Can taking Repatha (evolocumab) cause muscle loss?

Repatha (Evolocumab) and Muscle Mass: Safety Profile Assessment

Repatha (evolocumab) does not cause muscle loss or muscle-related adverse events, and is actually a good alternative for patients who experience muscle symptoms with statins.

Muscle-Related Safety Profile of Evolocumab

Evolocumab (Repatha) is a PCSK9 inhibitor that significantly reduces LDL cholesterol levels. According to the most recent clinical guidelines and safety data:

• The 2022 ACC Expert Consensus Decision Pathway specifically notes that evolocumab's adverse effects primarily include nasopharyngitis, upper respiratory tract infection, influenza, back pain, and injection site reactions 1

• The FDA label for Repatha indicates that muscle-related adverse events are not a significant concern:

  • In a 52-week controlled trial, myalgia occurred in only 4.0% of Repatha-treated patients compared to 3.0% in the placebo group 2
  • Muscle spasms were reported in just 1.3% of Repatha-treated patients versus 1.2% in placebo-treated patients in pooled 12-week trials 2
  • Importantly, discontinuation due to myalgia was rare, occurring in only 0.3% of Repatha-treated patients versus 0% in placebo-treated patients 2

• The FOURIER trial, which evaluated evolocumab in over 27,500 patients, found no differences in the rates of muscle-related events between evolocumab and placebo groups 1

Advantages for Patients with Muscle Concerns

Evolocumab may actually be beneficial for patients who experience muscle symptoms with statins:

• Unlike statins, which can cause muscle-related side effects in some patients, PCSK9 inhibitors like evolocumab work through a completely different mechanism that does not affect muscle metabolism 3

• The American College of Cardiology notes that PCSK9 inhibitors are particularly useful options for patients who cannot tolerate statins due to muscle symptoms 3

Clinical Considerations

When considering Repatha therapy:

1. Monitor for common side effects: Focus on injection site reactions (5.7%), nasopharyngitis (10.5%), and upper respiratory infections (9.3%) rather than muscle symptoms 2

2. Watch for hypersensitivity reactions: These are more clinically significant concerns with evolocumab than muscle issues 1

3. Recognize the benefit-risk profile: The significant LDL-C reduction (50-65%) provided by evolocumab outweighs the minimal risk of muscle-related adverse events 3

Important Distinctions from Statins

It's important to understand that:

• Statin medications are associated with muscle-related adverse events including myalgia, myopathy, and rarely rhabdomyolysis
• Evolocumab works through the PCSK9 pathway rather than inhibiting HMG-CoA reductase, which is why it doesn't share the muscle-related side effect profile of statins
• Clinical trials have consistently shown that muscle-related events with evolocumab occur at rates similar to placebo 1

In conclusion, there is no evidence that Repatha (evolocumab) causes muscle loss. For patients concerned about muscle symptoms, evolocumab may actually be a preferred option compared to statins when additional LDL-C lowering is required.