Benzodiazepine is a drug that acts in the CNS and has an anxiolytic and sedative effect.
Effect
Stimulating and inhibiting nerve fibres and nerve cells coexist in the CNS. The associated messenger substances (transmitters) also have an excitatory or inhibitory effect. The main transmitter of the inhibiting nerve fibres is GABA (gamma-aminobutyric acid).
This substance binds to specific sites (GABA receptors) of a nerve cell and thus inhibits its activity. The GABA receptors in turn have a binding site for benzodiazepines. When a benzodiazepine binds to a GABA receptor, the GABA receptor is more strongly activated, thus increasing the inhibitory effect of GABA. Inhibitory fibres have calming and anxiety-relieving effects in the human body, so a benzodiazepine is able to enhance these effects. Benzodiazepines are therefore also known as GABA receptor agonists (enhancers).
Active ingredients
Within the group of benzodiazepines there are a large number of individual active substances which have different effects and thus have many different areas of use. Benzodiazepines act either as sedatives (tranquillisers, sedatives), anxiolytics, hypnotics (sleep inducers) or antispasmodics (antiepileptics). Tranquilizers are for example bentazepam or lopralozam.
Anti-anxiety drugs include etizolam or clotiazepam. Nitrazepam and temazepam are used as sleep-inducing drugs. Clonazolam and clonazepam are anticonvulsants.
Some of the benzodiazepines do not have only one effect, they do several things at once. Diazepam, probably the best-known benzodiazepine, has an anxiety-relieving and sedative effect as well as an antispasmodic effect. The various active substances differ greatly in their respective half-lives, i.e. the time after which only half of the amount of the drug originally administered remains in the body. They therefore all have different lengths of action, and the effect can vary greatly.
Fields of application
Benzodiazepines are widely used in almost all areas, but especially in anaesthesia to induce anaesthesia. The sedative and anxiolytic effects of this class of drugs are used to induce anaesthesia. The anxiolytic component of benzodiazepines also plays an important role in psychotherapy in the treatment of anxiety and restlessness.
Epileptic seizures can be broken down or prevented thanks to the anticonvulsant effect. Benzodiazepines also serve a useful purpose as a means of falling asleep or sleeping through the night. In muscle spasms they relax the muscles.
Dosage forms
Benzodiazepines are available only on prescription. They are most commonly supplied in tablet form. As tablets, they are used mainly as sedatives or to help people fall asleep. The benzodiazepines are administered intravenously through an intravenous cannula or by injection in hospital, in preparation for surgery or in emergency medicine, for example in the event of an epileptic seizure.
Risks
Risks of benzodiazepine use include side effects such as fatigue, listlessness, headaches, muscle weakness and drowsiness. There is a reduction in responsiveness and cognitive ability, and driving a vehicle or operating machinery is not recommended when taking benzodiazepines. In addition, long-term benzodiazepine use is risky because of the risk of developing tolerance.
Tolerance often leads to dependence. Although benzodiazepines are not as addictive as, for example, barbiturates, long-term use should be carefully considered and discussed with the doctor. Addiction leads to withdrawal symptoms such as headaches, tremors, restlessness and nervousness.
Finally, if the withdrawal symptoms are very strong, cramps may also occur. Intoxication with benzodiazepines results from either accidental or deliberate misuse of the drug. Accidental misuse, either too much at once or in combination with alcohol, greatly increases the effects of benzodiazepines.
Intentional misuse for suicidal purposes also occurs, although benzodiazepines are not suitable for suicide because they do not have an inhibitory effect on the respiratory centre. Symptoms of benzodiazepine poisoning include loss of consciousness, nausea and vomiting. In later stages of poisoning patients become completely unconscious, have no protective reflexes and do not respond to pain stimuli.
Therapeutic measures are primarily aimed at securing the patient’s airways. Since all protective reflexes fail, the affected person is no longer able to cough, for example. Any vomit is simply swallowed, gets into the lungs and there is a risk of pneumonia.
In the clinic, the airways are secured by means of a tube (tube) which is pushed into the windpipe. As a first aid measure, a stable lateral position is recommended to secure breathing. The airways are kept open, vomit and secretion can run out of the sideways directed mouth.
In the clinic further measures follow, such as a gastric lavage or the use of water-draining drugs (diuretics). Another way to treat poisoning with benzodiazepines is to administer an antidote. Flumazenil is one such antidote.
It is a so-called benzodiazepine antagonist (attenuator), which means that the substance blocks the binding sites for benzodiazepines at the GABA receptor. Benzodiazepines are then no longer able to act. Flumazenil is broken down very quickly by the body.
In cases of poisoning with high doses of benzodiazepine, the antidote must be administered frequently to achieve success. Flumazenil is not indicated in patients dependent on benzodiazepines. If the benzodiazepines stop working as abruptly as flumazenil does, withdrawal symptoms are severe. The use of flumazenil as a benzodiazepine antagonist should therefore be used with caution and should not be undertaken until it is clear whether the patient has been taking benzodiazepines for a long period of time.
