Creatine drug interactions

HMG Co-A reductase inhibitors A 58-year-old man who was taking simvastatin was given itraconazole for onychomycosis, and the simvastatin was replaced by pravastatin to prevent drug interactions [18 ]. He ran out of pravastatin and started to take simvastatin again. He developed myalgia and muscle weakness after 1 week, with a greatly raised serum creatine kinase activity, and then severe rhabdomyolysis. 

Drug-drug interactions Colchicine Rhabdomyolysis occurred in a 48-year-old African-American man with hypertension and chronic gout, who was taking colchicine 0.6 mg/day and who took clarithromycin 500 mg bd for 3 days for a community-acquired pneumonia [130" ]. The serum aminotransferases rose and the serum creatine kinase activity was 22 996 U/1 the urine contained myoglobin. Withdrawal of colchicine and clarithromycin resulted in clinical and biochemical resolution. 

Creatine kinase activity should be measured in patients receiving potentially interacting drug combinations. In all patients, CK should be measured at baseline. If muscle pain, tenderness, or weakness appears, CK should be measured immediately and the drug discontinued if activity is elevated significantly over baseline. The myopathy usually reverses promptly upon cessation of therapy. If the association is unclear, the patient can be rechallenged under close surveillance. Myopathy in the absence of elevated CK has been reported. Rarely, hypersensitivity syndromes have been reported that include a lupus-like disorder and peripheral neuropathy. 

Rhabdomyolysis is a problem with several lipid-lowering drugs (SEDA-13, 1325 SEDA-13, 1328 SEDA-13, 1330 SEDA-19, 409), especially when they are used in combination (37). In individuals with pre-existing renal insufficiency this can lead to an earlier need for chronic dialysis (38). All statins can cause myopathy and rhabdomyolysis, but not all statins are alike. For example, the evidence to date, based on almost 2 decades of experience, points to an extremely low risk of myopathy and rhabdomyolysis with lovastatin, and lovastatin 20 mg tablets are being considered for non-prescription availability in several countries (39). Furthermore, muscle adverse effects do not necessarily occur after a change from one statin to another (40). Interactions between various hypolipidemic drugs and other drugs also sometimes cause rhabdomyolysis (SEDA-18, 426). For instance, itraconazole markedly increases plasma concentrations of lovastatin, and in one subject plasma creatine kinase was increased 10-fold within 24 hours of administration of this combination (41). 

According to the Physician s Desk Reference (PDR) for Nutritional Supplements, there are no known adverse interactions between creatine monohydrate supplements and prescription drugs, herbs, and/or other dietary supplements. However, the effects of creatine may be decreased or altered by the use of other drugs or supplements, so anyone considering taking the supplement should consult a physician first. 

SEDA-19, 409), especially when they are used in combination (26). In individuals with pre-existing renal insufficiency this can lead to an earlier need for chronic dialysis (27). Interactions between various hypolipidemic drugs and other drugs also sometimes cause rhabdomyo-lysis (SEDA-18,426). For instance, itraconazole markedly increases plasma concentrations of lovastatin, and in one subject plasma creatine kinase was increased 10-fold within 24 hours of administration of this combination (28). 

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