title: Serum Triamcinolone Levels Following Interlaminar Epidural Injection.
abstract: BACKGROUND
  Lumbar interlaminar epidural steroid injections (ESIs) are one of the most commonly performed procedures in pain medicine, but little is known about the serum levels of steroids following injection into the epidural space. The primary objective of this study was to investigate the pharmacokinetics of fluoroscopy-guided epidural-administered triamcinolone acetonide in a cohort of patients with chronic low-back pain seeking treatment in a pain medicine clinic.
  
  
  METHODS
  The study cohort included 10 patients undergoing a fluoroscopically guided L4-L5 or L5-S1 lumbar interlaminar ESI at a pain medicine specialty clinic. Blood was collected prior to the ESI and on days 1, 2, 4, 6, 8, 14, 21, 28, 35, and 42 following the injection. The sample extract was analyzed by tandem mass spectrometry.
  
  
  RESULTS
  The terminal elimination half-life of epidural-administered triamcinolone in a noncompartmental analysis was 523 hours. In the noncompartmental analysis, peak triamcinolone concentrations of 4.1 ng/mL were detected within 24 hours after administration.
  
  
  CONCLUSIONS
  The pharmacokinetics of epidural-administered triamcinolone is consistent with previously observed adverse effects of the drug on endocrine function. The pharmacokinetics of other epidural-administered steroids should be determined and incorporated in clinical trials to investigate the potential associations between serum levels, clinical outcomes, and potential adverse endocrine effects.
authors.affiliation: From the *Department of Anesthesiology and Divisions of †Pain Medicine, ‡Medical Oncology, and §Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine, Rochester, MN.
authors.forename: W Michael
authors.initials: WM
authors.lastname: Hooten
authors.forename: Wayne T
authors.initials: WT
authors.lastname: Nicholson
authors.forename: Halena M
authors.initials: HM
authors.lastname: Gazelka
authors.forename: Joel M
authors.initials: JM
authors.lastname: Reid
authors.forename: Susan M
authors.initials: SM
authors.lastname: Moeschler
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Lamer
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005471:Fluoroscopy / Q000639:trends; D006801:Humans; D007268:Injections, Epidural; D017116:Low Back Pain / Q000097:blood* / Q000000981:diagnostic imaging / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D014222:Triamcinolone Acetonide / Q000008:administration & dosage* / Q000097:blood*
chemical_list: D014222:Triamcinolone Acetonide