title: Pharmacodynamics and pharmacokinetics of cisatracurium in geriatric surgical patients.
abstract: BACKGROUND
  Cisatracurium, one of ten stereoisomers that comprise atracurium, is more potent than atracurium and has less propensity to release histamine. This study compares the pharmacokinetics and pharmacodynamics of cisatracurium in elderly and young patients.
  
  
  METHODS
  Twelve elderly (aged 65-82 yr) and 12 younger patients (aged 30-49 yr) were anesthetized with nitrous oxide, fentanyl, and isoflurane (0.7%, end-tidal). The mechanomyographic response to train-of-four stimulation was assessed every 15 s after the administration of cisatracurium (0.1 mg/kg). Arterial samples were obtained over 6 h. Plasma cisatracurium concentration versus time data were fit to compartmental models. Pharmacokinetic parameters were determined assuming that elimination occurred from the central compartment only. This provides accurate clearance and half-life estimates but underestimates V(ss) (reported herein as V(ss). The pharmacodynamic response was described by the neuromuscular blocking profile.
  
  
  RESULTS
  Onset to 90% paralysis (mean +/- SD) was delayed in the elderly (3.4 +/- 1.0 vs. 2.5 +/- 0.6 min). Recovery profiles were the same for both groups. Elimination half-life was minimally prolonged in the elderly (25.5 +/- 3.7 vs. 21.5 +/- 2.4 min). The Vss was larger in the elderly (126 +/- 16 vs. 108 +/- 13 ml/kg), although the clearances were the same for the two groups (5.0 +/- 0.9 vs. 4.6 +/- 0.8 ml.kg(-1).min(-1).
  
  
  CONCLUSIONS
  There are minor differences in the pharmacokinetics of cisatracurium between elderly and young patients. These differences are not associated with changes in recovery profile after a single bolus dose, although the mean time to onset was approximately 1 min longer in elderly patients.
authors.affiliation: Department of Anesthesiology, College of Physicians and Surgeons of Columbia University, New York 10032, USA.
authors.forename: E
authors.initials: E
authors.lastname: Ornstein
authors.forename: C A
authors.initials: CA
authors.lastname: Lien
authors.forename: R S
authors.initials: RS
authors.lastname: Matteo
authors.forename: N D
authors.initials: ND
authors.lastname: Ostapkovich
authors.forename: J
authors.initials: J
authors.lastname: Diaz
authors.forename: K B
authors.initials: KB
authors.lastname: Wolf
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001279:Atracurium / Q000493:pharmacokinetics* / Q000494:pharmacology; D006801:Humans; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000493:pharmacokinetics*; D013237:Stereoisomerism
chemical_list: D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium