Using liquid levodopa in the treatment of Parkinson's disease. A practical guide.
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.
Kurth
M C
MC
Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
D000284:Administration, Oral; D000375:Aging / Q000378:metabolism; D000978:Antiparkinson Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D002490:Central Nervous System / Q000187:drug effects / Q000378:metabolism; D005746:Gastric Emptying / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D007980:Levodopa / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D010300:Parkinson Disease / Q000188:drug therapy*; D012996:Solutions
D000978:Antiparkinson Agents; D012996:Solutions; D007980:Levodopa