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

Clin Neuropharmacol. 2009 Jul-Aug;32(4):189-92. doi: 10.1097/WNF.0b013e3181a27fae.


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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living
  • Aged
  • Antiparkinson Agents / administration & dosage*
  • Carbidopa / administration & dosage*
  • Cross-Over Studies
  • Double-Blind Method
  • Drug Administration Schedule
  • Drug Combinations
  • Dyskinesias / drug therapy
  • Dyskinesias / physiopathology
  • Female
  • Humans
  • Levodopa / administration & dosage*
  • Male
  • Movement / drug effects
  • Movement / physiology
  • Parkinson Disease / drug therapy*
  • Parkinson Disease / physiopathology
  • Tablets
  • Videotape Recording


  • Antiparkinson Agents
  • Drug Combinations
  • Tablets
  • Levodopa
  • Carbidopa