<prompt> Thyrotoxic periodic paralysis TPP is usually due to hypokalemia. It is best treated with:PotassiumMagnesiumHydrationPropranolol  <response>: Thyrotoxic periodic paralysis is due to hypokalemia. MUST KNOW Hypokalemia is profound and accompanied by hypophosphatemia and hypomagnesemia. MECHANISM: Direct and indirect activation of Na,K-ATPase Increased uptake of K by muscle and other tissues Inrease in beta adrenergic activity Propranolol 3 mgkg rapidly reverses the hypokalemia, hypophosphatemia, and paralysis. Ref: Harrison, Edition-18, page- 352. 