Meprobamate: uses and side effects of this drug

This anxiolytic and sedative psychotropic drug was developed to replace barbiturates.

The high prevalence of anxiety-related problems has led different disciplines to seek the development of different ways of dealing with them. Among them we can find pharmacology, which throughout history has been discovering and developing different substances that allow treating this type of problems.

Many of them are highly effective, although some of them and especially the first generations of anxiolytics have shown that despite this they can also cause dangerous side effects. In some cases the drug has even been recommended and even withdrawn in most parts of the world. A relatively recent case is that of meprobamate meprobamate, which we will discuss in this article..

What is meprobamate?

The name meprobamate refers to an anxiolytic or tranquilizing drugwhich, through its action on the organism, relieves anxiety and agitation. Within the anxiolytics it belongs to the group of propanediols and carbomates.

It is one of the oldest types of tranquilizers or anxiolytic drugs, born in 1950 and applied as a psychopharmaceutical since 1955. It replaced the barbiturates (with whom it shares pharmacological properties), but with the advent of benzodiazepines, it was but with the advent of benzodiazepines, its use diminished to a great to a great extent as it was replaced by benzodiazepines.

This drug has myorelaxant, hypnotic and sedative effects, and its effectiveness and half-life is between six and seventeen hours (although there may be accumulation and prolongation of this in prolonged treatments in excess), similar to that of intermediate-acting barbiturates. Its use is usually reserved for short-term treatment of anxiety, since this substance has a high addictive potential and dangerous side effects. It is metabolized in the liver and excreted by the kidneys, and comes in tablet, tablet and solution form for oral and intravenous administration.

But although it has a certain level of effectiveness, it also has a very narrow safety margin between therapeutic and toxic doses, making it relatively easy to suffer an unintentional overdose that can generate serious repercussions and even death. For this reason, and in view of the existence of much safer therapeutic alternatives, in 2012 the European Union Medicines Agency recommended its withdrawal, and today it is withdrawn in most of the world.

Mechanism of action of this psychotropic drug

Meprobamate acts in the body by modifying the functioning of the nervous system, although the way in which it does so is generally poorly understood. It is a drug that inhibits nervous system functioning and reduces neuronal activation and activity in different brain nuclei..

Thus, it is known that it acts by causing depression in the central nervous system of nuclei such as the limbic system and the thalamus (something that helps to reduce anxiety), in addition to also affecting the spinal cord (something that is related to its action as a muscle relaxant) affecting, among others, the interneurons that connect the various neurons that are part of the motor system.

What are its indications?

As a sedative-hypnotic anxiolytic, meprobamate had as main indications the short-term treatment of symptoms of anxiety and nervous agitation..

In addition to this, another of the usual indications for this drug has been the treatment of conditions related to spasticity and muscular rigidity, given that, as we have said, it has positive effects on muscle relaxation. Although it is not among its indications, it has Anticonvulsant effects, something that can help to control convulsive crises typical of different disorders.

It also had as indication the treatment of primary insomniabut in this aspect its efficacy is rather limited. Last but not least, it should be noted that it has been used for the treatment of conditions such as hypertension, since it has a strong effect in reducing it.

Side effects.

Meprobamate is a drug that may have some effectiveness, but whose consumption may have a relevant risk of generating bothersome and even dangerous side effects, to the point of having been withdrawn from many countries due to its poor safety.

Some relatively frequent side effects are sedation, fatigue, headache, dizziness and motor incoordination.. Vomiting and diarrhea are also possible, in addition to anorexia or loss of appetite. Other more serious and requiring medical attention are unexplained bleeding, problems and decreased ability to breathe and communicate, tachycardia and arrhythmias.

It should also be noted that it causes hypotension, which, although it has come to be used medically, can be problematic and dangerous depending on the sector of the population. It can also cause cognitive impairment and episodes of confusion, urticaria, angioneurotic edema, bronchospam or urination difficulties. It can also cause blood problems, including anemia, agranulocytosis, leukopenia and thrombocytopenia.

Among these side effects its addictive potential, which it shares to a large extent with barbiturates. and can lead to physical and psychological dependence on this substance and abuse, as well as withdrawal syndrome after cessation, which can cause convulsions, hallucinations, anxiety, vomiting, loss of appetite and lethargy. In case of overdose it can even cause fatal respiratory arrest or coma.

Contraindications

Although it is a withdrawn drug, it is also interesting to know which sectors of the population are particularly contraindicated, since in some cases its consumption is dangerous and the probability of suffering serious medical problems is accentuated.

In the first place, it is contraindicated for people who are allergic to this drug or its components or to drugs of the carbamate group. It is also contraindicated for those with basic arterial hypotension, as well as for those suffering from hepatic or renal insufficiency or failure. or for those suffering from porphyria (it may worsen this condition). In epileptic patients it may cause seizures.

It is contraindicated (except in case of necessity) in pregnant and lactating women, since the drug is able to cross the placenta or be transmitted through breast milk and is capable of causing abnormalities. Caution should be exercised in patients with diabetes, the elderly and children, in subjects with depression and a history of suicide attempts, as well as in people with a history of substance dependence. It should not be mixed with alcohol or other depressant substances, as well as antidepressants, muscle relaxants, anticonvulsants or narcotics among others.

Bibliographic references:

• American Society of Health-System Pharmacist (2017). Meprobamate. MedlinePlus [Online]. Available at: https://medlineplus.gov/spanish/druginfo/meds/a682077-es.html#special-dietary.
• European Medicines Agency (2012). Questions and answers on the suspension of marketing authorisations for medicinal products containing meprobamate for oral use. Outcome of a procedure under Article 107 of Directive 2001/83/EC. [Online]. Available at: https://www.ema.europa.eu/en/documents/referral/questions-answers-suspension-marketing-authorisations-oral-meprobamate-containing-medicines_es.pdf.
• García, A., Fariñas, A.T. & Gálvez, A.M. (2002). Use of meprobamate in the treatment of arterial hypertension. Economic consequences. Rev Cubana Farm v.36 n.3 Havana City.
• Stolerman, I.P. (2010). History of Psychopharmacology. Encyclopedia of Psychopharmacology. Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg.