The invention relates to a stable bicarbonate ion-containing drug solution, particularly a bicarbonate-containing drug solution for dialysis in which the stability has been improved by the presence of a phosphate ion. Further, the invention relates to a drug solution for acute blood purification, particularly a dialysate and a substitution liquid for acute blood purification to be mixed before use containing the drug solution. Still further, the invention relates to a dialysate and a substitution liquid for acute blood purification to be mixed before use in which the formation of insoluble fine particles or precipitates is prevented for a long time after mixing and with which hypokalemeia and hypophosphatemia are not caused.
