Using liquid levodopa in the treatment of Parkinson's disease. A practical guide

Drugs Aging. 1997 May;10(5):332-40. doi: 10.2165/00002512-199710050-00002.


Many patients with Parkinson's disease develop both involuntary movements from and a critical dependency on, levodopa therapy as their disease progresses. This results in a narrow therapeutic window in which blood concentrations of levodopa can achieve optimal control of parkinsonian symptoms. The short half-life of levodopa, combined with loss of intraneuronal storage capacity for levodopa as the disease progresses, results in patients experiencing marked motor fluctuations complicated by medication-induced dyskinesias. When given in tablet form, the dosage of levodopa (which is usually combined with a decarboxylase inhibitor such as carbidopa or benserazide) often cannot be titrated adequately, and the drug may become unpredictable in its ability to relieve parkinsonian symptoms. A solution of levodopa and carbidopa, stabilised using ascorbic acid, offers a means of delivering a titrated amount of levodopa at regular intervals. Solutions pass through the stomach faster than solids, affording more rapid symptomatic relief in some patients with Parkinson's disease.

Publication types

  • Review

MeSH terms

  • Administration, Oral
  • Aging / metabolism
  • Antiparkinson Agents / adverse effects
  • Antiparkinson Agents / pharmacokinetics
  • Antiparkinson Agents / pharmacology
  • Antiparkinson Agents / therapeutic use*
  • Central Nervous System / drug effects
  • Central Nervous System / metabolism
  • Gastric Emptying / drug effects
  • Humans
  • Injections, Intravenous
  • Intestinal Absorption
  • Levodopa / administration & dosage
  • Levodopa / adverse effects
  • Levodopa / pharmacokinetics
  • Levodopa / pharmacology
  • Levodopa / therapeutic use*
  • Parkinson Disease / drug therapy*
  • Solutions


  • Antiparkinson Agents
  • Solutions
  • Levodopa