Metabolic alkalosis and myoclonus from antacid ingestion

A patient with a history of cerebrovascular disease, hypertension, and previous gastrectomy developed metabolic alkalosis and myoclonus. His medications included the anti-hypertensive agents nicardipine hydrochloride, delapril, prazosin; dihydroergotoxin and ticlopidine for cerebral infarction; estazolam for insomnia; azuren-L-glutamine compound and S-M powder. In addition, he had taken 12 grams per day of Ohta's Isan antacid, which contained 625 mg sodium bicarbonate per 1.3 g of antacid powder over a 6-month period. This antacid is commonly used in Japan. This is the first report of a case of metabolic alkalosis and myoclonus secondary to ingestion of a commercially available antacid in Japan.