In true white rat fashion, I am testing this one even as we type. It is presently 4:18 PM here and I've been dyskinetic for the last couple of hours and expect to be so for a couple more. So, I took a quarter teaspoon at 4:15 and will report later.


1. Mov Disord. 1998 May;13(3):414-7.

A trial of dextromethorphan in parkinsonian patients with motor response
complications.

Verhagen Metman L, Blanchet PJ, van den Munckhof P, Del Dotto P, Natté R, Chase
TN.

Experimental Therapeutics Branch, National Institute of Neurological Diseases and
Stroke, National Institutes of Health, Bethesda, Maryland 20892-1406, USA.

The effects of the NMDA antagonist dextromethorphan (DM) on levodopa-associated
dyskinesias and motor fluctuations were studied in patients with advanced
Parkinson's disease. During initial open-label dose escalation, 6 of 18 patients
reported a beneficial effect at their individually determined optimal DM dose
(range, 60-120 mg/day). The 12 remaining patients either experienced reversible
side effects, particularly mild drowsiness, or decreased levodopa efficacy, and
were therefore excluded from the study. The six responders entered the
double-blind, placebo-controlled, crossover study with two 2-week arms separated
by 1 week wash-out. On the last day of each arm, motor ratings were performed
every 20 minutes for 8 consecutive hours. In addition, motor complications and
Activities of Daily Living (ADL) were assessed using the Unified Parkinson's
Disease Rating Scale (UPDRS) and patient diaries. With DM, dyskinesias improved
by 25% according to physician's ratings and by 40% according to UPDRS interviews,
without compromising the anti-Parkinson effect of levodopa. Motor fluctuations
and ADL scores also improved significantly. Although the narrow therapeutic index
of DM limits its clinical usefulness, these findings support the view that drugs
acting to inhibit glutamatergic transmission at the NMDA receptor can ameliorate
levodopa-associated motor complications.

PMID: 9613730 [PubMed - indexed for MEDLINE]


1. Amino Acids. 1998;14(1-3):75-82.

Blockade of glutamatergic transmission as treatment for dyskinesias and motor
fluctuations in Parkinson's disease.

Verhagen Metman L, Del Dotto P, Blanchet PJ, van den Munckhof P, Chase TN.

National Institute of Neurological Diseases and Stroke, National Institutes of
Health, Bethesda, Maryland, USA.

In animal models of Parkinson's disease (PD), glutamate antagonists diminish
levodopa (LD)-associated motor fluctuations and dyskinesias. We sought to
investigate if these preclinical observations can be extended to the human
disease, by evaluating the effects of three non-competitive NMDA antagonists
(dextrorphan, dextromethorphan and amantadine) on the motor response to LD in
patients with advanced PD. In four separate trials, adjuvant therapy with these
drugs reduced LD-induced dyskinesias and motor fluctuations. These findings
support the view that drugs acting to inhibit glutamatergic transmission at the
NMDA receptor can ameliorate LD associated motor response complications.

PMID: 9871445 [PubMed - indexed for MEDLINE]


1. Neurology. 1998 Jul;51(1):203-6.

Dextromethorphan improves levodopa-induced dyskinesias in Parkinson's disease.

Verhagen Metman L, Del Dotto P, Natté R, van den Munckhof P, Chase TN.

Experimental Therapeutics Branch, National Institute of Neurological Diseases and
Stroke, National Institutes of Health, Bethesda, MD 20892-1406, USA.

OBJECTIVE: This study assessed the effects of the N-methyl-D-aspartate (NMDA)
antagonist dextromethorphan (DM) on levodopa-induced dyskinesias in Parkinson's
disease (PD). BACKGROUND: Recent experimental evidence suggests that increased
synaptic efficacy of NMDA receptors expressed on basal ganglia neurons may play a
role in the pathophysiology of levodopa-induced motor response complications.
METHODS: DM was given to six PD patients with motor fluctuations in a
double-blind, placebo-controlled, cross-over study. At the end of each 3-week
study arm, patients received several brief i.v. levodopa infusions while
parkinsonian symptoms and dyskinesias were frequently scored. Levodopa
dose-response curves for antiparkinsonian and dyskinetic effects were then
compared for each study arm. RESULTS: With DM, average and maximum dyskinesia
scores improved by >50%, without compromising the antiparkinsonian response
magnitude or duration of levodopa, although in some subjects the levodopa
threshold dose was slightly higher with DM than with placebo. CONCLUSIONS: These
findings support the view that drugs acting to inhibit glutamatergic transmission
at the NMDA receptors can ameliorate levodopa-associated dyskinesias.

PMID: 9674803 [PubMed - indexed for MEDLINE]

Remember a couple of things about dextromethorphan-
1- Less is more. Take the least dose that gives you the effect as a little more will reverse the effect.
2- When you do your research, be aware that dextromethorphan gives the Drug Warriors apoplexy because it is so readily available and has so few side effects. So they put out a lot of lies about it.

BTW, it is now 4:41 PM and my dk is down by a third.