Brief Answer: Usually start after at least a year Detailed Answer: HI, thanks for using healthcare magic In most cases symptoms related to myopathy (muscle weakness) and myalgia (muscle pain) start by at least a year after therapy has been initiated. It is unusual for it to start after 3 years, though persons react differently to medication. It is related to the dose of the medication and the type of statin used. Some statins are more likely to cause muscle pain compared to others. Lipitor and zocor are associated with an higher incidence of myopathy and myalgia compared to lescol. Your doctor will consider checking the levels of CPK (creatinine phosphokinase). This is normally elevated in muscle injury. Other possible causes must be ruled out such as excess physical activity , hypothyroidism. In general the drug is stopped to see if the symptoms resolve, this can take up to a month. When the symptoms stop, the options would be to use another drug , use a lower dose of the same drug or use a non statin to lower the cholesterol. Your doctor will discuss these options with you. I hope this helps,, feel free to ask any other questions

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