TABLE 1
Dose-effect relationship laws used by different schools Modified from “Quantitation of Synergism and Antagonism of Two or More Drugs by Computerized Analysis,” Chou TC, in Synergism and Antagonism in Chemotherapy (Chou TC and Rideout DC eds) pp 223–244. Copyright 1991 with permission from Elsevier.
| POWER LAW (Nordling, 1953; Armitage and Doll, 1954) | fa = bDk; log(fa) = k log(D) + log b |
| PROBIT (Bliss, 1939; Finney, 1947, 1952, 1971) | fa =  where Y = (log D - log Dm)/σ |
| LOGIT (Berkson, 1946; Thompson, 1947) | fa = 1[1 + e-(α + βlog D)] |
| The median-effect equation of the MASS-ACTION LAW (Chou, 1974, 1976) | fa/fu = (D/Dm)m; log[(fa)-1 - 1]-1 = m log (D) - m log(Dm) |
-
D, dose; Dm, median-effect dose; m, kinetic order; fa, fraction affected; fu, fraction unaffected; σ2, variance; Y (PROBIT – 5) or normal equivalent deviate; a, k, α, and β, undefined constants