A MODIFICATION OF HAFFNER’S METHOD FOR TESTING ANALGESICS

Abstract

Haffner's tail-pinch method (1) for testing analgesic drugs has been adopted in many laboratories either in the original method (2-4, 17) or in the varieties of modifications (5-7). Certain objections can, however, be raised against the use of the Haffner's method; the intensity of the painful stimulus produced by this method is not shown in figures, neither is it varied quantitatively. The improvement of these disadvantages has been carried out by Eddy (8), Friend and Harris (9), Fleish and Dolivo (10), Brodie et al. (11), Green and Young (12), Yanai (13), Takagi and Kameyama (14), and so on, but there seems still no ideal method exists. The Authors discribe here a simple tail-pinch method, which the intensity of pressure stimulus is varied quantitatively and which satisfies the sensitivity and reproducibility for testing non-narcotic analgesics as well as narcotics.