Some pharmacological studies on colstin/ Nalidixic acid interaction with special peference to their effect on the blood

tC olistin is one of the polymyxin group of antibiotics. It is anarrow spectrum antibiotic having a strong bactericidal effect againstgram negative bacilli. whereas, nalidixic acid is one of the quinolonegroup which is extensively used for the control of colibacillosis andsalmonellosis.This study was conducted as a good supplement to the highlypromising forthcoming application of both colistin and nalidixic acidin veterinary practice. The investigation aimed at the possible, if any; some side effects of these drugs that used in a therapeutic doses andreflected as pharmacological, haematological, and/or the effect on the liver and kidney function.1- Biochemical and haematological effects:The effects of colistin (30 mg/kg.b.wt.), nalidixic acid (57.5mglkg.b.wt) and their combination on the liver and kidney functionsas well as on the blood picture of mature healthy rabbits were studied.They were given three times daily for 3 successive days. Bloodsamples were collected one day, two and 4 weeks post-treatment.The obtained results revealed that colistin produces, nonsignificant changes in serum AST, ALT and AP activities as wellas on serum urea, creatinine and uric acid. At the meantime, the blood