Tag: Mianserin

What is Asenapine?

Published on by Andrew Marshall1 Comment

Introduction

Asenapine, sold under the brand name Saphris among others, is an atypical antipsychotic medication used to treat schizophrenia and acute mania associated with bipolar disorder as well as the medium to long-term management of bipolar disorder.

It was chemically derived via altering the chemical structure of the tetracyclic (atypical) antidepressant, mianserin.

It was initially approved in the United States in 2009 and approved as a generic medication in 2020.

Medical Uses

Asenapine has been approved by the FDA (US Food and Drug Administration) for the acute treatment of adults with schizophrenia and acute treatment of manic or mixed episodes associated with bipolar I disorder with or without psychotic features in adults. In Australia asenapine’s approved (and also listed on the PBS (Pharmaceutical Benefits Scheme)) indications include the following.

  • Schizophrenia
  • Treatment, for up to 6 months, of an episode of acute mania or mixed episodes associated with bipolar I disorder
  • Maintenance treatment, as monotherapy, of bipolar I disorder

In the European Union and the United Kingdom, asenapine is only licensed for use as a treatment for acute mania in bipolar I disorder.

Asenapine is absorbed readily if administered sublingually, asenapine is poorly absorbed when swallowed. A transdermal formulation of asenapine was approved in the United States in October 2019 under the brand name Secuado.

Schizophrenia

A Cochrane systematic review found that while Asenapine has some preliminary evidence that it improves positive, negative, and depressive symptoms, it does not have enough research to merit a certain recommendation of asenapine for the treatment of schizophrenia.

Bipolar Disorder

For the medium-term and long-term management and control of both depressive and manic features of bipolar disorder asenapine was found be equally effective as olanzapine, but with a substantially superior side effect profile.

In acute mania, asenapine was found to be significantly superior to placebo. As for its efficacy in the treatment of acute mania, a recent meta-analysis showed that it produces comparatively small improvements in manic symptoms in patients with acute mania and mixed episodes than most other antipsychotic drugs such as risperidone and olanzapine (with the exception of ziprasidone). Drop-out rates (in clinical trials) were also unusually high with asenapine. According to a post-hoc analysis of two 3-week clinical trials it may possess some antidepressant effects in patients with acute mania or mixed episodes.

Adverse Effects

Adverse Effect Incidence

  • Very common (>10% incidence) adverse effects include:
    • Somnolence
  • Common (1-10% incidence) adverse effects include:
    • Weight gain
    • Increased appetite
    • Extrapyramidal side effects (EPS; such as dystonia, akathisia, dyskinesia, muscle rigidity, parkinsonism)
    • Sedation
    • Dizziness
    • Dysgeusia (altered taste)
    • Oral hypoaesthesia (numbness)
    • Increased alanine aminotransferase
    • Fatigue
  • Uncommon (0.1-1% incidence) adverse effects include:
    • Hyperglycaemia — elevated blood glucose (sugar)
    • Syncope
    • Seizure
    • Dysarthria
    • sinus bradycardia
    • Bundle branch block
    • QTc interval prolongation (has a relatively low risk for causing QTc interval prolongation.[17][18])
    • sinus tachycardia
    • Orthostatic hypotension
    • Hypotension
    • Swollen tongue
    • Dysphagia (difficulty swallowing)
    • Glossodynia
    • Oral paraesthesia
  • Rare (0.01-0.1% incidence) adverse effects include:
    • Neuroleptic malignant syndrome (Combination of fever, muscle stiffness, faster breathing, sweating, reduced consciousness, and sudden change in blood pressure and heart rate)
    • Tardive dyskinesia
    • Speech disturbance
    • Rhabdomyolysis
    • Angioedema
    • Blood dyscrasias such as agranulocytosis, leukopenia and neutropenia
    • Accommodation disorder[clarification needed]
    • Pulmonary embolism
    • Gynaecomastia
    • Galactorrhoea
  • Unknown incidence adverse effects:
    • Allergic reaction
    • Restless legs syndrome
    • Nausea
    • Oral mucosal lesions (ulcerations, blistering and inflammation)
    • Salivary hypersecretion
    • Hyperprolactinaemia

Asenapine seems to have a relatively low weight gain liability for an atypical antipsychotic (which are notorious for their metabolic side effects) and a 2013 meta-analysis found significantly less weight gain (SMD [standard mean difference in weight gained in those on placebo vs. active drug]: 0.23; 95% CI: 0.07-0.39) than, paliperidone (SMD: 0.38; 95% CI: 0.27-0.48), risperidone (SMD: 0.42; 95% CI: 0.33-0.50), quetiapine (SMD: 0.43; 95% CI: 0.34-0.53), sertindole (SMD: 0.53; 95% CI: 0.38-0.68), chlorpromazine (SMD: 0.55; 95% CI: 0.34-0.76), iloperidone (SMD: 0.62; 95% CI: 0.49-0.74), clozapine (SMD: 0.65; 95% CI: 0.31-0.99), zotepine (SMD: 0.71; 95% CI: 0.47-0.96) and olanzapine (SMD: 0.74; 95% CI: 0.67-0.81) and approximately (that is, no statistically significant difference at the p=0.05 level) as much as weight gain as aripiprazole (SMD: 0.17; 95% CI: 0.05-0.28), lurasidone (SMD: 0.10; 95% CI: –0.02-0.21), amisulpride (SMD: 0.20; 95% CI: 0.05-0.35), haloperidol (SMD: 0.09; 95% CI: 0.00-0.17) and ziprasidone (SMD: 0.10; 95% CI: –0.02-0.22).

Its potential for elevating plasma prolactin levels seems relatively limited too according to this meta-analysis. This meta-analysis also found that asenapine has approximately the same odds ratio (3.28; 95% CI: 1.37-6.69) for causing sedation [compared to placebo-treated patients] as olanzapine (3.34; 95% CI: 2.46-4.50]) and haloperidol (2.76; 95% CI: 2.04-3.66) and a higher odds ratio (although not significantly) for sedation than aripiprazole (1.84; 95% CI: 1.05-3.05), paliperidone (1.40; 95% CI: 0.85-2.19) and amisulpride (1.42; 95% CI: 0.72 to 2.51) to name a few and is hence a mild-moderately sedating antipsychotic. The same meta-analysis suggested that asenapine had a relatively high risk of extrapyramidal symptoms compared to other atypical antipsychotics but a lower risk than first-generation or typical antipsychotics.

Discontinuation

For all antipsychotics, the British National Formulary recommends a gradual dose reduction when discontinuing to avoid acute withdrawal syndrome or rapid relapse. Symptoms of withdrawal commonly include nausea, vomiting, and loss of appetite. Other symptoms may include restlessness, increased sweating, and trouble sleeping. Less commonly there may be a feeling of the world spinning, numbness, or muscle pains. Symptoms generally resolve after a short period of time.

There is tentative evidence that discontinuation of antipsychotics can result in psychosis as a transient withdrawal symptom. It may also result in recurrence of the condition that is being treated. Rarely tardive dyskinesia can occur when the medication is stopped.

Pharmacology

Pharmacodynamics

Asenapine shows high affinity (pKi) for numerous receptors, including the serotonin 5-HT1A (8.6), 5-HT1B (8.4), 5-HT2A (10.2), 5-HT2B (9.8), 5-HT2C (10.5), 5-HT5A (8.8), 5-HT6 (9.5), and 5-HT7 (9.9) receptors, the adrenergic α1 (8.9), α2A (8.9), α2B (9.5), and α2C (8.9) receptors, the dopamine D1 (8.9), D2 (8.9), D3 (9.4), and D4 (9.0) receptors, and the histamine H1 (9.0) and H2 (8.2) receptors. It has much lower affinity (pKi < 5) for the muscarinic acetylcholine receptors. Asenapine behaves as a partial agonist at the 5-HT1A receptors. At all other targets asenapine is an antagonist.

Even relative to other atypical antipsychotics, asenapine has unusually high affinity for the 5-HT2A, 5-HT2C, 5-HT6, and 5-HT7 receptors, and very high affinity for the α2 and H1 receptors.

This page is based on the copyrighted Wikipedia article < https://en.wikipedia.org/wiki/Asenapine >; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA.

What is Aptazapine?

Published on by Andrew MarshallLeave a comment

Introduction

Aptazapine (developmental code name CGS-7525A) is a tetracyclic antidepressant (TeCA) that was assayed in clinical trials for the treatment of depression in the 1980s but was never marketed.

Outline

It is a potent α2-adrenergic receptor antagonist with ~10x the strength of the related compound mianserin and has also been shown to act as a 5-HT2 receptor antagonist and H1 receptor inverse agonist, while having no significant effects on the reuptake of serotonin or norepinephrine.

Based on its pharmacological profile, aptazapine may be classified as a noradrenergic and specific serotonergic antidepressant (NaSSA).

This page is based on the copyrighted Wikipedia article < https://en.wikipedia.org/wiki/Aptazapine >; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA.

What is Mianserin?

Published on by Andrew Marshall8 Comments

Introduction

Mianserin, sold under the brand name Tolvon among others, is an atypical antidepressant that is used primarily in the treatment of depression in Europe and elsewhere in the world.

It is a tetracyclic antidepressant (TeCA). Mianserin is closely related to mirtazapine, both chemically and in terms of its actions and effects, although there are significant differences between the two drugs.

Brief History

It was developed but not discovered by Organon International; the first patents were issued in The Netherlands in 1967, and it was launched in France in 1979 under the brand name Athymil, and soon thereafter in the UK as Norval. Investigators conducting clinical trials in the US submitted fraudulent data, and it was never approved in the US.

Mianserin was one of the first antidepressants to reach the UK market that was less dangerous than the tricyclic antidepressants in overdose; as of 2012 it was not prescribed much in the UK.

Medical Uses

Mianserin at higher doses (30–90mg/day) is used for the treatment of major depressive disorder.

It can also be used at lower doses (around 10mg/day) to treat insomnia.

Contraindications

It should not be given, except if based on clinical need and under strict medical supervision, to people younger than 18 years old, as it can increase the risk of suicide attempts and suicidal thinking, and it can increase aggressiveness.

While there is no evidence that it can harm a foetus from animal models, there are no data showing it safe for pregnant women to take.

People with severe liver disease should not take mianserin, and it should be used with caution for people with epilepsy or who are at risk for seizures, as it can lower the threshold for seizures. If based on clinical decision, normal precautions should be exercised and the dosages of mianserin and any concurrent therapy kept under review and adjusted as needed.

Side Effects

Very common (incidence > 10%) adverse effects include constipation, dry mouth, and drowsiness at the beginning of treatment.

Common (1% < incidence ≤ 10%) adverse effects include drowsiness during maintenance therapy, tremor, headache, dizziness, vertigo, and weakness.

Uncommon (0.1% < incidence ≤ 1%) adverse effects include weight gain.

Withdrawal

Abrupt or rapid discontinuation of mianserin may provoke a withdrawal, the effects of which may include depression, anxiety, panic attacks, decreased appetite or anorexia, insomnia, diarrhoea, nausea and vomiting, and flu-like symptoms, such as allergies or pruritus, among others.

Overdose

Overdose of mianserin is known to produce sedation, coma, hypotension or hypertension, tachycardia, and QT interval prolongation.

Interactions

Mianserin may enhance the sedative effects of drugs such as alcohol, anxiolytics, hypnotics, or antipsychotics when co-administered. It may decrease the efficacy of antiepileptic medications.

Carbamazepine and phenobarbital will cause the body to metabolise mianserin faster and may reduce its effects. There is a risk of dangerously low blood pressure if people take mianserin along with diazoxide, hydralazine, or nitroprusside. Mianserin can make antihistamines and antimuscarinics have stronger effects. Mianserin should not be taken with apraclonidine, brimonidine, sibutramine, or the combination drug of artemether with lumefantrine.

Pharmacology

Pharmacodynamics

Mianserin appears to exert its effects via antagonism of histamine and serotonin receptors, and inhibition of norepinephrine reuptake. More specifically, it is an antagonist/inverse agonist at most or all sites of the histamine H1 receptor, serotonin 5-HT1D, 5-HT1F, 5-HT2A, 5-HT2B, 5-HT2C, 5-HT3, 5-HT6, and 5-HT7 receptors, and adrenergic α1- and α2-adrenergic receptors, and additionally a norepinephrine reuptake inhibitor. As an H1 receptor inverse agonist with high affinity, mianserin has strong antihistamine effects (e.g., sedation). Conversely, it has low affinity for the muscarinic acetylcholine receptors, and hence lacks anticholinergic properties. Mianserin has been found to be a low affinity but potentially significant partial agonist of the κ-opioid receptor (Ki = 1.7 μM; EC50 = 0.53 μM), similarly to some tricyclic antidepressants (TCAs).

Blockade of the H1 and possibly α1-adrenergic receptors has sedative effects, and also antagonism of the 5-HT2A and α1-adrenergic receptors inhibits activation of intracellular phospholipase C (PLC), which seems to be a common target for several different classes of antidepressants. By antagonising the somatodendritic and presynaptic α2-adrenergic receptors, which function predominantly as inhibitory autoreceptors and heteroreceptors, mianserin disinhibits the release of norepinephrine, dopamine, serotonin, and acetylcholine in various areas of the brain and body.

Along with mirtazapine, although to a lesser extent in comparison, mianserin has sometimes been described as a noradrenergic and specific serotonergic antidepressant (NaSSA). However, the actual evidence in support of this label has been regarded as poor.

Pharmacokinetics

The bioavailability of mianserin is 20 to 30%. Its plasma protein binding is 95%. Mianserin is metabolised in the liver by the CYP2D6 enzyme via N-oxidation and N-demethylation. Its elimination half-life is 21 to 61 hours. The drug is excreted 4 to 7% in the urine and 14 to 28% in faeces.

Chemistry

Mianserin is a tetracyclic piperazinoazepine. Mirtazapine was developed by the same team of organic chemists and differs via addition of a nitrogen atom in one of the rings. (S)-(+)-Mianserin is approximately 200–300 times more active than its enantiomer (R)-(−)-mianserin; hence, the activity of mianserin lies in the (S)-(+) isomer.

Society and Culture

Generic Names

Mianserin is the English and German generic name of the drug and its INN and BAN, while mianserin hydrochloride is its USAN, BANM, and JAN. Its generic name in French and its DCF are miansérine, in Spanish and Italian and its DCIT are mianserina, and in Latin is mianserinum.

Brand Names

Mianserin is marketed in many countries mainly under the brand name Tolvon. It is also available throughout the world under a variety of other brand names including Athymil, Bonserin, Bolvidon, Deprevon, Lantanon, Lerivon, Lumin, Miansan, Serelan, Tetramide, and Tolvin among others.

Availability

Mianserin is not approved for use in the United States, but is available in the United Kingdom and other European countries. A mianserin generic drug received TGA approval in May 1996 and is available in Australia.

Research

The use of mianserin to help people with schizophrenia who are being treated with antipsychotics has been studied in clinical trials; the outcome is unclear.

This page is based on the copyrighted Wikipedia article < https://en.wikipedia.org/wiki/Mianserin >; it is used under the Creative Commons Attribution-ShareAlike 3.0 Unported License (CC-BY-SA). You may redistribute it, verbatim or modified, providing that you comply with the terms of the CC-BY-SA.