OBJECTIVE To analyse the clinical characteristics of serum creatine kinase (CK) elevation with myalgia and rhabdomyolysis induced by anti-thyroid drug (ATD), and to provide evidence and reference for clinical practice.

METHODS A computerised search of CNKI, Wanfang, VIP, CBM, PubMed and Embase databases was conducted with a cut-off date of April 2024 to include Chinese and English literature on CK elevation with myalgia or rhabdomyolysis induced by ATD.

RESULTS A total of 1751 literature articles were searched, and 39 articles with a total of 52 adverse drug reactions(ADRs) were finally included, with 50 cases of elevated serum CK and 49 cases complaining of myalgia; 7 cases progressed to rhabdomyolysis, including 1 case with concomitant acute kidney injury. Fifty-two patients were involved, mostly from Asian populations (80.8%), 73.1% female, with a median age of 26.0 years (20.0−33.8 years) and 17.3% children under 18 years of age. The time of onset ranged from 7 to 122 d after treatment with ATD, with a median of 30 d (26.3−56.3 d); dispositions included ATD dose reduction, discontinuation, substitution with other ATD, or addition of levothyroxine; myalgia symptoms resolved within 1 to 122 d, with a median of 12 d (2.5−21.0 d); and the median time to return to normal serum CK levels was 24.5 d (14.0−43.8 d). Ten patients had a recurrence of elevated serum CK with myalgia during subsequent treatment.

CONCLUSION to ATD-induced elevated serum CK with myalgia is a new and under-recognised ADR that healthcare professionals should be more aware of and diagnose and treat early to prevent progression to rhabdomyolysis and acute kidney injury, etc. It is dose-dependent and may be more susceptible in Asian populations. Monthly monitoring of serum CK levels is recommended within 2 months of initial treatment or dose increase of ATD, especially in patients complaining of muscle cramps and myalgia.