Reversible inhibitor of monoamine oxidase A

From Wikipedia, the free encyclopedia

Skeletal formula of moclobemide, the prototypical reversible inhibitor of monoamine oxidase type A

Ribbon diagram of a monomer of human MAO-A, with FAD and clorgiline bound, oriented as if attached to the outer membrane of a mitochondrion. From PDB 2BXS.

Reversible inhibitors of monoamine oxidase type-A (RIMAs) are a family of psychiatric drugs and natural compounds that inhibit monoamine oxidase temporarily and reversibly. They are mostly used for alleviating depression and dysthymia. Because their action is short-lived and selective, they have a better safety profile than the older MAOIs.

Moclobemide, brofaromine, and some beta-carbolines, such as harmaline, are examples of RIMAs.^[1][2]

[edit] Functionality and safety

RIMAs, a subset of monoamine oxidase inhibitors (MAOIs), inhibit only isoenzyme A and are reversible. They are displaced from monoamine oxidase in the presence of tyramine,^[1] rather than inhibiting its breakdown in the liver as general MAOIs do. Additionally, isoenzyme B remains free and continues to metabolize tyramine in the stomach, although this is less significant than the liver action. Thus, a special diet does not need to be so strictly adhered to, although eating excessively large amounts of tyramine-containing foods is not advisable.

While safer than general MAOIs, RIMAs still have highly dangerous and sometimes fatal interactions with many common drugs; in particular, they can cause serotonin syndrome when combined with almost any antidepressant or stimulant (prescribed or not), common migraine medications, certain herbs, or even most cold medicines (including decongestants, antihistamines, and cough syrup).^{[citation needed]}

[edit] References

This psychoactive drug-related article is a stub. You can help Wikipedia by expanding it.

This enzyme-related article is a stub. You can help Wikipedia by expanding it.