In Reply:-We read with interest the letter from Drs. Goudas and Carr. We agree that their proposed graphic analysis may improve the presentation of results in some studies involving analgesic drugs. However, in the case of our work, it would be extremely difficult to present the results from eight different experimental groups in the fashion suggested. In addition, Drs. Goudas and Carr should detail specifically what kind of synergistic or additive interactions between drugs that this kind of presentation would provide. Typically synergistic or additive interactions are evaluated using a formal isogolographic analysis, an analysis that we do not believe was feasible in our study.

Marc DeKock, M.D.

Department of Anesthesiology; St. Luc Hospital; Avenue Hippocrate 10-1821; 1200 Brussels; Belgium;

(Accepted for publication August 6, 1998.)