statins 類的藥，在老人併腎功能不佳的患者，使用上要特別小心。
Enhanced susceptibility to statin-associated myopathy occurs in patients with acute or chronic renal failure, obstructive liver disease, and hypothyroidism
Pravastatin and fluvastatin appear to have less intrinsic muscle toxicity.
Chronic kidney disease - Chronic kidney disease presents an additional challenge for the selection of a statin. Atorvastatin and fluvastatin do not require dose adjustment and are the statins of choice in patients with severe renal impairment [123,124]. Dose adjustment is warranted with other statins in patients with severe kidney disease (CrCl less than 30 mL/min). If statins other than atorvastatin or fluvastatin are used, pravastatin may be safer than other statins. As an example, in a subset analysis of 1711 participants with chronic kidney disease (creatinine clearance ≤75 mL/min) from the CARE trial, treatment with pravastatin for a median of 58.9 months significantly improved outcomes compared with placebo without an increase in side effects [125].
CYP3A4 drugs - Drugs and substances that inhibit cytochrome P450 3A4 (CYP3A4) (table 1) can increase the risk of statin myopathy due to lovastatin, simvastatin, and to a lesser extent atorvastatin [53]. These include cyclosporine [55-59], macrolide antibiotics (eg, erythromycin) [60], systemic-azole antifungals [61], and HIV/HCV protease inhibitors including ritonavir-boosted regimens (table 1) [55,62,63]. Drugs that do not inhibit CYP3A4 but are competitive CYP3A4 substrates may also have myopathic interactions with statins, as has been reported with myotoxicity with simvastatin and colchicine and elevated concentrations of simvastatin observed when taken with amlodipine [64,65].
Calcium channel blockers - The nondihydropyridine calcium channel blockers diltiazem and verapamil are moderate inhibitors of CYP3A4 metabolism. Manufacturer data indicate that, at a simvastatin dose of 20 to 80 mg/day, there is a 0.6 percent incidence of myopathy in patients also treated with verapamil (a value 10 times higher than seen in patients taking simvastatin without a calcium channel blocker) [12]. The risk is also increased when simvastatin is taken with amlodipine, which is metabolized by CYP3A4 [43,66].
