Thursday, September 17, 2015

33. Sedatives

Barbituric acid

Barbiturates are drugs that act as central nervous system depressants, and by virtue of this they produce a wide spectrum of effects, from mild sedation to anesthesia. Some are also used as anticonvulsants. Barbiturates are derivatives of barbituric acid.
Like a bug.

https://en.wikipedia.org/wiki/Barbiturates

Barbiturates are drugs that act as central nervous system depressants, and can therefore produce a wide spectrum of effects, from mild sedation to total anesthesia. They are also effective as anxiolytics, hypnotics, and anticonvulsants. Barbiturates also have analgesic effects; however, these effects are somewhat weak, preventing barbiturates from being used in surgery in the absence of other analgesics (opioids or volatile anesthetics such as halothane). They have addiction potential, both physical and psychological. Barbiturates have now largely been replaced by benzodiazepines in routine medical practice – for example, in the treatment of anxiety and insomnia – mainly because benzodiazepines are significantly less dangerous in overdose as there is no specific antidote for barbiturate overdose. However, barbiturates are still used in general anesthesia, for epilepsy, for the treatment of acute migraines and cluster headaches (in the compound drugs Fioricet and Fiorinal) (under stringent protocols with mandatory physician monitoring for addiction and abuse), and (where legal) assisted suicide and euthanasia.[1] Barbiturates are derivatives of barbituric acid.[2]


Barbiturate sind Derivate der Barbitursäure, allerdings keine Salze oder Ester, wie der Name suggeriert. Die meist aliphatischen Substituenten sind gewöhnlich am Kohlenstoff-Atom Nummer 5 der Barbitursäure zu finden.
Barbitursäure wurde erstmals 1864 von Adolf von Baeyer hergestellt.[1] Barbitursäurederivate waren für viele Jahrzehnte die Schlafmittel schlechthin. Das erste Barbiturat mit schlafanstoßender Wirkung (Barbital) wurde 1903 von Emil Fischer synthetisiert.[2] Seit 1992 sind sie in Deutschland und der Schweiz als solche nicht mehr zugelassen und unterliegen in Deutschland – bis auf einige Ausnahmen – der Betäubungsmittel-Verschreibungsverordnung (BtMVV).
Das Barbitursäurederivat Thiopental kann zur intravenösen Einleitung und Aufrechterhaltung einer Narkose verwendet werden, Barbital (Handelsname Veronal) als Puffer (Veronal-Acetat-Puffer) in der Biochemie.

Les barbituriques appartiennent à une famille médicamenteuse agissant comme dépresseurs du système nerveux central, et dont le spectre d'activité s'étend de l'effet sédatif à l'anesthésie. Certains sont aussi utilisés pour leurs vertus anti-convulsivantes. Tous sont dérivés de l'acide barbiturique et de ses homologues (acide thiobarbiturique, acide iminobarbiturique)1. Ils sont de nos jours beaucoup moins prescrits en raison de leurs effets indésirables, du risque d'abus, et de l'arrivée sur le marché de molécules aux effets similaires mais sans les effets délétères des barbituriques.

Los barbitúricos son una familia de fármacos derivados del ácido barbitúrico que actúan como sedantes del sistema nervioso central y producen un amplio esquema de efectos, desde sedación suave hasta anestesia total.
También son efectivos como ansiolíticos, como hipnóticos y como anticonvulsivos. Los barbitúricos también tienen efectos analgésicos, sin embargo, estos efectos son algo débiles, impidiendo que los barbitúricos sean utilizados en cirugía en ausencia de otros analgésicos.
Tienen un alto potencial de adicción, tanto física como psicológica. Los barbitúricos han sido reemplazados por las benzodiacepinas en la práctica médica de rutina, por ejemplo, en el tratamiento de la ansiedad y el insomnio, principalmente porque las benzodiacepinas son mucho menos peligrosas en sobredosis. Sin embargo, todavía se utilizan barbitúricos en la anestesia general, para la epilepsia y el suicidio asistido.
En forma endovenosa el pentotal ha sido el más utilizado para la inducción de la anestesia aunque en los últimos años está siendo desplazado por un anestésico intravenoso no barbitúrico, el propofol, de vida media más corta. También son utilizados como anticonvulsivantes (fenobarbital, por ejemplo).
 Ambien

Ambien or Zolpidem is a prescription medication used for the short-term treatment of insomnia, as well as some brain disorders.


Zolpidem (brand names Ambien, Ambien CR, Intermezzo, Stilnox, Stilnoct, Sublinox, Hypnogen, Lunata, Zonadin, Sanval, Zolsana and Zolfresh) is a prescription medication used for the treatment of insomnia and some brain disorders.[2] It is a short-acting nonbenzodiazepine hypnotic of the imidazopyridine class[3] that potentiates GABA, an inhibitory neurotransmitter, by binding to GABAA receptors at the same location as benzodiazepines.[4] It works quickly, usually within 15 minutes, and has a short half-life of two to three hours.
Zolpidem has not adequately demonstrated effectiveness in maintaining sleep, unless delivered in a controlled-release (CR) form. However, it is effective in initiating sleep.[5] Its hypnotic effects are similar to those of the benzodiazepine class of drugs, but it is molecularly distinct from the classical benzodiazepine molecule and is classified as an imidazopyridine. Flumazenil, a benzodiazepine receptor antagonist, which is used for benzodiazepine overdose, can also reverse zolpidem's sedative/hypnotic and memory-impairing effects.[6][7]
Zolpidem has slight muscle relaxant and anticonvulsant properties, but has not been approved for use in muscle relaxation or seizure prevention. This is because the dosage of drug needed to cause muscle relaxation is 10 times the sedating dose, and the dosage needed for preventing seizures is 20 times the sedating dose;[8] high dosages are more likely to cause unpleasant side effects such as hallucinations and amnesia. Contrary to early studies, more recent research has indicated that zolpidem is in fact a potent anticonvulsant.[9] The anticonvulsant effects are not realized until the normal dosage range has been surpassed (meaning sedation would still be a major side effect) but the threshold for this effect is now believed to be considerably lower than original estimates.
The United States patent for zolpidem was held by the French pharmaceutical corporation Sanofi-Aventis.[10] On April 23, 2007, the U.S. Food and Drug Administration (FDA) approved 13 generic versions of zolpidem tartrate.[11] Zolpidem is available from several generic manufacturers in the UK, as a generic from Sandoz in South Africa and TEVA in Israel, as well as from other manufacturers such as Ratiopharm and Takeda GmbH (both Germany).
On January 10, 2013, the Food and Drug Administration announced it is requiring the manufacturer of Ambien and Zolpimist to cut the recommended dosage for women in half, after laboratory studies showed that the medicines can leave patients drowsy in the morning and at risk for motor vehicle collisions. The FDA recommended that manufacturers extend the new dosage cuts to men as well, who process the drug at a faster rate; however, the reasons men and women metabolize the drugs at different rates are still unknown.[12] In May 2013, the FDA approved label changes specifying new dosage recommendations for zolpidem products because of concerns regarding next-morning impairment.[13]

Zolpidem ist ein Arzneistoff, der in modernen Schlafmitteln bzw. Einschlafmitteln eingesetzt wird. Der Stoff ist strukturell ein Imidazopyridin-Abkömmling mit einem den Benzodiazepinen ähnlichem Wirkspektrum und zählt neben Zopiclon und Zaleplon zu den Z-Drugs. Zolpidem hat üblicherweise eine sehr kurze Halbwertszeit (2–3 Stunden) und bildet keine pharmakologisch wirksamen Metaboliten. In vereinzelten Fällen werden jedoch auch bei weitem höhere Halbwertszeiten beobachtet (bis 9.9 Stunden). Es ist momentan das in den USA und in Europa meistverordnete Schlafmittel. Zolpidem wird vom Körper schnell und leicht aufgenommen, der maximale Plasmaspiegel wird nach etwa zwei Stunden erreicht.

Le zolpidem est un sédatif-hypnotique de la classe des imidazopyridines. C'est un somnifère très puissant. Il est classé parmi les psychotropes à risque d'abus2 et les drogues entraînant une toxicomanie3. En France, le Stilnox et ses génériques font l'objet d'un suivi renforcé4 par l'ANSM en raison de leurs utilisations détournées. Il ressemble beaucoup à l'alpidem, un médicament appartenant à la même classe mais retiré du marché du fait d'effets secondaires très grave pour le corps en général et le foie en particulier.

El zolpidem es un análogo de benzodiazepinas pero no una benzodiazepina en sí, sino un fármaco hipnótico, con una estructura imidazopiridínica que lo hace parecido a la de aquellas. Actúa sobre el mismo receptor de las benzodiazepinas y sobre el mismo centro activo del canal de cloro. A diferencia de estas, el zolpidem no tiene efectos a nivel medular, ya que no se une a los receptores allí ubicados.
 


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