From the FDA Drug Label
Pitavastatin tablets may cause myopathy (muscle pain, tenderness, or weakness associated with elevated creatine kinase [CK]) and rhabdomyolysis. Dosages of pitavastatin tablets greater than 4 mg once daily were associated with an increased risk for severe myopathy in premarketing clinical studies.
The incidence of myopathy is not explicitly quantified in the provided drug label. However, it is mentioned that dosages greater than 4 mg once daily were associated with an increased risk for severe myopathy in premarketing clinical studies 1.
- Risk factors for myopathy include:
- Age 65 years or greater
- Uncontrolled hypothyroidism
- Renal impairment
- Concomitant use of certain drugs
- Higher pitavastatin tablets dosage It is recommended to discontinue pitavastatin tablets if markedly elevated CK levels occur or if myopathy is either diagnosed or suspected.
From the Research
Pitavastatin has a relatively low incidence of myopathy compared to other statins, with reported rates of approximately 1-5% for muscle-related adverse effects, as supported by the most recent study 2. The risk of serious myopathy (muscle pain with significant CK elevation) is even lower at less than 0.1%. Pitavastatin's favorable myopathy profile is likely due to its minimal metabolism through the cytochrome P450 system, specifically CYP2C9 and not CYP3A4, which reduces drug interactions that can increase statin concentration and myopathy risk, as discussed in 3. Additionally, pitavastatin has limited penetration into skeletal muscle tissue. Some key points to consider when evaluating the risk of pitavastatin-induced myopathy include:
- Risk factors for developing pitavastatin-associated myopathy include advanced age, female gender, small body frame, renal or hepatic impairment, hypothyroidism, vitamin D deficiency, and concomitant use of medications like fibrates, cyclosporine, or certain antibiotics, as mentioned in 4.
- If patients experience muscle symptoms while taking pitavastatin, they should be evaluated with CK levels and the medication may need to be temporarily discontinued or the dose reduced.
- For patients with a history of statin-induced myopathy, pitavastatin may be considered as an alternative statin due to its lower myopathy risk profile, as suggested by 5 and 6. It is essential to weigh the benefits and risks of pitavastatin therapy, considering its efficacy in reducing cardiovascular events and mortality, as well as its safety profile, including the low risk of myopathy, as highlighted in 2.