What is "monoaminergic"

a. (context anatomy of nerve cells English) That transmit impulses by employing the monoamine neurotransmitters catecholamine or indolamine

Monoaminergic means "working on monoamine neurotransmitters", which include serotonin, dopamine, and norepinephrine (and epinephrine), as well as melatonin.

A monoaminergic, or monoaminergic drug, is a chemical which functions to directly modulate the serotonin, dopamine, norepinephrine/epinephrine, and/or melatonin neurotransmitter systems in the body or brain. Monoaminergics include catecholaminergics (which can be further divided into adrenergics and dopaminergics), serotonergics, and melatonergics. A specific example are monoamine oxidase inhibitors (MAOIs), which affect the activity of all four of these systems.