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Information |
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Drug Groups
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approved |
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Description
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Mirtazapine is an antidepressant introduced by Organon International in 1996 used for the treatment of moderate to severe depression. Mirtazapine has a tetracyclic chemical structure and is classified as a noradrenergic and specific serotonergic antidepressant (NaSSA). It is the only tetracyclic antidepressant that has been approved by the Food and Drug Administration to treat depression. [Wikipedia] |
| Indication |
For the treatment of major depressive disorder. |
| Pharmacology |
Mirtazapine, an antidepressant of the piperazinoazepine class, is a tetracyclic compound with an anxiolytic effect. Mirtazapine has fewer ADRs than tricyclic antidepressants and is better tolerated. Selective blockade of specific serotonin receptors by mirtazapine likey minimizes side effects typical of other antidepressants. |
| Toxicity |
Symptoms of overdose include disorientation, drowsiness, impaired memory, and tachycardia. LD50 is 600-720mg/kg (oral, mice) and 320-490mg/kg (oral, rat) [PMID: 10333982] |
| Affected Organisms |
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Humans and other mammals |
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| Biotransformation |
Mirtazapine is extensively metabolized by demethylation and hydroxylation followed by glucuronide conjugation. Cytochrome P450 2D6 and cytochrome P450 1A2 are involved in formation of the 8-hydroxy metabolite of mirtazapine, and cytochrome P450 3A4 is responsible for the formation of the N-desmethyl and N-oxide metabolites. Several metabolites possess pharmacological activity, but plasma levels are very low. |
| Absorption |
Rapid and complete, but, due to first-pass metabolism, absolute bioavailability is 50%. |
| Half Life |
20-40 hours |
| Protein Binding |
85% |
| Elimination |
This drug is known to be substantially excreted by the kidney (75%). |
| References |
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Gillman PK: A systematic review of the serotonergic effects of mirtazapine in humans: implications for its dual action status. Hum Psychopharmacol. 2006 Mar;21(2):117-25.
[Pubmed]
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Burrows GD, Kremer CM: Mirtazapine: clinical advantages in the treatment of depression. J Clin Psychopharmacol. 1997 Apr;17 Suppl 1:34S-39S.
[Pubmed]
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Velazquez C, Carlson A, Stokes KA, Leikin JB: Relative safety of mirtazapine overdose. Vet Hum Toxicol. 2001 Dec;43(6):342-4.
[Pubmed]
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Gorman JM: Mirtazapine: clinical overview. J Clin Psychiatry. 1999;60 Suppl 17:9-13; discussion 46-8.
[Pubmed]
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Baldwin DS, Anderson IM, Nutt DJ, Bandelow B, Bond A, Davidson JR, den Boer JA, Fineberg NA, Knapp M, Scott J, Wittchen HU: Evidence-based guidelines for the pharmacological treatment of anxiety disorders: recommendations from the British Association for Psychopharmacology. J Psychopharmacol. 2005 Nov;19(6):567-96.
[Pubmed]
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[Pubmed]
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| External Links |
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