Nervous system depressant drugs: characteristics and examples

Drugs are substances that generate in the people who use them an effect on their mental life, which they tend to value as pleasant at the moment in which it is expressed, but that ends up severely conditioning the way in which they carry out their activities daily.

And it is that all drugs imply (in a certain way) the manipulation of our central reward system, vitiating the "magnetism" of the compass that guides our motivations and goals in life. This is how the phenomenon we know as "addiction" or "dependence" occurs.

The effects of any substance on our brain can be divided into three categories, namely: stimulant (generation of euphoria and increased activity), psychodysleptic (alteration of perception) and depressant (deep relaxation of physiological and cognitive activation).

In this article we will address precisely the last of them, highlighting several of the nervous system depressant drugs that are most frequently consumed in the world. Special attention will be given to their effects and how they alter thinking and behavior.

• Related article: "Parts of the Nervous System: functions and anatomical structures"

Nervous system depressant drugs

Central nervous system depressant drugs have the property of induce states of deep muscular relaxation, as well as laxity of consciousness and slowing down at a cognitive level and physiological processes such as breathing or heart rate. All of them have the property of exerting synergistic effects when consumed in a combined, so the concomitant use of two or more of these can lead to coma or even death. death. In addition, they have shown to be capable of generating tolerance and withdrawal syndrome (which is the opposite of the effect of intoxication).

Another aspect that must be known is that of cross-tolerance. The consumption of a drug of this family means that each time a higher dose is needed to obtain the same effect that was achieved at the beginning, but all this is extensible to all of them. Thus, if someone develops this process with alcohol, they will show an attenuated reaction to the effect of anxiolytics when they are consumed separately. Let's see from now on what these drugs are and their most important characteristics.

1. Alcohol

Alcohol is the generic name for ethanol.. It comes from the aerobic fermentation of the sugar contained in some fruits (grapes, apples, etc.) and grains (rice, barley, etc.), mediated by the activity of fungi such as yeasts. In general, it is possible to differentiate their presentation into two different categories: fermented drinks (wine, beer, etc.) and drinks distilled (whiskey, rum, gin, etc.), of which the latter contain a higher percentage of this substance (thirty degrees or further).

Alcoholic beverages are understood to be all products that contain at least 1% ethanol in their composition (or one degree, which would be an equivalent measure); and a very wide range of spirits and beers marketed as "non-alcoholic" fall into this category. The calculation of the grams of this substance would be carried out through the simple multiplication of its degrees (in each 100 cc of liquid) by 0.8, a figure that corresponds to its density.

When the substance is ingested, 80% of it is absorbed by the small intestine, and the remaining 20% ​​by the stomach. In addition to that, crosses the blood-brain and placental barriersTherefore, it would reach the brain and the fetus in the case of pregnant women (acting as a very dangerous teratogen and increasing the risk of multiple problems in the newborn).

In turn, women are intoxicated more quickly and have a higher risk of the substance harming their body. When alcohol is mixed with gas (carbonated drinks) or used on an empty stomach, the onset of its effect is accelerated.

arguably alcohol-induced drunkenness involves going through a series of well-differentiated stages. In the first place, it is possible that the person experiences well-being and a tendency to laugh easily, accompanied by talkativeness and behavioral disinhibition (by which he dares to interact with others in a less "apprehensive").

Progressively, as use continues, a state of sedation and numbness when trying to move, with slurred speech and a substantial loss of reflexes arrives. Finally, a state is reached in which consciousness is altered, lacunar amnesia and breathing difficulties develop. At this point, the risk of coma and death (from respiratory depression) is present.

Despite being a drug that can be legally acquired without any problem, and even being a common guest in many celebrations and parties, alcohol generates addiction and is associated with multiple pathologies in different organs and systems. Its use is particularly harmful in the case of women, due to intersex discrepancies in the body distribution of adipose tissue and the enzymes responsible for its metabolization.

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2. Benzodiazepines

Benzodiazepines are drugs prescribed to address some of the disorders included in the category global anxiety, and more particularly those with a profile of physiological symptoms (such as panic e.g.). They act on our brain affecting the GABA, the most important inhibitory neurotransmitter for humans, which reduces the basal level of cortical activation. Its effect begins about ten or fifteen minutes after taking it orally, through which it is easily absorbed.

Its impact on the body attenuates the way the sympathetic nervous system precipitates one's anxious physiology. That is why it is used in the treatment of this symptom, despite the fact that it can generate addiction among those who consume it for long periods. Thus, the appearance of both a withdrawal syndrome (discomfort when consumption is abandoned or when the drug is not available) has been described. of this compound) and tolerance (need to increase the dose to achieve the same effect that was obtained when start). In some cases, it also causes hostility and irritability.

When consumed in higher doses, they can induce sleep, or what is the same, acquire hypnotic properties (reducing the time between access to bed and conciliation). However, its use modifies its structure: it shortens phase 1 (light sleep), prolongs phase 2 and practically cancels phases 3 and 4 (deep sleep). It is for this very reason that It is a priority to provide sleep hygiene strategies, and reserve this drug only for cases of extreme necessity, keeping it for a maximum of three or four weeks.

In addition to its anxiolytic/hypnotic effects, this medication induces muscle relaxation through its action on the basal ganglia, the cerebellum, and the spinal cord; and anticonvulsant effects, including spasms that occur in the setting of alcohol withdrawal. That is why its use can be extended to health problems very different from anxiety, such as contractures in muscle fibers and detoxification of other substances.

Side effects of its administration include dizziness (particularly in elderly patients whose liver and/or kidney function is impaired), excessive sedation, headaches, inhibited sexual desire, erectile dysfunction, insufficient lubrication, joint involvement during language production (dysarthria/dysphasia), tremor, diarrhea or constipation. Cases of anterograde amnesia have also been detected, that is, of a hindering of the information storage process in the long-term memory store. Such problems make academic and work activities difficult, and significantly reduce the quality of life.

Despite everything, these drugs have a better safety profile than those used before them: barbiturates. Adhering to what the doctor stipulates through his clinical judgment, without increasing the dose or prolonging the treatment time, is essential to minimize the risk of addiction.

• You may be interested in: "Benzodiazepines (psychopharmaceuticals): uses, effects and risks"

3. Barbiturates

Barbiturates are nonselective depressants of the nervous system. They are made up of barbituric acid (a combination of urea and malonic acid from apples) and two carbon radicals.

Until the 1960s it was the most commonly used anxiolytic, despite being sadly famous for the high number of fatal poisonings it produced worldwide (since the therapeutic and fatal doses are excessively close). This fact, together with its enormous addictive capacity, made it necessary to discourage it from treatment and replace it with new anxiolytics (when they were synthesized).

Currently they are only used for intravenous anesthesia in certain surgeries, and also for resuscitation of head injuries. Also, as curious information, it is included (along with other substances) in the lethal injection formula, which is still used today in the US. Finally, sodium phenobarbital is still used for epilepsy, this being one of the substances that most deaths caused by respiratory depression worldwide (especially when combined with alcohol).

4. GHB

GHB (gamma-hydroxybutyrate) is another of our brain depressant drugs, which very often labeled as liquid ecstasy. What is really true is that it is a misnomer, since ecstasy (or MDMA) is a chemical compound whose effect and mechanism of action are different from those of GHB. The latter is usually presented as a transparent and slightly salty liquid, which facilitates its "camouflage" in drinks of all kinds without practically being able to the change in its flavor can be perceived, which is dangerous for those who may inadvertently take it (since it enhances the effect of alcohol and facilitates an eventual overdose).

It is a popular drug at rave parties, which traditionally took place in the underground and in which all kinds of substances were used together with electronic music and street lights. colors. GHB consumption induces a state of "euphoria" and disinhibition by depression of the prefrontal cortex, something that on many occasions ends up being expressed as acts of violence. Many of those who use it recognize hallucinations in the visual modality, so that a response of agitation and nervousness is consequently precipitated, leading to the collapse of emotions.

The effect of the substance reaches its peak approximately 10-20 minutes after consumption, which is why in the past the possibility of using it as a sleep inducer was postulated anesthetic. Later it had to be ruled out due to the perceptual alterations it caused and also due to its numerous and disabling secondary effects (dizziness, nausea, diplopia, drowsiness and headaches). The effect of the drug lasts for two hours, but with a residual stage that doubles the duration. Its origin is synthetic (it comes from artificial synthesis in a laboratory).

Sometimes its presentation is in the form of a whitish powder, which makes it easier to assess the associated effect according to the dose administered (in grams). It is estimated that after four grams it can induce a state of sleep that is tremendously difficult to interrupt, as well as a dissolution of consciousness that ultimately implies states comatose

5. kava

Kava is a substance that is sold as an alternative medicine for the treatment of acute states. of anxiety, although there is still no evidence on its possible beneficial effect in this regard. It comes from a plant of Polynesian origin (piper nigrum) directly related to the pepper tree, and which is widely used in regions that are distributed throughout the Pacific Ocean. Its effects are similar to those of other depressant substances described in this text, and include a state of calm and relaxation in which the full integrity of higher cognitive functions is maintained.

Despite the fact that there are some studies on the substance from which addictive properties are inferred, the truth is that there is still no definitive evidence on this point. It is usually presented in the form of a drink, and its active ingredients are called kavalactones. All possible harmful effects that could be attributed to this substance, including its hepatotoxicity and possible tissue apoptosis, are still under study.

6. Heroin

Heroin is one of the most addictive drugs ever documented.. It is made from morphine, which in turn is extracted from the opium poppy. It comes as a white powder, or as a sticky, blackish substance. Some of its users mix it with cocaine (speedball), from which a mixture is derived that has led to the death of many people over the last decades. In the latter case, the route of consumption is injected, although heroin is also administered via smoked and inhaled, which speeds up its access to the nervous system and the time it takes to take effect on it (by attaching to receptors opioids).

In its beginnings, this drug was synthesized in order to replace morphine for military use, since it many soldiers returned to their country (after the first great war) suffering from a harmful chemical dependency on same. It was also sold for the innocent purpose of treating the common cough and diarrhea. Finally, however, withdrawn from the market for safety reasons; although its use spread as an illegal practice unstoppably, especially in the 1960s.

Its consumption produces significant dry mouth (xerostomia), flushing, heaviness in the arms/legs, nausea, diffuse dermal itching, cognitive slowing, deep drowsiness and vomiting. When it is stopped, excruciating joint pain, flu-like symptoms, uncontrollable diarrhea, tremors, and a desperate search for the substance can occur. The effects of withdrawal symptoms can sometimes be quite severe, forcing damage control treatments to be combined with partial agonists (methadone).

As time passes, if its use is not stopped, complications of enormous importance can arise. The most relevant are damage to the structure of the nasal passages (in the case of the inhaled route), insomnia in any of its phases, pericarditis (infection of the tissue that covers the heart), alterations in the sexual sphere, chronic constipation, problems in emotional life (especially depression) and a degradation of renal and hepatic. Social ostracism is also very common, which aggravates the problem and makes it difficult for an adequate reintegration to take place..

In other cases, as a result of improper use of syringes and the utensils used for their intravenous administration, the heroin user can contract a chronic infection (HIV, hepatitis, etc.); This represents an additional health problem for which independent therapeutic solutions must be offered. Finally, there is a relevant risk of overdose, derived from the synergistic effects of its combination with other depressants, or by using it in an unusual or infrequent space (due to tolerance conditioned).

Bibliographic references:

• Barerah, S. (2018). Forms of Drug Abuse and Their Effects. Alcoholism and Drug Abuse Weekly, 1. pp. 13 - 19.
• Dassanayake, T., Michie, P., Jones, A., Carter, G., Mallard, T, and Whyte, I. (2012). Cognitive Impairment in Patients Clinically Recovered From Central Nervous System Depressant Drug Overdose. Journal of clinical psychopharmacology, 32, 503-510.