sedative-hypnotic drug
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What is a sedative-hypnotic drug?
Sedative-hypnotic drugs are chemical substances that reduce tension and anxiety and induce calm (sedative effect) or induce sleep (hypnotic effect). Most have a calming effect at low doses and induce sleep at higher doses, generally by depressing the central nervous system.
Examples of sedative-hypnotics include barbiturates, benzodiazepines, and nonbenzodiazepine drugs like zolpidem. While barbiturates were once common sleeping pills, benzodiazepines are now more frequently prescribed due to their reduced risk of tolerance, addiction, and central nervous system depression.
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What are sedative-hypnotic drugs used for?
Sedative-hypnotic drugs reduce tension and anxiety, induce calm (sedative effect), or induce sleep (hypnotic effect). They generally depress the central nervous system and selectively achieve their effects without affecting mood or reducing sensitivity to pain.
These drugs are often prescribed as sleeping aids, sedatives, energizers, mood elevators, stimulants, and tranquilizers. They can relieve anxiety and help patients cope with environmental or personal factors that trigger symptoms. Examples include barbiturates like phenobarbital, benzodiazepines like diazepam (Valium), and nonbenzodiazepines like zolpidem (Ambien).
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How do sedative-hypnotic drugs affect the body and mind?
Sedative-hypnotic drugs reduce tension and anxiety and induce calm or sleep by depressing the central nervous system. These drugs can cause central-nervous-system depression, loss of consciousness, and death.
At low doses, they relieve tension and anxiety without drowsiness, acting on brain centers involved in behavioral control, leading to increased talkativeness and social interaction. Higher doses induce sleep but don't affect pain perception.
Common side effects range from nervousness and nausea to confusion and euphoria. Long-term use can lead to tolerance, habituation, psychological dependence, and, in higher doses, physical dependence, with severe withdrawal symptoms.
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What are some common examples of sedative-hypnotic drugs?
Sedative-hypnotic drugs reduce tension, anxiety, and induce calm or sleep by depressing the central nervous system.
Examples include:
* Barbiturates Phenobarbital, secobarbital, and pentobarbital, used as sedatives and hypnotics, have been replaced by benzodiazepines due to risks of tolerance, addiction, and central nervous system depression.
* Benzodiazepines Drugs like diazepam (Valium), chlordiazepoxide (Librium), and alprazolam (Xanax) relieve anxiety but can cause dependency with long-term use.
* Zolpidem A nonbenzodiazepine drug used to treat insomnia, decreasing neuron excitability. Trade names include Ambien, Edluar, Intermezzo, and Zolpimist.
* Chloral hydrate A derivative of ethyl alcohol, was introduced in 1869 as a synthetic sedative-hypnotic.5 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are possible risks or side effects of using sedative-hypnotic drugs?
Sedative-hypnotic drugs, such as zolpidem and benzodiazepines, can cause side effects, including daytime sleepiness, confusion, and reduced alertness. More severe side effects can include hallucinations, amnesia, and, in rare instances, complex sleep behaviors like sleepwalking or sleep driving.
These drugs can lead to tolerance, where the user needs larger doses to achieve the desired effect, and long-term use can result in drug dependence and withdrawal symptoms like anxiety and restlessness. Because of the risk of dependence, these medications should be taken at the lowest possible dose for a short period of time.
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Why should sedative-hypnotic drugs only be used under a doctor’s supervision?
Sedative-hypnotic drugs, which include barbiturates, benzodiazepines, and zolpidem, should only be used under a doctor’s supervision because they can cause central nervous system depression, and combining them with other substances, like alcohol and opioids, heightens the risk of adverse events, such as hallucinations, respiratory depression, and even death.
These drugs can also lead to tolerance and addiction, requiring higher doses to achieve the same effect and causing withdrawal symptoms like anxiety and restlessness upon cessation. Long-term use can result in dependency, making it difficult to stop, and abrupt cessation may lead to serious withdrawal symptoms. Additionally, some drugs may induce complex sleep behaviors, where individuals engage in activities without being fully awake.
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sedative-hypnotic drug, chemical substance used to reduce tension and anxiety and induce calm (sedative effect) or to induce sleep (hypnotic effect). Most such drugs exert a quieting or calming effect at low doses and a sleep-inducing effect in larger doses. Sedative-hypnotic drugs tend to depress the central nervous system. Since these actions can be obtained with other drugs, such as opiates, the distinctive characteristic of sedative-hypnotics is their selective ability to achieve their effects without affecting mood or reducing sensitivity to pain.
For centuries alcohol and opium were the only drugs available that had sedative-hypnotic effects. The first substance introduced specifically as a sedative and as a hypnotic was a liquid solution of bromide salts, which came into use in the 1800s. Chloral hydrate, a derivative of ethyl alcohol, was introduced in 1869 as a synthetic sedative-hypnotic; it was used notoriously as “knock-out” drops. Paraldehyde was introduced into clinical medicine in the 1880s and was followed by the synthesis of barbital in 1903. Phenobarbital became available in 1912 and was followed, during the next 20 years, by a long series of other barbiturates. In the mid-20th century new types of sedative-hypnotic drugs were synthesized, chief among them the benzodiazepines (the so-called minor tranquilizers).
Barbiturates were extensively used as “sleeping pills” throughout the first half of the 20th century. They also were used to reduce voluntary inhibition during psychiatric examinations (for which they have sometimes been dubbed “truth serums”). Among the most commonly prescribed kinds were phenobarbital, secobarbital (marketed under Seconal and other trade names), amobarbital (Amytal), and pentobarbital (Nembutal). When taken in high-enough doses, these drugs are capable of producing a deep unconsciousness that makes them useful as general anesthetics. In still higher doses, however, they depress the central nervous and respiratory systems to the point of coma, respiratory failure, and death. Additionally, the prolonged use of barbiturates for relief of insomnia leads to tolerance, in which the user requires amounts of the drug much in excess of the initial therapeutic dose, and to addiction, in which denial of the drug precipitates withdrawal, as indicated by such symptoms as restlessness, anxiety, weakness, insomnia, nausea, and convulsions. Analysis of electroencephalographic (EEG) patterns during barbiturate-induced sleep has further revealed that the use of some of these drugs produces sleep disruption.
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The use of barbiturates declined after the development in the 1950s of the benzodiazepines. The latter are more effective in relieving anxiety than in inducing sleep, but they are superior to barbiturates because of the reduced dangers they present of tolerance and addiction and because they are much less likely to injuriously depress the central nervous system when used at high doses. They also require a much smaller dosage than barbiturates to achieve their effects. The benzodiazepines include chlordiazepoxide (Librium), diazepam (Valium), alprazolam (Xanax), oxazepam (Serax), and triazolam (Halcion). They are, however, intended only for short- or medium-term use, since the body does develop a tolerance to them and withdrawal symptoms (anxiety, restlessness, and so on) develop even in those who have used the drugs for only four to six weeks. The benzodiazepines are thought to accomplish their effect within the brain by facilitating the action of the neurotransmitter gamma-aminobutyric acid, which is known to inhibit anxiety.
Antipsychotic drugs (major tranquilizers), tricyclic antidepressants, and antihistamines can also induce drowsiness, though this is not their primary function. Most over-the-counter sleeping aids use antihistamines as their active ingredient.
Alcoholic beverages in particular are only of modest benefit in inducing sleep. On frequent exposure to alcohol, the nervous system adapts to the drug, and this results in early-morning awakening.