Rapid fall of serum phosphorus secondary to antacid therapy

Two patients with marked hypophosphatemia secondary to antacid therapy are described, 1 asymptomatic and the other symptomatic. In contrast to previous reports, these 2 patients were on aluminum hydroxide-containing antacids for relatively short periods of time before the hypophosphatemia occurred. Hypophosphatemia developed after only moderate doses of antacid in the symptomatic patient who was on a low phosphorus diet. An adequate intake of dietary phosphorus or phosphorus-containing antacids may be necessary to avoid a low serum phosphorus in patients taking aluminum hydroxide antacids even when the duration of therapy is as short as 2 weeks and the dose of antacids is not large.