Endocrine Abstracts

Case history: 20 year old male with Asperger's and OCD was admitted as a psychiatric inpatient and started on aripiprazole and subsequently quetiapine. His symptoms were well controlled, however his creatine kinase rose significantly over the subsequent 3 months. He had no symptoms of neuroleptic malignant syndrome and despite other parameters being investigated, no other causes were found. For this reason, advice from endocrinologists was sought for advice on management of a case of massive asymptomatic creatine kinase elevation (MACKE).

Investigations: Creatine kinase rose from a 2530 u/l baseline while on aripiprazole, to 6293 u/l upon changing to quetiapine. His GFR and U&Es were consistently stable with no symptoms of neuroleptic malignant syndrome. His TSH was mildly elevated, however even after normalising with treatment, his creatine kinase remained elevated.

Results and treatment: Discussions were had with the Psychiatry and Endocrinology consultants. It was decided to cautiously continue the antipsychotics in order to manage his debilitating mental health symptoms. His U&Es and symptoms such as muscle rigidity and high temps were monitored for. The patient was initially on low-dose sertraline, which was stopped when the high creatine kinase was noted. After a dose reduction of quetiapine, his creatine kinase dropped to 2393 u/l. It was decided that this range was acceptable and he could continue on the treatment regime with regular monitoring.

Points for discussion: This appears to be a case of massive asymptomatic creatine kinase elevation (MACKE), which is rarely documented with use of aripiprazole and quetiapine. This patient's situation was difficult to manage and there was very little literature available for case comparison. Despite TFT normalisation and cessation of sertraline, elevated creatine kinase persisted. It is important to make medical professionals aware of cases such as this, so those treating similar patients can see how other teams have managed such conditions.