Severe creatine kinase increase during quetiapine and mirtazapine treatment

In the literature, there have been several publications reporting creatine kinase (CK) increases associated with the use of atypical antipsychotic drugs. In this letter, I would like to present a case in which there was a massive increase in serum CK levels together with relatively modest increases in serum CK myoglobin-band (CK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels during quetiapine and mirtazapine treatment, without the presence of neuroleptic malignant syndrome (NMS).