Abstract: The present invention relates to a method for readily determining the binding site on plasma protein and binding displacement effect of a drug having binding affinity to plasma protein, and application of the method to clinical diagnosis. That is to say, the present invention provides a method for determining the binding site with plasma protein of a first drug, comprising reacting the first drug for which the binding site with plasma protein is to be determined, with a second drug of which the binding site with plasma protein is known and plasma protein, and determining the change in the ratio of the first drug freed due to the binding of the plasma protein with the second drug.

Abstract: The present invention relates to a method for readily determining the binding site on plasma protein and binding displacement effect of a drug having binding affinity to plasma protein, and application of the method to clinical diagnosis. That is to say, the present invention provides a method for determining the binding site with plasma protein of a first drug, comprising reacting the first drug for which the binding site with plasma protein is to be determined, with a second drug of which the binding site with plasma protein is known and plasma protein, and determining the change in the ratio of the first drug freed due to the binding of the plasma protein with the second drug.

Abstract: A method of the administration of drugs with binding affinity for plasma protein and drugs regulating the effective ingredient dose of drugs with binding affinity for plasma protein; and a preparation whereby the effective ingredient dose of drugs with binding affinity for plasma protein is regulated. The above administration method is characterized in that, in the administration of a first drug having binding affinity for plasma protein, a second drug having binding affinity for the same plasma protein is administered simultaneously with the first drug or before or after the administration of the first drug to thereby regulate the binding of the first drug to the plasma protein.

Abstract: A method of the administration of drugs with binding affinity for plasma protein and drugs regulating the effective ingredient dose of drugs with binding affinity for plasma protein; and a preparation whereby the effective ingredient dose of drugs with binding affinity for plasma protein is regulated. The above administration method is characterized in that, in the administration of a first drug having binding affinity for plasma protein, a second drug having binding affinity for the same plasma protein is administered simultaneously with the first drug or before or after the administration of the first drug to thereby regulate the binding of the first drug to the plasma protein.