Mirtazapine Antidepressants

Berendsen FIFI, Broekkamp CL. (1997). Indirect in vivo 5-FITlA-agonistic effects of the new antidepressant mirtazapine. Psychopharmacology (Berlin). 133(3) 275-82. 

Maris FA, Dingier E, Niehues S. 1999. High-performance liquid chromatographic assay with fluorescence detection for the routine monitoring of the antidepressant mirtazapine and its demethyl metabolite in human plasma. J Chromatogr B Biomed Sci Appl 721(2) 309-316. 

Shams M, Hiemke C, Hartter S. 2004. Therapeutic drug monitoring of the antidepressant mirtazapine and its N-demethylated metabolite in human serum. Ther Drug Monit 26(1) 78-84. 

Carbamazepine and possibly the antidepressant mirtazapine should not be coadministered with clozapine because these drugs may further increase the risk of agranulocytosis. In addition, the antidepressant bupropion should not be coprescribed with clozapine because it may increase clozapine s seizure risk. 

Serotonin-Boosting Antidepressants. The SSRIs have also been studied in the treatment of generalized social anxiety disorder, and paroxetine, sertraline, and venlafaxine are effective. Preliminary data suggests that the serotonin-boosting atypical antidepressants (mirtazapine and nefazodone) may also be helpful. Like the MAOIs, they appear to be effective at doses comparable to those used to treat depression. They may help avoidant patients to gradually increase their social interaction and become more assertive. 

Blocking the norepinephrine alpha-2 receptor can also increase norepinephrine activity. The alpha-2 receptor provides feedback to the neurons to stop releasing norepinephrine and, for that matter, serotonin. By blocking the alpha-2 receptor, norepinephrine and serotonin are more readily released. The atypical antidepressant mirtazapine (Remeron) acts in part in this manner (see Table 13.2). 

Preskorn SH. Selection of an antidepressant mirtazapine. J Clin Psychiatry 1997 58[Suppl 6] 3-8. 

In addition to its efficacy as a first-line antidepressant, mirtazapine may have enhanced efficacy due to its dual mechanism of action (Fig. 7—3), especially in combination with other antidepressants that block serotonin and/or norepinephrine reuptake. This will be discussed below in the section on antidepressant combinations. Mirtazapine may also have utility in panic disorder, generalized anxiety disorder, and other anxiety disorders, but has not been intensively studied for these indications. 

The antidepressant mirtazapine is pharmacologically similar to mianserin. It has a slightly weaker blocking action at i-adrenoceptors, and this is claimed to give it a dual mode of action, increasing the release of both noradrenaline and serotonin (1). It is claimed to have a more rapid onset of action than some SSRIs, but this may be due to its prominent sedative effect, which improves insomnia from the start of treatment. 

Unlike most other antidepressants, mirtazapine does not inhibit the reuptake of monoamines, but instead blocks inhibitory a2-adrenoceptors. It is conceivable that this pharmacological mechanism led to hypomanic symptoms in this patient. 

Antidepressants mirtazapine, nefazodone, sertraline Neuroleptics thioridazine, haloperidol, clozapine, quetiapine, risperidone, sertindole, ziprasidone Mood stabilizers carbamazepine, gabapentin, lamotrigine... 

Finally, the atypical antidepressants mirtazapine and mianserin are structural analogs of 5-HT with potent antagonistic effects at several postsynaptic 5-HT receptor types (including 5-HT, 5-HT2U and 5-HT receptors) and can produce gradual down-regulation of 5-HT receptors. Mirtazapine limits the effectiveness of inhibitory adrenergic heteroreceptors on sero-... 

Stormer E, von Moltke LL, Shader Rl, et al. Metabolism of the antidepressant mirtazapine in vitro contribution of cytochromes P-450 1A2, 2D6, and 3A4. Drug Metab Dispos 2000 28 1168-1175. 

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