Acetazolamide treatment in hypokalemic periodic paralysis: a metabolic and electromyographic study

The beneficial action of acetazolamide in the treatment of hypokalemic periodic paralysis was studied in 3 patients, a woman and 2 of her sons. All 3 subjects showed a disturbed electromyogram with a lack of functioning motor units, even when no weakness of the muscle was observed. Bicarbonate-induced alkalosis caused aggravation of the electromyographic pattern. In 1 subject a paralytic attack was observed during alkalosis, which was abolished with intravenous acetazolamide. A similar beneficial action on previously disturbed electromyographic pattern was observed during ammonium chloride infusion. After 1 wk of treatment with acetazolamide the electromyographic records were found to be almost normal in all 3 subjects. The effect of acetazolamide on these 3 patients could not be explained by its action on serum potassium levels, which did not change. It appears that the acidosis caused by acetazolamide has a beneficial effect on the disturbed muscle excitability found in these patients.