Distal renal tubular acidosis and hypokalemic paralysis in a patient with hypothyroidism

A 43- year- old woman on treatment for primary hypothyroidism presented with 1- day progressive weakness of all her limbs and history of similar episodes in the past. Clinical examination revealed grade 2 hyporeflexive weakness. Investigations revealed features of hypokalemia,metabolic acidosis,alkaline urine,and a fractional bicarbonate excretion of 3.5%,consistent with distal renal tubular acidosis. Antithyroid peroxidase and antithroglobulin antibodies were positive,suggesting an autoimmune basis for the pathogenesis of the functional tubular defect. Bicarbonate therapy resulted in a sustained clinical recovery.