ATRACURIUM O Onset Slow Duration Intermediate O Dose -0.5-0.6 mg/kg BW. O Histamine releaser O Metabolism unique - I. Hoffmann elimination - Spontaneous base catalyzed degradation. II. Ester hydrolysis by non-specific plasma esterase. Laudanosine is a major metabolite of both path ways. This metabolite if accumulate in blood causes CNS stimulation. Metabolism is independent of Liver and kidney this is very good NDNB drug for pts with derangement of liver and kidney. Very useful in_ 1) Acute /chronic renal dysfunction 2) Acute/chronic hepatic dysfunction 3) Pediatric 4) Old age 5) Pregnancy CISATRACURIUM Purified CIS-isomer of Atracurium similar profile as Atracurium except i More potent so less dose is used clinically ii Fuher less histamine release so more hemodynamic stable iii Slow onset.