L-Dopa pharmacokinetics studied with microdialysis in patients with Parkinson's disease and a history of malignant melanoma

• Published in: Acta neurologica Scandinavica Vol. 100; no. 4; pp. 231 - 237
• Main Authors: Dizdar, N., Granérus, A.-K., Hannestad, U., Kullman, A., Ljungdahl, Å., Olsson, J.-E., Kågedal, B.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-10-1999; Blackwell
• Subjects: Aged; Anticonvulsants. Antiepileptics. Antiparkinson agents; Antiparkinson Agents - pharmacokinetics; Antiparkinson Agents - therapeutic use; Benserazide - pharmacokinetics; Benserazide - therapeutic use; Biological and medical sciences; Female; gastric emptying; Humans; l-dopa; Levodopa - pharmacokinetics; Levodopa - therapeutic use; Male; Medical sciences; MEDICIN; Medicin och hälsovetenskap; MEDICINE; Melanoma - complications; Microdialysis; Middle Aged; Neuropharmacology; Parkinson Disease - complications; Parkinson Disease - drug therapy; Parkinson's disease; pharmacokinetics; Pharmacology. Drug treatments; Skin Neoplasms - complications; Human; Nervous system diseases; Toxicity; Parkinson disease; Gastric emptying; Malignant tumor; Antiparkinson agent; Cerebral disorder; Concomitant disease; Chemotherapy; Microdialysis; Treatment; Central nervous system disease; Malignant melanoma; Degenerative disease; Biological effect; Levodopa; Pharmacokinetics; Elderly; Extrapyramidal syndrome
• ISSN: 0001-6314; 1600-0404
• DOI: 10.1111/j.1600-0404.1999.tb00386.x

Objectives ‐ The pharmacokinetics of freel‐dopa in blood and tissue of five parkinsonian patients with malignant melanoma was studied with microdialysis. In one case the effect ofl‐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. [13C]‐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.