Two patients became edematous and their conditions deteriorated markedly after they began to take an antacid for gastrointestinal symptoms. One, a 58-year-old woman, had a history of hepatic cirrhosis; in six days of antacid medication she accumulated 3.7 liters of edema fluid. The other was a 57-year-old man who had had repeated episodes of congestive heart failure; in seven days he accumulated over 5 liters of fluid. Both patients' conditions improved when they stopped taking the antacid. Chemical analyses showed that antacid therapy had increased the sodium intake by about 0.5 Gm. per day. Other antacids in common use were analyzed and were found, in general, to contain amounts of sodium that would be seriously detrimental to patients on the verge of edema.
Rimer DG, Frankland M. SODIUM CONTENT OF ANTACIDS. JAMA. 1960;173(9):995-998. doi:10.1001/jama.1960.03020270021006