How Antidepressants Work, but Often Do Not
Scott Mendelson in Herbal Treatment of Major Depression, 2019
The monoamine oxidase inhibitors (MAOI) antidepressants were almost abandoned because of the so-called “cheese effect.” With the apparent success of iproniazid as an antidepressant, it was marketed in 1958 as the drug Marsilid. However, it was withdrawn in 1961 after it was found to cause severe liver damage in some individuals. In the case of the MAOIs, it was assumed that the increases in concentrations of monoamine neurotransmitters in the brain were responsible for their antidepressant effects. The tricyclic antidepressants (TCAs) were also thought to work by increasing the availability of monoamines in the brain. However, they did so by a different mechanism than the MAOIs. The discovery of the MAOIs and TCAs not only provided some of the first medicinal treatments for depression, but also seemed to provide insight into the nature and cause of the illness. The TCAs act primarily as blockers of those reuptake sites for serotonin and norepinephrine.
Conscious Sedation
Rahul Jandial, Danielle D. Jandial in Code Blue, 2014
This chapter provides information for performing conscious sedation. It begins with a case scenario of a 23-year-old man, who is presents with a dislocated shoulder. The chapter then includes details on indications, contraindications, and information about supplies and technique. Pearls and pitfalls are also incorporated, providing additional insights and practical advice not always available in other textbooks or articles." Morphine and fentanyl act similarly, but fentanyl may have a reduced incidence of bronchospasm. Meperidine cannot be used in patients taking monoamine oxidase inhibitors. Also, avoid using in patients with compromised renal function.
Tips for clinical practice
Alan Weiss in The Electroconvulsive Therapy Workbook, 2018
Medications taken by a patient should be reviewed before a course of Electroconvulsive Therapy (ECT) commences to prevent potential adverse effects, interactions with the seizure and seizure threshold and prolonged recovery. ECT provides an opportunity to change antidepressant medication. The relapse rate after a course of ECT is very high, making it essential to commence a new combination of pharmacotherapy to ensure remission is maintained over the next six months after the index course of ECT has been completed. Monoamine oxidase inhibitors (MAOI) antidepressant drugs eliminate the action of the enzyme monoamine oxidase in a permanent or reversible manner, leading to a secondary increase in neurotransmitters serotonin and noradrenaline. Acetylcholinesterase inhibitors are being used more commonly in patients with early onset dementia, a group of patients who are presenting more commonly for ECT. For antiepileptic mood-stabilising drugs, leave the decision to the individual treating team as maintaining, reducing or ceasing are all common practice.
Recent advances in Parkinson’s disease therapy: use of monoamine oxidase inhibitors
Published in Expert Review of Neurotherapeutics, 2005
Claire Henchcliffe, H Christian Schumacher, F Tuna Burgut
Monoamine oxidase inhibitors inhibit dopamine metabolism and are therefore effective in treating Parkinson’s disease, a condition associated with progressive striatal dopamine deficiency secondary to degeneration of dopaminergic neurons in the substantia nigra. Selegiline is currently the most widely used monoamine oxidase-B inhibitor for Parkinson’s disease, but has a low and variable bioavailability, and is metabolized to L-methamphetamine and L-amphetamine that carry a risk for potential neurotoxicity. There are two new approaches that circumvent these potential disadvantages. First, selegiline orally disintegrating tablets provide a novel delivery form of selegiline, avoiding first pass metabolism by rapid absorption through the oral mucosa, thus leading to significantly lower plasma concentrations of L-metamphetamine and L-amphetamine. Selegiline orally disintegrating tablets prove to be clinically effective and safe in patients with moderately advanced Parkinson’s disease. Second, rasagiline is a new monoamine oxidase inhibitor, without known neurotoxic metabolites. In large clinical trials, rasagiline proves effective as monotherapy in early Parkinson’s disease, as well as adjunctive therapy to levodopa in advanced disease. Clinical data suggest, in addition, a disease-modifying effect of rasagiline that may correlate with neuroprotective activity of monoamine oxidase-B inhibitors in animal models of Parkinson’s disease.
Monoamine Oxidase Inhibitors and Neuroprotective Mechanisms
Published in Klinik Psikofarmakoloji Bülteni-Bulletin of Clinical Psychopharmacology, 2012
Glen B. Baker, Dmitriy Matveychuk, Erin M. MacKenzie, Serdar M. Dursun, Darrell D. Mousseau
There has been a resurgence of interest in recent years in monoamine oxidase inhibitors, primarily because of the demonstrated neuroprotective and/or neurorescue properties of several of these drugs in a variety of toxic situations in vivo and in vitro. The consequence has been an increased interest in possible neuroprotective effects of psychiatric drugs in general, an improved understanding of glia-neuron interactions, and the provision of important clues to development of future drugs for treating psychiatric and neurological disorders. A brief overview of some relevant studies in this area is provided in this editorial.
The pharmacology of anxiolytics
Published in South African Family Practice, 2010
Given that anxiety disorders are common and chronic and often co-morbid with both medical and psychiatric conditions, effective and safe anxiolytic drugs are in great demand. Serotonergic agents, in particular the selective serotonin reuptake inhibitors and serotonin and noradrenaline reuptake inhibitors, have an established track record for the pharmacological treatment of a wide range of anxiety disorders. Despite their slow onset of therapeutic action, their initial exacerbation of anxiety and some of their long-term unwanted effects, they remain the drugs of first choice in primary care. They are relatively safe and exhibit both anxiolytic and antidepressant effects. Other antidepressants, such as mirtazapine, reboxetine and agomelatine, and the 5-HT1A agonist, buspirone, are alternative agents, although the evidence of their efficacy covers a narrower spectrum of anxiety disorders. Patients with anxiety disorders who are resistant to these drugs may benefit from second-line (tricyclic antidepressants or monoamine oxidase inhibitors) or even specialist initiated third-line (benzodiazepine, anticonvulsant or antipsychotic) therapy. None of the currently available drugs are ideal for every patient and the advantages and disadvantages of each are best considered when treatment is individualised.
Related Knowledge Centers
- Enzyme Inhibitors
- Parkinson's Disease
- Tricyclic Antidepressant
- Selegiline
- Bulimia
- Trichotillomania
- Dopamine