N. Turjanski et al., THE EFFECTS OF ACUTE LEVODOPA WITHDRAWAL ON MOTOR-PERFORMANCE AND DOPAMINERGIC RECEPTOR SENSITIVITY IN PATIENTS WITH PARKINSONS-DISEASE, Journal of Neurology, Neurosurgery and Psychiatry, 56(7), 1993, pp. 771-775
The effects of acute levodopa withdrawal were studied in nine patients
with levodopa related on-off oscillations. One patient withdrew from
the study due to off period confusion and hallucinations. A marked det
erioration in motor disability occurred in all patients following over
night withdrawal of levodopa and a further mild delayed deterioration
was present over a mean withdrawal period of 44 hours. Patients with m
ore severe disease were able to tolerate levodopa withdrawal for a sho
rter period of time than those with milder disease severity. The minim
um therapeutic dose of subcutaneous apomorphine needed to produce a si
milar improvement in patients' mobility, before and after several days
of drug withdrawal, did not differ, thus providing no clinical eviden
ce for alterations in striatal dopamine receptor sensitivity after acu
te levodopa withdrawal.