Can a neurotransmitter also be a neuromodulator? i want to know if medications that supposedly only affect one could affect multiple neurotransmitters

YOU BET IT CAN: Generally, we have both excitatory (glutamate, glycine) and inhibitory neurotransmitters (acetylcholine, norepinephrine, seratonin, dopamine). However, each transmitter affects both types of receptors, and glutamate for example is ionotrophic (NMDA, AMPA, Kainate) and metabotrophic (numerous). Simply to maintain balance & homeostasis, and adjust or modulate signals, like a computer circuit.