 It is used by injection into a vein over a 60-hour period under medical supervision.Side effects of brexanolone may include sedation, sleepiness, dry mouth, hot flashes, and loss of consciousness.It is a neurosteroid and acts as a positive allosteric modulator of the GABAA receptor, the major biological target of the inhibitory neurotransmitter γ-aminobutyric acid (GABA).