ABSTRACT
Thirty male rabbits were used in this study, they were divided equally to 3 groups, to investigate the effect of repeated daily intramuscular administration of butorphanol or nalbuphene for 4 weeks on some hepatorenal functions. Each drug belonged to the narcotic analgesic group, commonly used; however, their real effect on some body physiological functions still unclear. This study indicated that both drugs induced a severe degree of hepatorenal injury. These actions were evident by increased tremendously aspartate aminotransferase, alanine aminotransferase, serum alkaline phosphatase, serum albumin, blood urea and serum creatinine. Also, the total serum proteins have been reduced. These effects announce that the easy common use of such drugs should be revised; also investigation of the hepatorenal functions should be done before their use