Rhabdomyolysis, Hypocalcemia, and Hypophosphatemia

To the Editor.— In their report of heat hyperpyrexia and rhabdomyolysis associated with hypocalcemia and hypophosphatemia (253:633, 1976), Drs Mason and Thomas commented on the lack of a satisfactory explanation for these findings. It is of particular interest that this patient had been receiving long-term barbiturate therapy, which is known to induce a vitamin-D, deficiency-like syndrome with hypocalcemia and secondary hypophosphatemia.1Additionally, it may be assumed that her oral intake had been inadequate for several days prior to her admission, and that a borderline hypophosphatemia could have then been worsened further by the intravenous infusion of glucose solutions. Hypocalcemia can be seen in the absence of hyperphosphatemia after muscle damage before renal failure sets in.2This condition will lead to excessive parathormone release, which in turn will increase the renal clearance of phosphorus once renal function returns to normal. In the case reported, renal function returned to "normal"