ArticleOppel F, Schulze G.
Pharmakopsychiatr Neuropsychopharmakol. 1978 Mar;11(2):76-80.
The influence of prodipin, a putative dopamine releasing compound, on the concentration of homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the spinal liquor of 28 patients with Parkinson's disease was investigated. The patients were divided into three groups. In group 1 the combined antiparkinson therapy was interrupted, and 20 mg prodipin was infused. In group 2 and 3 the therapy was continued, while an additional 20 mg of prodipin was administered by infusion only to group 3. 4 Liquor-samples were obtained from each patient: 1 basic value and three additional samples 5, 8 and 24 hours after administration of 2 g probenecid. The base concentration of HVA was 15 ng/ml and this was not increased by probenecid in group 1; the concentration of 5-HIAA was 11.6 ng/ml and this was doubled by probenecid to 22.9 ng/ml. The HVA concentration increased to a maximum of 28.9 ng/ml during continued therapy (group 2); the elevated 5-HIAA remained unchanged. Prodipin does not cause an alteration in metabolite concentration in cases of interrupted therapy (group 1), but leads, in the case of continued therapy, to a 1.8-fold increase in HVA, and a 1.6-fold increase in 5-HIAA (group 3).