Barbiturate drugs

Content

Introduction

Barbiturates constitute a class of drugs capable of depressing the central nervous system and may have calming (sedative) hypnotic, anticonvulsant (against convulsions) or anesthetic activity depending on the type, dose and route of administration chosen.

Today the use of barbiturates is no longer recommended, except for some types of treatment, and has been replaced by the use of safer and more effective drugs, such as benzodiazepines which, especially in case of overdose, are less dangerous and more high reliability.

Today, barbiturates are used above all as anticonvulsants in the treatment of epilepsy, in particular, in tonic-clonic seizures of the big bad (form of epilepsy), in focal cortical seizures and in conditions that require long-lasting sedation. Barbiturates are also used as sole anesthetics for short surgical procedures or in the induction of anesthesia prior to the administration of anesthetics.

Prolonged consumption of barbiturates can induce physical, psychological or both dependence and cause the appearance of a state of tolerance of the organism which makes them less and less effective. Therefore, their use for the treatment of anxiety or tension is not recommended. caused by the stress of everyday life.In addition, abrupt discontinuation of treatment in people who have taken them for a long time should be avoided. The sudden interruption in epileptic people, in fact, can induce a crisis. In any case, these are drugs whose availability and intake must be strictly bound to the doctor's prescription.

Features and uses

Barbiturates were used until the middle of the last century for their calming-hypnotic characteristics and have now been replaced by benzodiazepines in the treatment of anxiety and insomnia, since they are less dangerous in case of overdose. Despite this, barbiturates are still used in the treatment of epilepsy and in the induction of anesthesia.

They can be taken orally (by mouth), intramuscular and intravenous, depending on the therapeutic indication. Phenobarbital in oral and intramuscular administration, for example, is mainly indicated as a general sedative (sedative), with particular regard to epilepsy. and to all conditions that require long-lasting sedation, in the treatment of tonic-clonic seizures of big bad (form of epilepsy) and in focal cortical convulsions. Administered intravenously, on the other hand, it is used as a second choice emergency treatment of epilepsy, in cases where oral administration is not possible, or in people who have not found benefit from treatment with benzodiazepines and phenytoin.

Barbiturates, based on the duration of action, are classified into four categories:

  • ultra-short duration of action (About 20 minutes), such as thiopental
  • short duration of action (3-4 hours), such as pentobarbital and secobarbital
  • intermediate duration of action (4-6 hours), such as amobarbital and butabarbital
  • prolonged action (6-12 hours), such as primidone and phenobarbital

Ultra-short acting barbiturates, administered intravenously, are used to induce narcosis and, therefore, for short surgical procedures or in the induction of anesthesia prior to the administration of anesthetics. Short-acting or intermediate-acting barbiturates are primarily used as sedatives and hypnotics. Finally, long-acting barbiturates are used as anticonvulsants; in particular, in the treatment of tonic-clonic seizures of the big bad epileptic and focal cortical seizures.

As these are drugs that cause both physical and psychological addiction and dependence, their use must only take place upon prescription and under close medical supervision, absolutely avoiding modifying the doses or prolonging their use for longer periods than those prescribed.

In case of taking it for the treatment of epilepsy and for the control of convulsions, it is necessary to respect the established doses daily and regularly, in order to maintain a constant quantity of the drug in the blood. For prolonged treatments, close control is required. of the doctor to check the progress made in the evolution of the disease and, if necessary, gradually reduce the doses before completely stopping the therapy. An abrupt interruption, in fact, can cause the seizures to resume.

Side effects

The use of barbiturates can give rise to a series of undesirable effects (side effects) that must be kept in mind and communicated to your doctor. Among the main side effects we can mention:

  • bleeding of the lips
  • chest pain
  • fever
  • muscle or joint pain
  • red, thickened, or scaly skin
  • rash or hives
  • sores, ulcers, or white patches in the mouth (painful)
  • sore throat
  • swelling of the eyelids, face or lips
  • wheezing or tightness in the chest
  • state of confusion
  • mental depression
  • unusual excitement

More rarely you can have:

  • hallucinations (see or hear things that are not there)
  • unusual bleeding or bruising
  • unusual tiredness or weakness

With prolonged use, you may have:

  • bone pain, widespread aches or pains
  • loss of appetite
  • muscle weakness
  • unusual weight loss
  • yellowing of eyes or skin

When given in very low doses, barbiturates can produce paradoxical effects, such as hyperexcitation and agitation.

Barbiturate intoxication, whether voluntary or accidental, is a serious danger to life since the difference between the usual therapeutic dose and the fatal dose is minimal. The disorders (symptoms) that can occur following an overdose from barbiturates, are:

  • severe confusional states
  • decrease or loss of reflexes
  • severe forms of drowsiness
  • fever
  • continuous irritability
  • low body temperature
  • shortness of breath or slow or labored breathing
  • slow heartbeat
  • slurred speech and confused language
  • severe forms of insomnia
  • unusual eye movements
  • excessive weakness

In more severe barbiturate intoxications, the following may also arise:

  • circulatory failure
  • respiratory depression
  • coma
  • death

It should be borne in mind that a lethal dose is about 10 times higher than normal but this threshold is considerably reduced in case of simultaneous intake of other substances with effects similar to barbiturates, such as alcohol, benzodiazepines, heroin, opiates and tranquilizers.

Even abrupt cessation of taking barbiturates can lead to serious side effects and the onset of withdrawal symptoms with symptoms such as:

  • heavy sweating
  • tremors
  • state of anxiety
  • nausea or vomiting
  • high blood pressure (hypertension)
  • rapid heartbeat (tachycardia)
  • nightmares
  • convulsions
  • delusions

The most severe form of barbiturate withdrawal seizures is a psychotic and psychomotor state comparable to "alcohol withdrawal, known as"delirium tremens'.

After discontinuing the use of barbiturates, the body may need time to adapt to the suspension which, if taken in high doses or for a long period of time, could be up to 15 days. During this period it is advisable to remain under medical supervision and consult him if unwanted or serious episodes occur. In addition, vital functions such as heart rate, blood pressure and body temperature should be checked daily.

Contraindications

The use of barbiturates is contraindicated in the presence of one or more conditions that may increase the risk of serious adverse reactions, such as:

  • overt allergy to the product
  • liver failure
  • kidney failure
  • severe respiratory failure
  • porphyrias (rare metabolic diseases)
  • pregnancy
  • feeding time
  • intake of alcohol, benzodiazepines, heroin, opiates and tranquilizers

Interactions with other medicines

Barbiturates can interact with other drugs when taken at the same time, altering the body's response to one or more drugs.

Barbiturates add their effects to alcohol but also to other central nervous system depressant drugs, such as:

  • antihistamines o medicines for hay fever, other allergies or colds
  • sedatives, tranquilizers or medicines to induce sleep
  • pain relieving or narcotic medications
  • antiepileptic drugs
  • muscle relaxants
  • anesthetics

Barbiturates stimulate liver enzymes, molecules that cause the breakdown of many drugs.Therefore, if taken together with barbiturates there may be a decrease in the efficacy of medicines such as anticoagulants, beta-blockers, HIV drugs, cortisones, antidepressants, antiepileptics, antibiotics, antipsychotics, immunosuppressants, digitalis glycosides, antiarrhythmics, B vitamins, antiemetics , antifungals, opioids, antiasthmatics. Furthermore, taking barbiturates can reduce the efficacy of contraceptive drugs such as estrogen and progestogen.

In turn, some drugs can affect the action of barbiturates. For example, amphetamines and some antiepileptics can inhibit the metabolism of some barbiturates, such as phenobarbital, increasing their toxicity.

Bibliography

Skibiski J, Abdijadid S. Barbiturates. StatPearls [Internet]. 2021; Feb 09

Italian Medicines Agency (AIFA). Medicines database

In-depth link

Mayo Clinic. Barbiturate (Oral Route, Parenteral Route, Rectal Route) (English)

MedlinePlus. Barbiturate intoxication and overdose (English)

Editor'S Choice 2022

Race

Race

The differences in the color of the skin, eyes and hair, which are the first things that the human eye notices and uses to categorize individuals, are of little importance if we look at the DNA that is truly responsible for how human beings are made

Amoebiasis

Amoebiasis

Amoebiasis is an infectious disease caused by the protozoan Entamoeba histolytica which normally lives in the intestinal canal (lumen); Sometimes, this parasite begins to multiply causing an intestinal infection and, within 2-4 weeks, symptoms