Pargyline is an irreversible selective monoamine oxidase (MAO)-B inhibitor, which possesses higher selectivity to this isoform in comparison with MAO-A. It was approved under brand name eutonyl for the treatment hypertension, but then this drug was discontinued.

Indeloxazine is a neuroleptic, originally developed and marketed in Japan. It is indicated to allay autonomic hyperactivity following cerebral infarction, cerebral haemorrhage or atherosclerosis. It was found to be a weak inhibitor of both type A and type B monoamine oxidases. Indeloxazine-induced facilitation of acetylcholine release in frontal cortex is mediated by endogenous 5-HT and involves at least in part cortical 5-HT4 receptors. As a potential teratogen, Indeloxazine must not be consumed or handled by pregnant or nursing women, or by women who might become pregnant. It was removed from the market reportedly for lack of effectiveness.

Bifemelane is a psychotropic drug, was found to inhibit monoamine oxidase (MAO). It inhibited type A MAO (MAO-A) competitively and type B (MAO-B) noncompetitively and it was a more potent inhibitor of MAO-A than of MAO-B. Bifemelane is an antidepressant and cerebral activator that is used in Japan for the treatment of cerebral infarction patients with depressive symptoms, and in the treatment of senile dementia as well. It also appears to be useful in the treatment of glaucoma.

Lazabemide is a reversible and selective inhibitor of monoamine oxidase B (MAO-B) that was under clinical development against Parkinson's disease, Alzheimer's disease and as an aid to smoking cessation. The development of the drug was discontinued due to liver toxicity.

Debrisoquin is an antihypertensive drug having guanethidine-like properties, which inhibits monoamine oxidase (MAO) and does not enter the brain. Debrisoquine was used for the treatment of hypertension. Debrisoquine hydroxylation phenotype has been the most used test in humans to evaluate CYP2D6 activity. Two debrisoquine hydroxylation phenotypes have been described: poor and extensive metabolizers. A group with a very low debrisoquine metabolic ratio within the extensive metabolizers, named ultrarapid metabolizers, has also been distinguished. This CYP2D6 variability can be for a large part alternatively determined by genotyping, which appears to be of clinical importance given CYP2D6 involvement in the metabolism of a large number of commonly prescribed drugs.