (IC50, ∼4 to 35 μM) of statins at clinically relevant concentrations achievable in the intestine and liver (based on a 550-mg oral dose of FA, the expected maximum theoretical gastrointestinal concentration is ∼4 mM, and the maximum total or unbound concentration in the inlet to the liver was reported to be up to 223 μM or 11 μM, respectively, upon multiple dosing). Similarly, FA inhibited metabolism of statins in human liver microsomes (IC50, ∼17 to 195 μM). These data suggest that FA inhibits at least 3 major dispositional pathways (BCRP, OATP1B1, and CYP3A) and thus affects the clearance of several statins. We confirmed that FA is eliminated via phase 1 metabolism (primarily via CYP3A); however, there is also some phase 2 metabolism (mediated primarily by UGT1A1). Taken together, these data provide evidence for molecular mechanisms that may explain the occurrence of rhabdomyolysis when FA is administered with statins.

The safety record of fusidic acid in non-US markets: a focus on skin infections

Fusidic acid has been in clinical use outside the United States (US) since 1962 for skin infections, including methicillin-resistant Staphylococcus aureus (MRSA). Non-US labeling reflects safety concerns related to gastrointestinal, allergic, hematologic, and neurologic adverse events. We sought to survey available safety data on fusidic acid through the review of published global literature between 1962 and 2007 that contained data on oral fusidic acid safety and a centralized database (VigiBase) of spontaneous safety reports. Overall, the data were concordant with current product labeling, and no serious adverse events, such as death, hospitalization, or hepatotoxicity, were convincingly linked to fusidic acid monotherapy in skin infection patients. Other indications for fusidic acid use were also common, including osteomyelitis with similar reporting of labeled safety characteristics. Study quality was highly varied with limited structure to safety data collection methodology. Significant concerns for recall bias are present, yet these data remain informative in providing signals that require attention in the design and conduct of adequate and well-controlled clinical studies of fusidic acid for potential registration in the United States.

Severe statin-induced rhabdomyolysis mimicking Guillain-Barré syndrome in four patients with diabetes mellitus treated with fusidic acid

BACKGROUND

An interaction between fusidic acid and HMG coenzyme A reductase inhibitors (statins), resulting in rhabdomyolysis, has been described. Pain and mild weakness are common presenting symptoms.

CASE REPORT

We report four patients with Type 2 diabetes prescribed long-term statin treatment who, following treatment with fusidic acid, presented atypically with painless, severe flaccid paralysis suggestive of Guillain-Barré syndrome. This, together with nerve conduction studies consistent with Guillain-Barré syndrome, resulted in the delayed recognition of rhabdomyolysis in these cases.

CONCLUSIONS

The addition of fusidic acid can precipitate rhabdomyolysis in patients with diabetes already taking a statin. This can present with rapidly progressive weakness resembling Guillain-Barré syndrome. We recommend that creatine kinase is checked in patients with diabetes on statin therapy who present with profound weakness and routinely in those commenced on prolonged courses of fusidic acid.

Rhabdomyolysis caused by an interaction of simvastatin and fusidic acid

A case of severe rhabdomyolysis caused by an interaction between fusidic acid and simvastatin is described. Fusidic acid significantly reduces the excretion of simvastatin resulting in increased plasma levels thereby increasing the side effect profile. Simvastatin treatment should be temporarily withheld during treatment with fusidic acid.