Reversible monoamine oxidase inhibitors RIMA type

One Type B MAOl (i.e., selegiline) has a low propensity to cause hypertensive and hyperpyrexic reactions, but there is scant information on its use for PD. On the other hand, among the selective and reversible inhibitors of monoamine oxidase A (RIMAs) such as brofaromine, some may be as effective as phenelzine without posing the same risks. 

Monoamine-oxidase inhibitors (MAOIs) make up the second group and include, isocarboxazid, tranylcypromine and phenelzine, which are now used less commonly due to severe side-effects, especially through a potentially dangerous interaction with foodstuffs. A newer agent, moclobemide (a RIMA, reversible, selective type A monoamine-oxidase inhibitor) is said to give less dangerous interactions with foodstuffs. See monoamine-oxidase inhibitors. 

Selective serotonin reuptake inhibitors (SSRIs) are regarded as first-line treatment in social phobia. Fluvoxamine, paroxetine, and sertraline have been shown to be effective in double-blind placebo-controlled studies. - The irreversible monoamine oxidase inhibitor (MAOI) phenelzine shows robust results in terms of efficacy and has demonstrated (at least anecdotally), its efficacy in improving some of the cognitive aspects associated with SAD. However, phenelzine is usually less well tolerated than alternative treatments due to its associated dietary restrictions and adverse side-effect profile, including sedation and postural hypotension. Results with the reversible inhibitor of monoamine oxidase type A (RiMA) mociobemide are inconsistent. 

MAOI non-selective monoamine oxidase (A/B) inhibitors RIMA reversible inhibitor of monamine oxidase type A SSRI selective serotonin (5-HT) reuptake inhibitors SNRI serotonin/noradrenaline reuptake inhibitor SNARI selective noradrenaline (NA) reuptake inhibitor NA = 5-HT — DA potency of the drug is very similar in raising the level of both (or all three) monamines NA > 5-HT more selective for NA 5-HT>NA more selective for 5-HT NA increases the release of NA. 

FIGURE 6-24. Shown in this figure also is the combination of a monoamine oxidase (MAO) inhibitor and tyramine. However, in this case the MAO inhibitor is of the reversible type (reversible inhibitor of MAO A, or RIMA). In contrast to the situation shown in the previous figure (Fig. 6— 23), the accumulation of norepinephrine (NE) caused by tyramine (indicated in red circle 1) can actually strip the RIMA off MAO (arrow 2). MAO, now devoid of its inhibitor, can merrily do its job, which is to destroy the NE (red circle 3) and thus prevent the dangerous accumulation of NE. Such a reversal of MAO by NE is only possible with a RIMA and not with the classical MAO inhibitors, which are completely irreversible. 

Reversible inhibitors of monoamine oxidase type A (RIMAs)... 

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