Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical trial development programme of mirtazapine (Org 3770), performed in Europe and the United States, demonstrated an outstanding safety profile of this compound. The evaluation of the safety was based on data from all patients who took at least one dose of study medication during studies comparing mirtazapine with placebo, amitriptyline or other active comparators. A general indication of mirtazapine's safety is the significantly lower percentage of patients (65%) who complained of any adverse clinical experiences compared with the placebo- (76%) or amitriptyline-treated group (87%). Moreover, drop-out rates due to adverse clinical experiences were significantly lower than in the amitriptyline-treatment group. Mirtazapine has virtually no anticholinergic, adrenergic or typical selective serotonin reuptake inhibitor (SSRI) side effects. The only significantly higher incidences versus placebo were seen in the adverse clinical effects of drowsiness (23% versus 14%), excessive sedation (19% versus 5%), dry mouth (25% versus 16%), increased appetite (11% versus 2%) and weight increase (10% versus 1%). These complaints were typically mild and transient in nature, and decreased over time despite increased doses of mirtazapine. In contrast, significantly higher incidences of headache (5% versus 10%) and weight decrease (2% versus 6%), symptoms commonly seen in depressed patients, were recorded in the placebo-treated patients. Also, typical SSRI adverse events, such as nausea, vomiting, diarrhoea and insomnia, and symptoms of sexual dysfunction were registered less frequently in mirtazapine-treated patients than in the placebo-treated patients. Approximately 10% of the mirtazapine-treated patients in the clinical trial programme were older than 65 years. The pattern of adverse clinical experiences seen in this group of patients is fully in line with that seen in the overall patient population. The analysis of vital sign indices, i.e. blood pressure and heart rate, showed that no changes occurred with mirtazapine treatment; this pattern was fully comparable to that seen with placebo. Furthermore, very low incidences of clinically relevant changes in laboratory indices, such as the liver enzymes alanine aminotransferase and aspartate aminotransferase or neutropenia, were recorded in each treatment group. Mirtazapine has a very low seizure-inducing potential: only one case was recorded in a patient with a history of seizures during previous treatment with clomipramine. The low seizure-inducing potential combined with a lack of cardiotoxic properties allows safety in an overdose of mirtazapine, even in elderly patients. The only symptom seen in the patients taking an overdose of mirtazapine alone or in combination with other drugs was excessive but transient somnolence, which resolved spontaneously within a few hours. In conclusion, the new antidepressant mirtazapine offers clinicians a unique combination of strong efficacy and good safety.
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PMID:Safety of mirtazapine: a review. 893 8

Mirtazapine is the first of a new class of antidepressants, the noradrenergic and specific serotonergic antidepressants (NaSSA). Its antidepressant effect appears to be related to its dual enhancement of central noradrenergic and serotonin 5-HT1 receptor-mediated serotonergic neurotransmission. Mirtazapine possesses a number of useful pharmacokinetic characteristics such as good absorption, linear pharmacokinetics over the recommended dosage range (15 to 80 mg/day), and an elimination half-life of 20 to 40 hours, thereby allowing once-daily administration. However, since the drug is extensively metabolised by the hepatic cytochrome P450 (CYP) system and is excreted mainly in the urine, its clearance may be reduced by hepatic or renal impairment. In vitro data suggest that from a clinical point of view it is unlikely that mirtazapine would inhibit the metabolism of coadministered drugs metabolised by CYP1A2, CYP2D6 or CYP3A4. In vivo data from a study in extensive and poor metabolisers of debrisoquine indicate that strong inhibitors of CYP2D6 would have no effect on the concentration of racemic mirtazapine. In some placebo-controlled studies mirtazapine showed an early onset of antidepressant action, with significant reductions in total Hamilton Depression Rating Scale and Montgomery-Asberg Depression Rating Scale scores (relative to placebo) noted as early as 1 week after starting treatment. This therapeutic advantage was subsequently maintained during treatment, with mirtazapine proving significantly superior to placebo at treatment end-point in the majority of studies. In comparative trials, the antidepressant efficacy of mirtazapine was comparable with that of tricyclic antidepressants such as amitriptyline, clomipramine and doxepin, and in 2 studies superior to that of trazodone and fluoxetine. Mirtazapine appears to have a broad spectrum of activity, reflected in its efficacy in a variety of clinical settings. Its additional beneficial effects on the symptoms of anxiety and sleep disturbance associated with depression may reduce the need for concomitant anxiolytic and hypnotic medication seen with some antidepressants. Mirtazapine has demonstrated superior tolerability to the tricyclic antidepressants and trazodone, primarily on account of its relative absence of anticholinergic, adrenergic and serotonin-related adverse effects, in particular gastrointestinal adverse effects and sexual dysfunction. It appears that increased sedation associated with the drug is related to subtherapeutic dosages, and that it is reported in substantially fewer patients when the drug is used in appropriate dosages (> or = 15 mg as a single evening dose) from the beginning of treatment. Although 2 cases of reversible severe symptomatic neutropenia have been reported in clinical trials, there have been no additional reports of symptomatic neutropenia since the introduction of this drug to various countries in September 1994. Currently available data and initial clinical experience suggest that with its combination of dual action, simple pharmacokinetics, and clinical efficacy and tolerability, mirtazapine appears to be an important advance in the pharmacotherapy of depression.
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PMID:A risk-benefit assessment of mirtazapine in the treatment of depression. 935 61