ABSTRACT
WHAT IS KNOWN AND OBJECTIVE: Thyrotoxic periodic paralysis (TPP) with hypokalaemia is a rare acute phenomenon. Reports of the use of high-dose non-selective ß-blockers describe symptom resolution, but often administration does not occur promptly enough in the treatment course and patients may experience overcorrection and hyperkalaemia. CASE DESCRIPTION: A 37-year-old Hispanic male developed TPP. Patient was successfully treated with low-dose oral propranolol and potassium supplementation with no overcorrection. WHAT IS NEW AND CONCLUSION: Delay in the administration of non-selective ß-blockers may lead to overcorrection of potassium with exogenous supplementation. Low-dose propranolol administered in the Emergency Department was successful in preventing overcorrection of potassium.