MONOAMINE-OXIDASE-B INHIBITORS - CURRENT STATUS AND FUTURE POTENTIAL

Specific inhibitors of monoamine oxidase type B (MAO-B) constitute a n ovel and expanding pharmacological class. At present, only one compoun d from this class is marketed, selegiline (deprenyl). Other MAO-B inhi bitors that are in various stages of development include lazabemide an d mofegiline, which are differentiated from selegiline by their greate r specificity for MAO-B and the absence of active metabolites. The rol e of MAO-B in the catabolism of amines (essentially, dopamine and phen ylethylamine) and the acceleration of the neurodegenerative process (i .e. oxidative stress) justifies the most common indications for these compounds - Parkinson's disease, Alzheimer's disease, pathological agi ng and, possibly, depression. The possibility that MAO-B inhibitors ma y antagonise the evolution of neuro-degenerative disorders needs furth er scrutiny. Selegiline is the most extensively studied MAO-B inhibito r and is marketed for Parkinson's disease in most Western countries, A dosage of 10 mg/day improves motor symptoms and delays the need for l evodopa in de novo patients. Adverse effects are rare and trivial, alt hough some reports of changes in blood pressure have to be considered seriously. Long term clinical trials with new MAO-B inhibitors are not available. Current data suggest that these drugs are well tolerated a nd have a low potential for drug interactions.