title: Reducing dosing frequency of carbidopa/levodopa: double-blind crossover study comparing twice-daily bilayer formulation of carbidopa/levodopa (IPX054) versus 4 daily doses of standard carbidopa/levodopa in stable Parkinson disease patients.
abstract: OBJECTIVE
  We compared IPX054, a bilayer tablet of immediate- and extended-release carbidopa/levodopa (CD/LD) given twice daily to standard CD/LD given 4 times daily in patients with stable Parkinson disease (PD).
  
  
  METHODS
  Twelve PD patients with no or mild fluctuations on CD/LD 25/100 mg 4 times daily were randomized to a double-blind crossover comparison with IPX054 (50/200 mg) twice daily. At the end of each 2-week treatment, patients were video recorded while performing a modified Unified Parkinson's Disease Rating Scale motor examination and Rush Dyskinesia Rating Scale at 30-minute intervals over 8.5 hours. The primary outcome measure was the number of videotape epochs rated as "ON" without troublesome dyskinesia by a blinded observer (Wilcoxon signed rank tests).
  
  
  RESULTS
  The 9 men and 3 women had a mean age of 69 years and mean PD duration of 6 years. IPX054 and CD/LD showed no significant differences in the primary outcome measure (mean number of video epochs rated as ON without troublesome dyskinesia; P = 0.14). The mean time to ON was improved with IPX054 (P = 0.014), and the mean modified Unified Parkinson's Disease Rating Scale scores slightly favored IPX054 (14.4 vs 16.9; P = 0.052). Mean Rush Dyskinesia Rating Scale scores were not significantly different between IPX054 and CD/LD (0.45 vs 0.69; P = 0.25). No patient developed troublesome dyskinesias.
  
  
  CONCLUSIONS
  In stable PD patients, no difference was detected between twice-daily treatment with IPX054 and CD/LD given 4 times daily. In this group, substitution with IPX054 reduced dosing frequency while maintaining CD/LD efficacy. In clinical practice, this ease of administration may offer improved treatment compliance.
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, USA. hinsonvk@musc.edu
authors.forename: Vanessa K
authors.initials: VK
authors.lastname: Hinson
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Goetz
authors.forename: Sue
authors.initials: S
authors.lastname: Leurgans
authors.forename: Wenqing
authors.initials: W
authors.lastname: Fan
authors.forename: Tiffany
authors.initials: T
authors.lastname: Nguyen
authors.forename: Ann
authors.initials: A
authors.lastname: Hsu
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000978:Antiparkinson Agents / Q000008:administration & dosage*; D002230:Carbidopa / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004338:Drug Combinations; D020820:Dyskinesias / Q000188:drug therapy / Q000503:physiopathology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000008:administration & dosage*; D008297:Male; D009068:Movement / Q000187:drug effects / Q000502:physiology; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology; D013607:Tablets; D014743:Videotape Recording
chemical_list: D000978:Antiparkinson Agents; D004338:Drug Combinations; D013607:Tablets; D007980:Levodopa; D002230:Carbidopa