Abstract
Differential diagnosis of muscle pain and weakness is extensive, including neurological, vertebral, arthrogenic, vascular, traumatic, immunological, endocrine, genetic and infectious
aetiologies, as well as medication or toxin-related causes. Muscles are highly sensitive to a large number of drugs, especially with high doses. Although many drug classes can cause toxic
myopathy, a significant number of cases are caused by lipid-lowering drugs, long-term use of corticosteroids, and, most often, alcohol misuse. Some drug interactions, e.g. those that are
metabolised via the enzyme CYP3A4, can increase the serum levels of the drugs and drug-induced toxicity. A careful history of patientʼs drug and alcohol consumption is therefore vital.
Clinical symptoms depend on the drug, dosage and patientʼs sensitivity. They can vary from asymptomatic increase in serum levels of creatine kinase, mild myalgia and cramps to muscle
weakness, rhabdomyolysis, kidney failure and even death. The pathogenesis is often only partially known and multifactorial. Toxic myopathy is often reversible once the drug is discontinued,
alternative drug therapy is started or a different dosage regimen is chosen. Complications such as acute kidney failure must be avoided, and analgesic therapy may be indicated.
Key words
muscle - toxic myopathy - myopathy - myalgia - adverse effect
