Fig. 1-2.

Recommended approaches to adverse events (myopathy) during statin administration

• Myopathy is categorized in the A, B, C, or D groups as shown in the chart according to SAMS and CK level. CK levels may be increased as a result of vigorous exercise and intramuscular injections, which can persist for several days. Thus, when serum CK level is found to be elevated, there is a need to confirm whether the patient experienced either of the above prior to the blood test. In such cases, it is advisable to have the patient remain in a rested state as much as possible for several days and repeat the blood test. Other risk factors associated with myopathy onset include: Being an elderly female, short stature, Asian descent, renal dysfunction, hypothyroidism, excessive alcohol consumption, and surgery. Concomitant drugs that require particular attention include: azure-based anti-fungaldrugs that are antagonists to the drug metabolism system, macrolide antibiotics, protease inhibitors (anti-viral agents), verapamil, diltiazem, amiodarone, warfarin, and cyclosporine (ref 33).

• Proceed according to the relevant flowchart. See the text of the current Guide for details regarding the specific ways of handling each category. As a general rule, the follow-up period for categories B and C are 2–4 weeks and 4–6 weeks, respectively, but following-up on patient progress more frequently may be appropriate.