Mirtazapine: Difference between revisions

Mirtazapine inhibits presynaptic serotonin (5-HT)-2 and alpha-2 adrenergic auto- and hetero-receptors, thereby increasing serotonergic and noradrenergic neurotransmission. The increased amount of 5-HT released interacts with postsynaptic 5-HT1 receptors, which may be relevant to the antidepressant effects of the drug. The affinity of mirtazapine for central alpha-2 adrenoreceptors is 10 times higher than for peripheral receptors, resulting in fewer peripheral effects related to increased blood pressure. Mirtazapine is an antagonist at postsynaptic 5-HT2A, 5-HT2C, and 5-HT3 receptors. The blockade of these receptors may result in a lower incidence of certain adverse effects (e.g., anxiety, insomnia, nausea) than occurs with antidepressants that do not antagonize these receptors. Mirtazapine significantly antagonizes histamine H1 receptors at low doses, and this activity is associated with sedation and appetite stimulation. Higher doses have a greater effect on norepinephrine release relative to antihistamine effects, which may offset the sedative potential and appetite stimulation observed at low doses. Mirtazapine has muscarinic antagonist properties, which may be associated with xerostomia, constipation, and other anticholinergic effects. Orthostatic hypotension is the result of the peripheral alpha-1 adrenergic antagonism of the drug. Mirtazapine does not have clinically significant receptor affinity for dopamine, 5-HT1A, or 5-HT1B, and has no effects on the central reuptake of either norepinephrine or serotonin.:<ref name="Fernandez2005">{{cite journal | vauthors=((Fernández, J.)), ((Alonso, J. M.)), ((Andrés, J. I.)), ((Cid, J. M.)), ((Díaz, A.)), ((Iturrino, L.)), ((Gil, P.)), ((Megens, A.)), ((Sipido, V. K.)), ((Trabanco, A. A.)) | journal=Journal of Medicinal Chemistry | title=Discovery of New Tetracyclic Tetrahydrofuran Derivatives as Potential Broad-Spectrum Psychotropic Agents | volume=48 | issue=6 | pages=1709–1712 | date=1 March 2005 | url=https://pubs.acs.org/doi/10.1021/jm049632c | issn=0022-2623 | doi=10.1021/jm049632c}}</ref><ref>{{cite journal | vauthors=((Boer, Th. de)), ((Maura, G.)), ((Raiteri, M.)), ((Vos, C. J. de)), ((Wieringa, J.)), ((Pinder, R. M.)) | journal=Neuropharmacology | title=Neurochemical and autonomic pharmacological profiles of the 6-aza-analogue of mianserin, org 3770 and its enantiomers | volume=27 | issue=4 | pages=399–408 | date=1 April 1988 | url=https://www.sciencedirect.com/science/article/pii/0028390888901499 | issn=0028-3908 | doi=10.1016/0028-3908(88)90149-9}}</ref>

*'''[[Effect::Emotion suppression]]''' - Mirtazapine can have a dulling effect on emotions and it is sometimes difficult to express them.