Intravenous methylprednisolone-induced hypokalaemic periodic paralysis in a thyrotoxic patient: a case report and literature review.

Hypokalaemic periodic paralysis (HPP) is an uncommon complication of corticosteroid therapy, which may also be seen in thyrotoxicosis. It was mostly described in the Asian population, and it is rare in other ethnic groups. We present the case of a poorly controlled thyrotoxic Caucasian male with thyroid eye disease (TED) who suffered an acute quadriplegic episode caused by severe hypokalaemia and was admitted to the intensive care unit (ITU) within 24 hours of initiating intravenous methylprednisolone (IVMP) infusion. Once his potassium blood levels were repleted, he completely recovered from the episode. Although HPP is rare in the Caucasian population, it can be precipitated in thyrotoxic patients by systemic steroids. Caution should be exercised when administering IVMP in poorly controlled thyrotoxic patients, and we suggest monitoring the potassium levels at regular intervals with ECG monitoring for at least 24 hours in at-risk individuals.