Hostname: page-component-76fb5796d-vvkck Total loading time: 0 Render date: 2024-04-29T10:52:42.539Z Has data issue: false hasContentIssue false

COMT Inhibitors in Parkinson's Disease

Published online by Cambridge University Press:  02 December 2014

Jean Rivest
Affiliation:
Centre Universitaire de Santé de l'Estrie, Fleurimont, Quebec
C. Lynn Barclay
Affiliation:
University of Ottawa, Ottawa, Ontario
Oksana Suchowersky
Affiliation:
University of Calgary, Calgary, Alberta
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The COMT inhibitors, tolcapone and entacapone, are a new class of Parkinson's medications. By inhibiting the enzyme catechol-o-methyl-transferase (COMT), they prevent peripheral degradation of levodopa, allowing a higher concentration to cross the blood-brain barrier. Pharmacokinetic studies have shown that both tolcapone and entacapone significantly prolong the elimination half life, and increase the area under the curve of levodopa without increasing C max. Clinical studies with COMT inhibitors have shown benefit in both stable and fluctuating PD patients with improvement in motor function with lower levodopa doses. Fluctuating patients also had increased “on” time and reduced “wearing off”. Side effects were most commonly related to increased dopaminergic stimulation. Specific side effects included diarrhea and elevated liver enzymes. The recent reports of three cases of fulminant hepatitis with the use of tolcapone has led many countries to remove this compound from their market. Concerns about a possible class effect should impose close monitoring of liver function tests with the use of any of the nitrocatechols.

Résumé

RÉSUMÉ

Inhibiteurs de la COMT dans la maladie de Parkinson. Les inhibiteurs de la COMT, le tolcapone et l'entacapone, appartiennent à une nouvelle classe de médicaments antiparkinsoniens. En inhibant l'enzyme catéchol-o-méthyl-transférase (COMT), ils empêchent la dégradation périphérique de la lévodopa permettant ainsi à des con-centrations plus élevées de traverser la barrière hémato-encéphalique. Des études de pharmacocinétique ont montré que le tolcapone et l' entacapone prolongent significativement la demi-vie et augmentent l'aire sous la courbe de la lévodopa sans augmenter le Cmax. Les études cliniques avec des inhibiteurs de la COMT ont montré des bénéfices tant chez les patients stables que chez ceux qui présentent des fluctuations, avec une amélioration de la fonction motrice avec des doses inférieures de lévodopa. Les patients fluctuants ont également présenté une augmentation du temps où ils sont fonctionnels et une diminution de la perte d'effet. Les effets secondaires étaient le plus souvent reliés à l'augmentation de la stimulation dopaminergique. La diarrhée et une élévation des enzymes hépatiques sont des effets secondaires spécifiques de ces médicaments. Trois cas d'hépatite fulminante avec le tolcapone ont incité plusieurs pays à retirer ce produit du marché. À cause de la possibilité qu'il s'agisse d'un effet de classe, on doit faire une surveillance étroite des épreuves de fonction hépatique dans l'utilisation de tous les nitrocatéchols.

Type
Research Article
Copyright
Copyright © The Canadian Journal of Neurological 1999

References

1. Cedarbaum, J. Clinical pharmacokinetics of anti-parkinsonian drugs. Clin Pharmacokinet 1987; 13: 141178.Google Scholar
2. Mannistö, PT, Kaakkola, S. Rationale for selective COMT inhibition as adjuncts in the drug treatment of Parkinson’s disease. Pharmacol Toxicol 1990; 66: 317323.Google Scholar
3. Nutt, JG, Woodward, WR, Becker, RM, et al. Effects of peripheral catechol-O-methyltransferase inhibition on the pharmacokinetics and pharmacodynamics of levodopa in parkinsonian patients. Neurology 1994; 44:913919.Google Scholar
4. Hauser, RA, Molho, E, Shale, H et al. A pilot evaluation of the tolerability, safety and efficacy of tolcapone alone and in combination with oral selegeline in untreated Parkinson’s disease patients. Mov Disord 1998; 13: 643747.Google Scholar
5. Teräväinen, H, Kaakkola, S, Järvinen, M, Gordin, A. Selective COMT Inhibitor, Nitecapone, In: eds Parkinson’s disease. 42nd Annual Meeting of the American Academy of Neurology, Miami Beach, Florida,1990 (abstract).Google Scholar
6. Dingemanse, J, Jorga, KM, Schmitt, M, et al. Integrated pharmacokinetics and pharmacodynamics of the novel catechol-O-methyl-transferase inhibitor tolcapone during first administration to humans. Clin Pharmacol Ther 1995; 57: 508517.Google Scholar
7. Dingemanse, J, Jorga, KM, Zürcher, G, Schmitt, M, Sedek, G, Prada, MD et al. Pharmacokinetic-pharmacodynamic interaction between the COMT inhibitor tolcapone and single-dose lev-odopa. Br. J. Clin Pharmacol 1995; 40: 253262.Google Scholar
8. Nutt, JG. Levodopa: rational and irrational pharmacology. Ann Neurol 1994; 36: 45.Google Scholar
9. Waters, CH, Kurth, M, Bailey, P, et al. Tolcapone in stable Parkinson’s disease: efficacy and safety of long-term treatment. Neurology 1997; 49: 665671.Google Scholar
10. Suchowersky, O, Martin, WRW, Bailey, et al. Benefit of tolcapone in patients with early Parkinson’s disease. Neurology 1996; 46 (Suppl 2): A159.Google Scholar
11. Rinne, UK, Larsen, JP, Siden, A, Worm-Petersen, J and the NomeCOMT Study Group. Entacapone enhances the response to levodopa in Parkinsonian patients with motor fluctuations. Neurology 1998; 51: 13091314.Google Scholar
12. Parkinson Study Group. Entacapone improves motor fluctuations in levodopa treated Parkinson’s disease patients. Ann Neurol 1997, 42: 747755.Google Scholar
13. Kurth, MC, Adler, CH, St-Hilaire, M, et al. Tolcapone improves motor function and reduces levodopa requirements in patients with Parkinson’s disease experiencing motor fluctuations: a mul-ticentres, double-blind, randomized, placebo-controlled trial. Neurology 1997; 48: 8187.Google Scholar
14. Rajput, AH, Martin, W, Saint-Hilaire, M-H, Dorflinger, E, Pedder, S. Tolcapone improves motor function in the Parkinsonian patients with the “wearing-off” phenomenon: a double-blind, placebo-controlled, multicenter trial. Neurology 1997; 49: 10661071.Google Scholar
15. Baas, H, Beiske, AG, Ghika, J, Jackson, M, Oertel, WH, Poewe, W & al. Catechol-O-methyltransferase inhibition with tolcapone reduces the “wearing-off” phenomenon and levodopa requirements in fluctuating parkinsonian patients. J Neurol Neurosurg Psychiatry 1997; 63: 421428.Google Scholar
16. Guttman, M and The Canadian Tolcapone Fluctuating Study Group. Comparison of tolcapone 100 mg vs 200 mg in fluctuating Parkinson’s Disease (PD) patients. Mov Disord 1998; 13 (Suppl 2): 175.Google Scholar
17. Suchowersky, O, Panisset, M, Bailey, P et al. Comparison of two different doses of tolcapone in non-fluctuating Parkinson’s disease patients. Mov Disord 1998; 13 (Suppl 2): 175 Google Scholar
18. Assal, F., Spahr, L, Hadengue, et al. Tolcapone and fulminant hepatitis. Lancet 1998; 352: 9132.Google Scholar
19. Agid, A, Destée, A., During, F, Monstatruc, JL, Pllack, P on behalf of the French Tolcapone Study Group. Tolcapone, bromocriptine and Parkinson’s disease. Lancet 1997; 350: 712713.Google Scholar