From the Guidelines
Micronized fenofibrate has a lower risk of interaction with atorvastatin compared to other fibrates like gemfibrozil. When combining these medications, micronized fenofibrate (such as Tricor) at doses of 48-145 mg daily is preferred when used with atorvastatin (typically 10-80 mg daily) 1. This combination therapy should be monitored with liver function tests and creatine kinase at baseline, after 6-12 weeks, and periodically thereafter. Patients should be advised to report muscle pain, tenderness, or weakness immediately. The reduced interaction risk occurs because micronized fenofibrate minimally inhibits CYP450 enzymes that metabolize statins, unlike gemfibrozil which significantly inhibits statin metabolism through glucuronidation pathways 1. This pharmacokinetic difference results in less statin accumulation and lower risk of myopathy when micronized fenofibrate is used. However, some increased risk still exists compared to statin monotherapy, so the combination should be reserved for patients with significant mixed dyslipidemia who haven't achieved targets with single-agent therapy. Key considerations for the use of this combination include:
- Monitoring for signs of myopathy, such as muscle pain or weakness
- Regular assessment of liver function and creatine kinase levels
- Patient education on the potential risks and benefits of combination therapy
- Selection of patients with significant mixed dyslipidemia who have not responded to single-agent therapy. It is also important to note that the combination of high-dose statin plus fibrate can increase the risk for severe myopathy, and statin doses should be kept relatively low with this combination 1.
From the FDA Drug Label
Fibrates (other than Gemfibrozil) Clinical Impact:Fibrates may cause myopathy when given alone. The risk of myopathy and rhabdomyolysis is increased with concomitant use of fibrates with atorvastatin calcium Intervention:Consider if the benefit of using fibrates concomitantly with atorvastatin calcium outweighs the increased risk of myopathy and rhabdomyolysis. If concomitant use is decided, monitor patients for signs and symptoms of myopathy particularly during initiation of therapy and during upward dose titration of either drug
The interaction between micronized fibrates and atorvastatin is not explicitly different from the interaction between other fibrates and atorvastatin in the provided drug labels.
- The risk of myopathy and rhabdomyolysis is increased with concomitant use of fibrates (including micronized fibrates) with atorvastatin.
- It is recommended to consider the benefit of using fibrates concomitantly with atorvastatin and weigh it against the increased risk of myopathy and rhabdomyolysis.
- If concomitant use is decided, patients should be monitored for signs and symptoms of myopathy during initiation of therapy and upward dose titration of either drug 2 2 2.