Embedded Files
Adverse effects
Adverse effects
Statin myopathy
Statin myopathy
How common is statin myopathy?
How common is statin myopathy?
5-10% of patients on statins experience statin-induced myopathy.
When does it present?
When does it present?
It usually develops around 6 months after starting statins.
How does it present?
How does it present?
- Features include symptoms such as: muscle pain, stiffness, muscle weakness, and cramping, with or without a raised serum creatine kinase - a product of muscle breakdown.
- Severity can range from:
- Asymptomatic: No symptoms + slight increase in serum CK
- Myalgia: symptoms + normal CK
- Myositis: symptoms + CK <10 x upper limit of normal
- Rhabdomyolysis: CK >10 upper limit of normal (with or without symptoms).
Why do patients get statin myopathy?
Why do patients get statin myopathy?
The mechanism behind statin-induced myopathy is unknown but is thought may to be due to the reduced production of mevalonic acid (produced by HMG-CoA reductase) which is a precursor to compounds which are important in maintaining the integrity of muscle fibres.
How should it be managed?
How should it be managed?
Measure CK urgently if a patient reports muscle pain and stop the drug whilst this is investigated.
Patients with myalgia or myositis can continue the statin but may need reduced dose or changing to another statin.
Patients with rhabdomyolysis should completely discontinue the statin as this can lead to renal failure.
Hepatotoxicity
Hepatotoxicity
Statins rarely but can cause hepatotoxicity. It is normally reversible with cessation of the statin.
When to measure LFTs:
When to measure LFTs:
- after 3 months of treatment
- after any further dose increases
- at 1 year after commencing treatment
Do not repeat again unless indicated.
Interpreting LFTs:
Interpreting LFTs:
- A rise in transaminases <3 x upper limit of normal - Common in first 3 months. Do not stop statin.
- A rise in transaminases >3 x upper limit of normal - Stop the statin temporarily before re-challenging or reduce the dose with closer monitoring.
Report abuse