title: Analysis of multidrug effects by parameter method.
abstract: OBJECTIVE
  To set up a new analytic method for multidrug effects.
  
  
  METHODS
  Based on the principles of the target site kinetics and the equieffective test, a new mathematical model was set as Q = (Eo-Ee)/magnitude of Ee x W-sx x T (-1 < Q < 1 addition, Q < or = -1 antagonism, Q > or = 1 synergism) where Eo = a fitted value of the observed effect of a combination, Ee = an expected value of combined effect, W = an equieffective criterion decided by a special field, sx = a common standard error of Eo and Ee, and T = a value of one-sided t0.05. All the calculations were completed with computer. Dose-effect data from different types of experiments were fitted by the new model and the results were compared with those of other methods.
  
  
  RESULTS
  This parameter method dealt with different types of data well fitted with the Hill equation, and was not limited to analyze receptor interaction of drugs, or the number of combined drugs. A series of Q values was obtained from all levels of dose-effect for a systematic analysis. The analysis took the criterion of a special field and laboratory error into account.
  
  
  CONCLUSIONS
  This parameter method can effectively analyze the multidrug effects.
authors.affiliation: Institute of Clinical Pharmacology, Yijishan Hospital, Wannan Medical College, Wuhu, China.
authors.forename: Q S
authors.initials: QS
authors.lastname: Zheng
authors.forename: R Y
authors.initials: RY
authors.lastname: Sun
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D017609:Barium Compounds / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002712:Chlorides / Q000494:pharmacology; D004285:Dogs; D004336:Drug Antagonism; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D004837:Epinephrine / Q000494:pharmacology; D006168:Guinea Pigs; D006801:Humans; D007082:Ileum / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D008962:Models, Theoretical; D009119:Muscle Contraction / Q000187:drug effects; D013274:Stomach Neoplasms / Q000473:pathology; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D017609:Barium Compounds; D002712:Chlorides; C024986:barium chloride; D001285:Atropine; D007545:Isoproterenol; D000109:Acetylcholine; D004837:Epinephrine