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Sedatives

This group of substances includes two families of drugs, benzodiazepines and barbiturates. These medications were developed for relieving tension and anxiety and inducing sleep. Benzodiazepines are still extensively used for these purposes in medical settings, while barbiturate prescriptions have declined significantly because they can be fatal in overdose.

How Sedatives Work

Benzodiazepines and barbiturates most commonly come in pill form, though intravenous preparations also exist. When ingested, these medications usually give an effect within 30 minutes, and the effects can continue for a couple of hours and up to 20 hours depending on whether it a short-acting or long-acting kind. Benzodiazepines and barbiturates can be detected in urine up to a week after use.

Sedatives work by stimulating GABA receptors in the brain. GABA is the main inhibitory neurotransmitter in the brain, which means that its actions serve to reduce the activity of other brain systems. Stimulating GABA thus causes a reduction in overall brain activity, and this is how these drugs lower anxiety and induce sleep.

When benzodiazepines bind to GABA receptors they make these receptors more responsive to the actions of GABA. Barbiturates, on the other hand, can stimulate GABA receptors directly, meaning that they can mimic the actions of GABA.

Regular Sedative Use

Benzodiazepines are commonly prescribed for various medical uses. They can serve as anticonvulsants to control and prevent seizures, they are used as muscle relaxants, they help to control anxiety, and they can induce sleep in people with insomnia.

Barbiturates have similar medical indications but they have been largely replaced by the benzodiazepines, which do not have the same risk of fatality in overdose.

Sedative Intoxication

Although sedatives generally induce states of calmness, they also reduce people's inhibitions, and in some cases this can lead to an unleashing of impulsive and potentially inappropriate or aggressive behavior.

Sedatives reduce people's mental alertness and coordination and it is thus dangerous to be driving or operating heavy machinery while under the influence of these drugs.

High doses can cause states of confusion, slurred speech, unsteadiness and incoordination. Overdoses can lead to unconsciousness. Overdoses of barbiturates can be fatal by causing respiratory depression. Although benzodiazepine overdoses are usually not fatal, they can be if combined with alcohol, or if they occur in individuals with preexisting respiratory problems.

Effects of Long-Term Regular Sedative Use

When used on a daily basis for periods of a few weeks or more, sedatives can lead to tolerance, where increasingly large doses are required in order to produce similar effects. Abruptly discontinuing sedatives after long-term use can lead to a potentially life-threatening withdrawal syndrome (see below). Sedatives can also contribute to reduced mental alertness, concentration and memory difficulties, and depressive symptoms.

Sedative Withdrawal

With long-term regular use of sedatives, GABA receptors in the brain will be reduced, which is the brain's way of compensating for the constant input of the sedatives that are over-stimulating the GABA system. If the sedatives are then suddenly stopped, the brain will be in a state of GABA shortage, and brain functions will then be pushed into hyperactivity.

The severity of the withdrawal symptoms will be proportional to the size of the sedative dose that was being used on a regular basis. With heavy sedative use, the syndrome will be the same as Delirium Tremens seen in alcohol withdrawal. More moderate doses will produce some of these symptoms.

In the first stages of this syndrome, the individual will experience tremors, autonomic hyperactivity (sweating, fever, elevated blood pressure, rapid heart rate), anxiety, agitation, nausea, vomiting, and insomnia.

If left untreated, the next symptoms to appear are confusion and disorientation, hallucinations (mainly visual ones, but also auditory, tactile and olfactory) and delusions.

Seizures and cardiovascular collapse can then ensue, and are the most concerning symptoms.

If untreated, Delirium Tremens can result in death and is thus considered a medical emergency. The main treatment is to restart the sedatives, which will resolve all of the withdrawal symptoms quickly.

Treating Sedative Abuse and Dependence

Treating sedative use disorders follows the general treatment principles as outlined here. Long-acting benzodiazepines can be prescribed in a controlled and regulated fashion, and tapered very gradually over several weeks or months, as a way to lead into abstinence.

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