Risk factors for rhabdomyolysis with simvastatin and atorvastatin.
OBJECTIVE
To assess the frequency of risk factors for rhabdomyolysis with simvastatin and atorvastatin in cases reported to the Australian Adverse Drug Reactions Advisory Committee (ADRAC).


METHODS
Reports meeting the definition of rhabdomyolysis were reviewed for risk factors including age > or = 70 years, dose > or = 40 mg, hepatic dysfunction, diabetes mellitus, hyperkalaemia, hypothyroidism and the use of concomitant interacting medications.


RESULTS
Only one report associated with simvastatin and five reports associated with atorvastatin did not list any risk factors for rhabdomyolysis. Interacting medicines featured in 77% of reports of rhabdomyolysis associated with simvastatin and 44% of reports associated with atorvastatin. A comparison of the age profile for reports of atorvastatin- and simvastatin-associated rhabdomyolysis with that for all adverse drug reaction reports received, and for all reports of muscle disorders, suggested a trend towards an increasing risk of rhabdomyolysis with increasing age with simvastatin but not with atorvastatin. Similarly, comparing prescribed tablet strengths from Pharmaceutical Benefits Scheme data with the HMG-CoA reductase inhibitor ('statin') doses in reports of rhabdomyolysis suggested a dose-related risk with simvastatin, but a less increased risk with high-dose atorvastatin.


CONCLUSIONS
Risk factors for rhabdomyolysis featured in nearly all of the reports of statin-associated rhabdomyolysis and the majority of reports listed multiple risk factors, although dependence on risk factors appeared to be stronger with simvastatin than atorvastatin. The multiplication of risk factors in patients taking simvastatin and atorvastatin should be minimised.
Ronaldson
Kathlyn J
KJ
Department of Epidemiology and Preventive Medicine, NHMRC Centre of Clinical Research Excellence in Therapeutics, Monash University, The Alfred, Melbourne, Victoria, Australia. Kathlyn.Ronaldson@med.monash.edu.au
O'Shea
Justine M
JM
Boyd
Ian W
IW
D000069059:Atorvastatin; D001315:Australia / Q000453:epidemiology; D006538:Heptanoic Acids / Q000009:adverse effects*; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000009:adverse effects*; D011758:Pyrroles / Q000009:adverse effects*; D012206:Rhabdomyolysis / Q000139:chemically induced* / Q000453:epidemiology; D012307:Risk Factors; D019821:Simvastatin / Q000009:adverse effects*
D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D011758:Pyrroles; D000069059:Atorvastatin; D019821:Simvastatin