Due to their reversibility, they are safer in single-drug overdose than the older, irreversible MAOIs,[2] and weaker in increasing the monoamines important in depressive disorder.

[19] MAOIs can also be used in the treatment of Parkinson's disease by targeting MAO-B in particular (therefore affecting dopaminergic neurons), as well as providing an alternative for migraine prophylaxis.

[21][22] People taking MAOIs generally need to change their diets to limit or avoid foods and beverages containing tyramine.

[24] Examples of foods and beverages with potentially high levels of tyramine include cheese, Chianti wine, and pickled fish.

[26][28][29] The most significant risk associated with the use of MAOIs is the potential for drug interactions with over-the-counter, prescription, or illegally obtained medications, and some dietary supplements (e.g., St. John's wort or tryptophan).

For this reason, many users carry an MAOI-card, which lets emergency medical personnel know what drugs to avoid (e.g. adrenaline [epinephrine] dosage should be reduced by 75%, and duration is extended).

[30] MAOIs should not be combined with other psychoactive substances (antidepressants, painkillers, stimulants, including prescribed, OTC and illegally acquired drugs, etc.)

[citation needed] Ocular alpha-2 agonists such as brimonidine and apraclonidine are glaucoma medications which reduce intraocular pressure by decreasing aqueous production.

[38] MAOIs, as with most antidepressant medication, may not alter the course of the disorder in a significant, permanent way, so it is possible that discontinuation can return the patient to the pre-treatment state.

A few newer MAOIs, a notable one being moclobemide, are reversible, meaning that they are able to detach from the enzyme to facilitate usual catabolism of the substrate.

[41] Harmaline found in Peganum harmala, Banisteriopsis caapi, and Passiflora incarnata is a reversible inhibitor of monoamine oxidase A (RIMA).

[43] The initial popularity of the 'classic' non-selective irreversible MAO inhibitors began to wane due to their serious interactions with sympathomimetic drugs and tyramine-containing foods that could lead to dangerous hypertensive emergencies.

Further improvement occurred with the development of compounds (moclobemide and toloxatone) that not only are selective but cause reversible MAO-A inhibition and a reduction in dietary and drug interactions.

[49] A transdermal patch form of the MAOI selegiline, called Emsam, was approved for use in depression by the Food and Drug Administration in the United States on 28 February 2006.

[51] The antibiotic furazolidone also has MAO-inhibiting activity [52] Methylene blue (methylthioninium chloride), the antidote indicated for drug-induced methemoglobinemia on the World Health Organization's List of Essential Medicines, among a plethora of other off-label uses, is a highly potent, reversible MAO inhibitor.