There is a group of drugs, which all have similar sedating qualities, known as downers. The word downer is an umbrella term which includes benzodiazapines, barbiturates, and alcohol. Downers are also occasionally referred to as tranquilizers, hypnotic sedatives, or depressants. Because of the widespread social use of alcohol, it is often considered its own class of drug.
The common denominator for downers is their effect on the neurotransmitter gamma-aminobutyric acid, or GABA. GABA is responsible for calming the central nervous system, slowing heart rate, breathing, and inducing sleep. Effectively, it works to counter the effects of the neurotransmitter norepinephrine, and the two work together to maintain correct heart rate, and alertness. Too much norepinephrine may lead to numerous anxiety disorders and might be responsible for ‘panic attacks’, and so downers are often prescribed to treat these conditions.
Narcotics and opiate based pain killers are occasionally lumped together with downers. While opiates do create a sedating effect on the body, they do not directly effect the neurotransmitter GABA and are therefore a different class of drugs.
The most usually prescribed downers today are the benzodiazapines, sometimes called benzos. The more well-known benzodiazapines include diazepam (Valium), chlordiazepoxide (Librium), alprazolam (Xanax), lorazepam (Ativan), and clonazepam (Klonopin). These drugs are most commonly prescribed for anxiety disorders, but also find uses in preventing seizures, and as muscle relaxants.
Barbiturates were popularly used medically before the discovery of benzodiazapines in the 1950s. Barbiturates are chemicals derived from the chemical barbituric acid. The most common barbiturates include phenobarbital, pentobarbital, secobarbital, butalbital, butabarbital and sodium thiopental. Barbiturates are notably more toxic than benzodiazapines, and have quite a lower therapeutic index. A therapeutic index is the range between the minimally effective therapeutic dose and the lethal dose of the substance. A narrow index means that a lethal dose of the drug is not much more than the recommended dosage, and the drug is therefore risky. For these reasons, benzodiazapines have largely replaced barbiturates for use as medications. Barbiturates are still found in several pain medications, and find use as general anesthetics.
Downers each have a high potential for abuse, and are extremely addictive chemicals. As a class of drugs that includes alcohol, they are by far the most widely abused drugs on the planet. Even without alcohol, they rank amongst the most abused and addictive prescription drugs. Because of their high therapeutic index and low toxicity, benzodiazapines are especially easy to develop a physical dependence on. All downers, including alcohol, have very serious withdrawal symptoms, and should not be discontinued from everyday use without consulting a physician or medical professional before doing so.