Difference between revisions of "Barbiturates"

Latest revision as of 05:59, April 2, 2019

Barbiturates are drugs that depress the central nervous system and are often called sleeping pills.[1]

Pharmacology

Barbiturates increase the flow of chloride ions across the neuronal membrane causing hyperpolarization (a more negative resting membrane potential). This occurs by binding the ionotropic receptor for the endogenous neurotransmitter known as gamma-amino-butyric-acid or GABA (Principally the GABAa isoform of the receptor). The increased chloride ion flow reduces the chance that an excitatory action potential will be generated. This is the way in which barbiturates act as depressants of the central nervous system and are effective sedatives, anxiolytics, and anticonvulsants.

Trivia

The barbiturate called sodium pentothal is known as truth serum. In heavy doses, it is used for lethal injections. [2]

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-'''Barbiturates''' are drugs that depress the central nervous system and are often called ''sleeping pills''. The first barbiturates were made in the 1840s by the [[Bayer]] laboratories in [[Germany]]. In 1913, the first barbiturate (''barbitol'') was used in medical practices. In 1922, a common barbiturate, ''Phenobarbital'', was introduced.
+'''Barbiturates''' are drugs that depress the central nervous system and are often called ''sleeping pills''.[http://faculty.washington.edu/chudler/barb.html]
-There are many different types of barbiturates. The names of some common ones (and brand names) include Pentobarbital (Nembutal), Secobarbital (Seconal), Amobarbital (Amytal) and Phenobarbital (Luminal); slang names for these barbiturates include yellow jackets, reds, blues, Amy's, and rainbows.
+==Pharmacology==
+Barbiturates increase the flow of chloride ions across the neuronal membrane causing hyperpolarization (a more negative resting membrane potential). This occurs by binding the [[ionotropic receptor]] for the endogenous neurotransmitter known as gamma-amino-butyric-acid or ''[[GABA]]'' (Principally the GABAa isoform of the receptor). The increased chloride ion flow reduces the chance that an excitatory action potential will be generated. This is the way in which barbiturates act as depressants of the central nervous system and are effective sedatives, anxiolytics, and anticonvulsants.
-Barbiturates have been used extensively in the past as [[sedative]]s. A new group of drugs called "benzodiazepines" has replaced many of the barbiturates. However, barbiturates are still used to treat some types of [[epilepsy]].
-==Effects==
-Barbiturates have several effects on behavior depending on the dose:
-Low dosage: reduced [[anxiety]]; reduced [[respiration]], reduced [[blood pressure]], reduced [[heart rate]] and reduced rapid eye movement ([[REM]]) sleep.
-High dosage: increased/stimulated behavior (effects may be caused by depression of inhibitory brain circuits)
-Barbiturates can lead to excessive sedation and cause anesthesia, [[coma]] and even [[death]]. Barbiturate overdoses may occur because the effective dose of the drug is not too far away from the lethal dose.
-A major problem with barbiturates is that they may lead to [[tolerance]] and [[dependence]]. Tolerance occurs when a greater and greater and greater amount of the drug is required to get the desired effect. For example, if barbiturates are used to help a person [[sleep]], over time and after much usage, a greater dose of the drug will be needed to get the person to sleep. Dependence occurs when a person feels like he or she must use the drug and [[withdrawal]] symptoms occur when the person stops using the drug.
-Withdrawal symptoms that occur when people try to "kick the habit" of using barbiturates include:
-* [[anxiety]]
-* [[insomnia]]
-* [[seizure]]s
-* [[hissy fit]]s
-* [[nausea]], [[stomach]] problems
-* [[hallucination]]s
-==Barbiturates and the [[Brain]]==
-Barbiturates dissolve easily in [[fat]]. Therefore, barbiturates have ready access to the brain because your brain is made of fat. Also, because barbiturates dissolve into body fat, they can accumulate and re-enter the [[blood]] stream later. Different barbiturates clear out of the blood stream at different rates.
-Although the exact mechanisms by which barbiturates affect the brain are not understood, it is thought that these drugs bind to [[sodium]] channels on neurons and prevent the flow of sodium ions. Because sodium ions cannot flow across the neuronal membrane, action potentials cannot be produced.
-Barbiturates may also increase the flow of chloride ions across the neuronal membrane. This may occur through binding to the receptor for the neurotransmitter called ''BAGA''. The increased chlorine ion flow reduces the chance that an action potential will be generated.
 ==Trivia==
-* The barbiturate called [[sodium pentothal]] is known as ''truth serum.''
+* The barbiturate called [[sodium pentothal]] is known as ''truth serum.'' In heavy doses, it is used for lethal injections. [https://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2006/09/30/BAGK7LFNST1.DTL]
-[[category:drugs]]
+[[Category:Drugs]]