Antidepressants reuptake inhibitors

SSRIs are well tolerated. Adverse effects for compounds in this class include nervousness, tremor, dizziness, headache, insomnia, sexual dysfunction, nausea, and diarrhea. In addition, the tricycHc antidepressant clomipramine (33), which is a potent nonselective serotonin reuptake inhibitor, is approved for treatment of obsessive—compulsive disorder. 

Treatment of Major Depression. Dmgs commonly used for the treatment of depressive disorders can be classified heuristicaHy iato two main categories first-generation antidepressants with the tricycHc antidepressants (TCAs) and the irreversible, nonselective monoamine—oxidase (MAO) inhibitors, and second-generation antidepressants with the atypical antidepressants, the reversible inhibitors of monoamine—oxidase A (RIMAs), and the selective serotonin reuptake inhibitors (SSRIs). Table 4 fists the available antidepressants. 

Antidepressants are used in the treatment of neuropathic pain and headache. They include the classic tricyclic compounds and are divided into nonselective nor-adrenaline/5-HT reuptake inhibitors (e.g., amitriptyline, imipramine, clomipramine, venlafaxine), preferential noradrenaline reuptake inhibitors (e.g., desipramine, nortriptyline) and selective 5-HT reuptake inhibitors (e.g., citalopram, paroxetine, fluoxetine). The reuptake block leads to a stimulation of endogenous monoaminer-gic pain inhibition in the spinal cord and brain. In addition, tricyclics have NMDA receptor antagonist, endogenous opioid enhancing, Na+ channel blocking, and K+ channel opening effects which can suppress peripheral and central sensitization. Block of cardiac ion channels by tricyclics can lead to life-threatening arrhythmias. The selective 5-HT transporter inhibitors have a different side effect profile and are safer in cases of overdose [3]. 

Non-selective monoamine reuptake inhibitors (NSMRI) are a group of antidepressants, which function by inhibiting the reuptake of noradrenaline... 

Noradrenaline transporters (NAT) are localized in the presynaptic plasma membrane of adrenergic nerve terminals. They belong to a family of proteins with 12 putative transmembrane proteins which are responsible for recycling of released neurotransmitters (noradrena-line/adrenaline, dopamine, serotonin, amino acid transmitters) back into the presynaptic nerve ending. Noradrenaline transporters can be blocked by a number of different antidepressant drags, including tricyclic antidepressants (e.g. desipramine) and selective noradrenaline reuptake inhibitors (e.g. reboxetine). 

Selective noradrenaline reuptake inhibitors (SNRIs) are a group of drugs, which act as antidepressants by the selective inhibition of the reuptake of noradrenaline from the synaptic cleft via the selective blockade of the noradrenaline-specific neurontransmitter transporter (e.g. reboxetine). 

Selective serotonine reuptake inhibitor (SSRI) is an abbreviation for the class of antidepressants known as the Selective Serotonin Reuptake Inhibitors. Examples of SSRIs include fluoxetine, paroxetine, citalopram, and sertraline. These drugs selectively inhibit the serotonin transporter thus prolonging the synaptic lifespan of the neurotransmitter serotonin. 

Antidepressants Trazodone, mirtazapine, paroxetine, other selective serotonin reuptake inhibitors venlafaxine... 

Briggs G, Freeman R, Yaffe S Drugs in Pregnancy and Lactation A Reference Guide to Maternal and Fetal Risk. Philadelphia, Lippincott, Williams Wilkins, 2002 Chengappa KN, Kambhampati R, Perkins K, et al Bupropion sustained release as a smoking cessation treatment in remitted depressed patients maintained on neatment with selective serotonin reuptake inhibitor antidepressants. J Clin Psychiatry 62 503—508, 2001... 

The main focus of pharmacoeconomic studies of antidepressants has inevitably fallen on comparisons between tricyclic antidepressants (TCAs) and the more expensive selective serotonin reuptake inhibitors (SSRIs). Few data are available for comparisons within the SSRIs or for newer antidepressants. 

Anderson IM, Tomenson BM (1994). The efficacy of selective serotonin reuptake inhibitors in depression a meta-analysis of studies against tricyclic antidepressants. / Psychopharmacol 8, 238 9. 

Selective serotonin reuptake inhibitor antidepressant selection and anxiolytic and sedative hypnotic prescribing a multivariate analysis./ Clin Outcomes Manage 4, 16—22. 

There is, however, a unique risk in the bipolar form that antidepressant treatment may trigger a switch into mania. This may occur either as the natural outcome of recovery from depression or as a pharmacological effect of the drug. Particular antidepressants (the selective serotonin reuptake inhibitors) seem less liable to induce the switch into mania than other antidepressants or electroconvulsive therapy. Treatment for mania consists initially of antipsychotic medication, for instance the widely used haloperidol, often combined with other less specific sedative medication such as the benzodiazepines (lorazepam intramuscularly or diazepam orally). The manic state will usually begin to subside within hours and this improvement develops further over the next 2 weeks. If the patient remains disturbed with manic symptoms, additional treatment with a mood stabilizer may help. 

Figure 20.1 Schematic diagram illustrating how antidepressants increase the concentration of extraneuronal neurotransmitter (noradrenaline and/or 5-HT). In the absence of drug (b), monoamine oxidase on the outer membrane of mitochondria metabolises cytoplasmic neurotransmitter and limits its concentration. Also, transmitter released by exocytosis is sequestered from the extracellular space by the membrane-bound transporters which limit the concentration of extraneuronal transmitter. In the presence of a MAO inhibitor (a), the concentration of cytoplasmic transmitter increases, causing a secondary increase in the vesicular pool of transmitter (illustrated by the increase in the size of the vesicle core). As a consequence, exocytotic release of transmitter is increased. Blocking the inhibitory presynaptic autoreceptors would also increase transmitter release, as shown by the absence of this receptor in the figure. In the presence of a neuronal reuptake inhibitor (c), the membrane-bound transporter is inactivated and the clearance of transmitter from the synapse is diminished...

Opioids, benzodiazepines, barbiturates, corticosteroids, dopamine agonists (e.g., amantadine, bromocriptine, levodopa, pergolide, pramipexole, ropinirole), H2-receptor antagonists, anticholinergics (e.g., diphenhydramine, trihexylphenidyl), P-adrenergic blockers, clonidine, methyldopa, carbamazepine, phenytoin, baclofen, cyclobenzaprine, lithium, antidepressants (e.g., tricyclic antidepressants, selective serotonin reuptake inhibitors), and interleukin-2... 

Antipsychotics, bromocriptine, carbamazepine, chlorpropamide, cyclophosphamide, desmopressin, ecstasy, lamotrigine, monamine oxidase inhibitors, NSAIDs, oxcarbazepine, oxytocin, tricyclic antidepressants, selective serotonin reuptake inhibitors, vasopressin, vinblastine, and vincristine... 

FIGURE 30-2. Pain algorithm. AED, antiepileptic drug APAP, acetaminophen NSAID, non-steroidal antiinflammatory drug SNRI, serotonin-norepinephrine reuptake inhibitor SSRI, selective serotonin reuptake inhibitor TCA, tricyclic antidepressant. 

MAOI, monoamine oxidase inhibitor SSRI, selective serotonin reuptake inhibitor TCA, tricyclic antidepressant. 

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