ISRN: Effects And Functioning Of This Type Of Antidepressant Drug
Fourth-generation antidepressants, which act specifically on certain neurotransmitters to prevent adverse reactions as much as possible, are being prescribed with increasing frequency. However, they are still not as popular as SSRIs, which dominate the field of drug therapy for depression.
In this article we will analyze the effectiveness of selective norepinephrine reuptake inhibitors or SNRIs, which are part of this group of novel medications. We will focus primarily on reboxetine, the only SNRI that has been studied in some depth, and its comparison with other types of antidepressants.
In 1952, the first antidepressant drug in history was discovered: iproniazid, which had been developed to treat tuberculosis but turned out to be effective in improving mood. Iproniazid belonged to the pharmacological class of monoamine oxidase enzyme inhibitors (MAOIs), very powerful and dangerous for general health.
Later, tricyclic antidepressants such as imipramine appeared, clomipramine and nortriptyline. In this case the origin was research into the medical treatment of psychoses. These in turn were displaced by selective serotonin reuptake inhibitors, better known by the abbreviation “SSRIs.”
In recent years, a series of depression medications have appeared that have been attributed to be safer than SSRIs; We are talking about fourth-generation antidepressants, which include selective norepinephrine reuptake inhibitors (SNRIs) and dual serotonin and norepinephrine reuptake inhibitors (SNRIs).
Unlike tricyclics and MAOIs, Fourth generation antidepressants have a high selectivity index ; This means that they act specifically on one or more neurotransmitters, which should theoretically reduce the risk of side effects. In this sense, the new antidepressants are similar to SSRIs.
SNRIs are a class of psychotropic drugs with antidepressant effects that act specifically on one of the fundamental neurotransmitters of the nervous system: norepinephrine. This chemical compound is involved in a broad set of physiological and cognitive responses related to arousal.
Thus, norepinephrine influences stress responses (both at a physiological and cognitive level), mood, motivation, maintenance of consciousness and alertness, blood circulation, and the management of attentional resources, in aggressive behavior, in sexual pleasure and in orgasm.
As their name suggests, ISRNs They exert their action through the inhibition of norepinephrine reuptake This means that, when consuming one of these drugs, presynaptic neurons have greater difficulty absorbing norepinephrine from the synaptic space, increasing the amount that is available for neurotransmission.
Selective norepinephrine reuptake inhibitors are also called simply by the abbreviation “SRI”; In this case the term “selective” is ignored. The best known of these drugs is reboxetine which is marketed under the names “Irenor”, “Norebox”, “Prolift”, “Edronax” and “Vestra”, among others.
There are, however, other medications that can be categorized within this pharmacological class. Among these we find atomoxetine, talopram, talsupram, nisoxetine, viloxazine, amedalin, lortalamine, tandamine, daledalin, edivoxetine or esreboxetine.
The effectiveness of reboxetine
Currently, and partly as a consequence of the recent nature of their appearance, the research available on selective norepinephrine reuptake inhibitors is relatively scarce. That is why The degree of effectiveness of this type of drugs is not entirely clear and we also found very contradictory findings.
The meta-analysis by Eyding’s team (2010) evaluated the effectiveness of reboxetine for the treatment of major depression using 13 studies with more than 4 thousand patients as a starting point. These authors found no significant differences between placebo and reboxetine in symptom remission and concluded that SSRIs are more effective than SNRIs
In contrast, the UK government’s Medicines and Healthcare products Regulatory Agency (MHRA) analyzed 11 studies on the effectiveness of reboxetine and found that it was effective in severe cases of depression. They also denied that it had a greater potential to cause side effects than the placebo, as Eyding’s team proposed.
Currently available data suggest that SNRIs may have a somewhat less severe side effect profile than SSRIs, the most widely used antidepressants; However, its power is probably lower. Both classes of drug seem more effective in severe cases than in mild or moderate cases In any case, more research is required.
