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L‐Dopa pharmacokinetics studied with microdialysis in patients with Parkinson's disease and a history of malignant melanoma
Author(s) -
Dizdar N.,
Granérus A.K.,
Hannestad U.,
Kullman A.,
Ljungdahl Å.,
Olsson J.E.,
Kågedal B.
Publication year - 1999
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/j.1600-0404.1999.tb00386.x
Subject(s) - benserazide , microdialysis , pharmacokinetics , medicine , melanoma , gastric emptying , parkinson's disease , gastroenterology , levodopa , pharmacology , disease , stomach , central nervous system , cancer research
Objectives ‐ The pharmacokinetics of free l ‐dopa in blood and tissue of five parkinsonian patients with malignant melanoma was studied with microdialysis. In one case the effect of l ‐dopa treatment on 5‐S‐cysteinyldopa and the melanoma was studied. Gastric emptying and its effects on free l ‐dopa in blood were also investigated in one of the patients. Methods ‐ Five patients were given 100 mg l ‐dopa with 25 mg benserazide. Blood and dialysates from the circulation and fatty tissue were collected for analysis. [ 13 C]‐Octanoic breath test was used for analyzing gastric half‐emptying time. Results ‐ Four of the patients had similar pharmacokinetic patterns for l ‐dopa and a significant ( P < 0.05) increase of serum 5‐S‐cysteinyldopa occurring 30 min after l ‐dopa intake. Delayed l ‐dopa peaks and slow gastric half‐emptying time were found in 1 patient. A dose‐dependent increase of 5‐S‐cysteinyldopa occurred but no melanoma metastases were seen during long‐term l ‐dopa therapy. Conclusion ‐ l ‐dopa therapy increases 5‐S‐cysteinyldopa levels but does not seem to cause progress of melanomas. Gastric emptying impacts l ‐dopa pharmacokinetics.