Monoamine oxidase inhibitors, or MAOIs, are types of antidepressants that inhibit the monoamine oxidase enzyme, preventing the breakdown of dopamine, norepinephrine and serotonin neurotransmitters in the brain, reports MedicineNet. Experts believe that this action improves brain cell communication, boosting mood, explains Mayo Clinic. They relieve depression and treat Parkinson's disease.
Monoamine oxidase inhibitors were the first antidepressants developed, but other antidepressants safer to use have replaced them, notes Mayo Clinic. Examples of MAOIs include phenelzine, isocarboxazid, tranylcypromine and rasagiline, according to MedicineNet. Patients should avoid combining MAOIs with antidepressants such as fluoxetine, bupropion, paroxetine and nortriptyline, as this action can raise serotonin levels, causing high blood pressure, confusion, coma or even death.
Side effects of monoamine oxidase inhibitors include orthostatic hypotension, weakness, dizziness and drowsiness, claims MedicineNet. Headache, fatigue, agitation, anxiety and weight gain are also side effects of MAOIs.