Statin myopathy

Statins

One of the most feared side effects of statins is muscle tissue damage. The pathophysiological mechanism of this damage is not entirely clear, and it is thought to be:

• sarcolemma instability resulting from a decrease in cholesterol (cholesterol is an important building block of sarcolemma);
• mitochondrial damage;
• direct myotoxicity.

Muscle damage can be classified into 3 groups:

1. myalgia - muscle weakness, stiffness, pain, or cramping at rest or on exertion; creatine kinase (CK) elevation does not occur;
2. myositis - CK elevation with/without muscle symptoms;
3. rhabdomyolysis - muscle symptoms with CK elevation 10 times above the upper limit of the normal range.

The risk of statin myopathy increases when statins are combined with drugs that increase the plasma concentration of statins. These are drugs that, like statins, are metabolized by cytochrome P450 complexes (simvastatin, atorvastatin, lovastatin, rosuvastatin - cytochrome cyp3A4; fluvastatin - cyp2C9, pravastatin is not metabolized).

If statin myopathy is suspected, it is necessary to examine the patient's thyroid function (hypothyroidism) and alcohol abuse. Laboratory determination of CK level is necessary and statin should be discontinued for a minimum of 6 weeks.

References

Related articles

• Myopathy
• Statins

Used literature

1. BEDNAŘÍK, Josef. Toxické a lékové myopatie. Neurológia pre praxi [online]. 2004, roč. -, vol. 3, s. 147, dostupné také z <http://www.solen.sk/index.php?page=pdf_view&pdf_id=901&magazine_id=3>. ISSN 1335-9592. 
2. ↑ Skočit nahoru k:a b ŠTEFAN, Alušík. Nežádoucí účinky statinů – staří známí i noví hříšníci. Medical Tribune. 2011, roč. -, vol. 21, s. -, ISSN 1214-8911. 
3. ↑ GOLÁŇ, Lubor. Chyby a úskalí terapie statiny. Interní medicína pro praktické lékaře [online]. 2004, roč. -, vol. 1, s. 31-32, dostupné také z <http://www.medicinapropraxi.cz/pdfs/med/2004/01/08.pdf>. 
4. ↑ DOC. MUDR. VLADIMÍR SOŠKA, CSC,. Statiny a jejich lékové interakce [online]. ©2013. [cit. 2015-07-03]. <https://www.tribune.cz/clanek/29871-statiny-a-jejich-lekove-interakce>.