Mofegiline (MDL 72,974A or (E)-2-(4-fluorophenethyl)-3-fluoroallylamine, hydrochloride), is a selective and irreversible inhibitor of monoamine oxidase type B (MAO-B) both in vitro and in vivo. In addition, mofegiline inhibits semicarbazide-sensitive amine oxidase activity from human serum and saphenous vein. In phase II studies, MDL 72,974A is proving to be a useful adjunct to conventional therapy of Parkinson's disease. It seems mofegiline development was discontinued.

Sembragiline is a potent, selective, long-acting, and reversible monoamine oxidase B (MAO-B) inhibitor developed as a potential treatment for Alzheimer's disease (AD). Sembragiline was involved in phase II clinical trial to evaluate its the safety, tolerability, and efficacy in patients with moderate AD. In addition, the drug was studied for smoking cessation, however, it failed to demonstrate efficacy during a phase II proof-of-concept trial.

Rolicyprine (EX-4883) is an antidepressant. This compound is a potent inhibitor of monoamine oxidase in vivo. One study found that rolicyprine must be biotransformed before it is a pharmacologically active compound. Once it is activated, Rolicyprine appears to have a pharmacology like that of the antidepressant tranylcypromine. It was suggested that the products of this biotransformation are tranylcypromine and pyrrolidone carboxylic acid. No information on current use of rolicyprine is available.

Brofaromine (proposed brand name Consonar) is a reversible inhibitor of monoamine oxidase A (RIMA) developed by Ciba-Geigy for depression and anxiety disorders treatment. Brofaromine induces short, reversible and selective inhibition of brain MAO of type A in a dose-dependent manner in all brain regions. The largest decrease being found respectively in hippocampus, striatum and prefrontal cortex, regions having a rich monoaminergic innervation. Brofaromine also acts as a serotonin reuptake inhibitor, and its dual pharmacologic effects offered promise in the treatment of a wide spectrum of depressed patients while producing less severe anticholinergic side effects in comparison with older standard drugs like the tricyclic antidepressants. The compound was primarily researched in the treatment of depression and anxiety but its development was dropped before it was brought to market.

Pirlindole is a selective and reversible inhibitor of monoamine oxidase (MAO) subtype A (MAO-A). It exerts an inhibitory effect on noradrenaline and 5-hydroxytryptamine reuptakes. It has no effect on the dopaminergic and cholinergic systems. It has only a low potential for amplifying tyramine and noradrenaline pressor effect, which makes one expect that it will not be at the basis of a ‘cheese effect’. Pirlindole was approved in some European and non-European countries for the treatment of depression. The antidepressant efficacy and safety of pirlindole have been demonstrated in a number of placebo- and active comparator-controlled studies and are supported by many years of clinical experience in the treatment of depression. The drug's efficacy and safety have also been demonstrated in the treatment of fibromyalgia syndrome. Pirlindole has a favorable tolerability profile, with no deleterious effect on cardiovascular dynamics. The effect of pirlindole on sensorimotor performance relevant to driving a motor vehicle is similar to that of placebo, as pirlindole appears to have an activating rather than a sedating antidepressant profile. Pirlindole prevented qualitative alteration (transformation) in the catalytic activity of membrane-bound type A monoamine oxidases (MAO-A), pathogenetically important for the development of the audiogenic seizures.

Almoxatone (compound MD 780236) is a selective inhibitor of the B-form of monoamine oxidase. Inhibition involves an initial non-covalent interaction between enzyme and inhibitor followed by a time-dependent process resulting in irreversible inhibition. The initial, reversible, phase of inhibition was found to be competitive with respect to phenethylamine and 5-hydroxytryptamine, and a comparison of the Ki values indicated the affinity of the inhibitor for the B-form of the enzyme to be some 7-fold greater than its affinity for the A-form. In vitro studies of the effect of MD 780236, a selective monoamine oxidase (MAO)-B inhibitor, on a semicarbazide-sensitive amine oxidase (SSAO) in rat testis and lung showed that this compound dose-dependently inhibited SSAO activity. The inhibition of SSAO by MD 780236 was non-competitive with or without preincubation, with a Ki value of 110 muM. Although MD 780236 is a selective and "suicide substrate" inhibitor of MAO-B, these present results indicate that this compound may also inhibit SSAO activity, but by a mechanism different from that for MAO-B. Almoxatone is stereoselective. The enantiomer with the R absolute configuration (MD 240928) is fully reversible in ex-vivo conditions, whereas the S-enantiomer (MD 240931) has kept the irreversible component of the inhibition seen with MD 780236. The corresponding racemic alcohol derivative (MD 760548) is also a short-acting inhibitor of the B form of MAO; its S-enantiomer, which has an absolute configuration corresponding to that of MD 240928, has a selectivity towards the B form superior to that of the other enantiomer. Almoxatone was patented as an antidepressant and antiparkinsonian agent.

Amiflamine is a selective and reversible inhibitor of monoamine oxidase (MAO) type A which exerts a preferential effect on serotonin (5-HT) catabolism. The (+)-enantiomer is the active stereoisomer. In a series of p-aminosubstituted phenethylamines, the ( + )-enantiomer of the compound amiflamine (4-dimethylamino-2-a-dimethylphenethylamine) was found to be a potent, selective, and reversible MAO type A inhibitor. Amiflamine (FLA 336(+] and its two metabolites, FLA 788(+) and FLA 668(+) were found to be competitive inhibitors of the activity of monoamine oxidase-A in homogenates of human hypothalamus and liver obtained at autopsy. Ki values, determined at pH 7.2, were 1.3, 0.3 and 22 uM (liver) and 0.8, 0.2 and 14 uM (hypothalamus) for amiflamine, FLA 788(+) and FLA 668(+), respectively. Monoamine oxidase-B activity was only weakly inhibited by the compounds. This initial phase I study in six normal subjects showed that the new MAO inhibitor amiflamine can be tolerated in single oral doses up to 80 mg without significant pharmacologic effects. Doses up to 60 mg were tolerated without any subjective or objective effects.

Cimemoxin (INN), or cyclohexylmethylhydrazine, is a hydrazine monoamine oxidase inhibitor and antidepressant which was never marketed. Currently, Cimemoxin used as a reagent in organic synthesis.

Octamoxine (ximaol), a monoamine oxidase inhibitor was used as an antidepressant to treat mental depression. Now this drug is no longer marketed.

Cimoxatone is a fully reversible inhibitor selective for the A form of monoamine oxidase. Oral administration of Cimoxatone increased brain noradrenaline, dopamine, and serotonin and decreased DOPAC , 5-HIAA, and 3-methoxy-4-hydroxyphenylethylene glycol sulfate.