title: A phase I study on pharmacokinetics and pharmacodynamics of higenamine in healthy Chinese subjects.
abstract: OBJECTIVE
  To investigate the pharmacokinetics, pharmacodynamics, and safety of higenamine, an active ingredient of Aconite root, in healthy Chinese volunteers.
  
  
  METHODS
  Ten subjects received continuous, intravenous infusion of higenamine at gradually escalating doses from 0.5 to 4.0 μg·kg(-1)·min(-1), each dose was given for 3 min. Blood and urine samples were collected at designated time points to measure the concentrations of higenamine. Pharmacodynamics was assessed by measuring the subject's heart rate. A nonlinear mixed-effect modeling approach, using the software Phoenix NLME, was used to model the plasma concentration-time profiles and heart rate.
  
  
  RESULTS
  Peak concentrations (C(max)) of higenamine ranged from 15.1 to 44.0 ng/mL. The half-life of higenamine was 0.133 h (range, 0.107-0.166 h), while the area under concentration-time curve (AUC), extrapolated to infinity, was 5.39 ng·h·mL(-1) (range, 3.2-6.8 ng·h·mL(-1)). The volume of distribution (V) was 48 L (range, 30.8-80.6 L). The total clearance (CL) was 249 L/h (range, 199-336 L/h). Within 8 h, 9.3% (range, 4.6%-12.4%) of higenamine was recovered in the urine. The pharmacokinetics of higenamine was successfully described using a two-compartment model with nonlinear clearance. In the pharmacodynamic model, heart rates were related to the plasma drug concentrations using a simple direct effect model with baseline. The E(0), E(max), and EC(50) were 68 bpm, 73 bpm and 8.1 μg/L, respectively.
  
  
  CONCLUSIONS
  Higenamine has desirable pharmacokinetic and pharmacodynamic characteristics. The results provide important information for future clinical studies on higenamine.
authors.affiliation: Clinical Pharmacology Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Feng
authors.forename: Ji
authors.initials: J
authors.lastname: Jiang
authors.forename: Pei
authors.initials: P
authors.lastname: Hu
authors.forename: Jian-yan
authors.initials: JY
authors.lastname: Zhang
authors.forename: Tao
authors.initials: T
authors.lastname: Liu
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhao
authors.forename: Bi-lu
authors.initials: BL
authors.lastname: Li
mesh_terms: D031841:Aconitum / Q000737:chemistry*; D000328:Adult; D000470:Alkaloids / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D019540:Area Under Curve; D044466:Asian People; D002316:Cardiotonic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D002681:China; D004305:Dose-Response Relationship, Drug; D005260:Female; D006207:Half-Life; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008954:Models, Biological; D017711:Nonlinear Dynamics; D018517:Plant Roots; D044005:Tetrahydroisoquinolines / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D014018:Tissue Distribution; D055815:Young Adult
chemical_list: D000470:Alkaloids; D002316:Cardiotonic Agents; D044005:Tetrahydroisoquinolines; C012348:higenamine