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Cards In This Set
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Name the major classes of sedative hypnotics
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1. Benzodiazepines (major class)
2. Barbiturates (eg phenobarbitol). ultra short, short, or long acting 3. Newer hypnotics - zolpidem, eszopiclone, zaleplon 4. Carbamates- meprobamate 5. alcohols - EtOH, chloral hydrate 6. Atypicals- buspirone (selective anxiolytic) and ramelteon (selective sleep) |
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Name some long-acting benzodiazepines
Name some other benzodiazepines |
Diazepam, chlordiazepoxide, chlorazepate
alprazolam, clonazepam, flurazepam, lorazepam, oxazepam, triazolam |
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Name some barbiturates
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Phenobarbital, pentobarbital,amobarbital, secobarbital, thiopental.
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Which sedative hypnotic is commonly used to induce anesthesia?
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Thiopental
Very high lipid solubility, enters CNS quickly. Then actions are terminated by redistribution to other tissues. |
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Order the five shortest acting sedative hypnotics
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Zaleplon
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How are benzodiazepines metabolized?
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Most are converted to active metabolites by the liver. may build up. Lorazepam and oxazepam undergo hepatic conjugation but are not converted to active metabolites.
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Which sedative hypnotic does not have to be metabolized by the liver prior to secretion?
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Only phenobarbital is excreted partly unchanged in the urine.
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Name 4 long-acting (>30hrs) sedative hypnotics
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Chlordiazepoxide, chlorazepate, diazepam, phenobarbitol
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How is chloral hydrate metabolized?
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By liver to trichloroethanol, an active metabolite.
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How do benzodiazepines work?
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Bind BZ R, located in thalamus, limbic structures, and cortex. Part of GABA A receptor-chloride channel. binds between a1 and y2 subunit, also binds isoforms with a2, a3, or a5.
Leads to increased frequency of GABAA chloride channel opening |
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What can reverse CNS effects of benzodiazepines?
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Flumazenil
Will also reverse effects of newer hypnotics (zolpidem, eszopiclone, and zaleplon) but NOT barbiturates! |
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What effect do some B-carbolines have?
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Bind to BZ R's with high affinity, can cause anxiogenic and convulsant effects. classified as inverse agonists.
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How do the barbiturates work?
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Depress neurons in the midbrain reticular formation, prolonging GABA/glycine effects. Also bind to GABAA R but at different site than benzodiazepines (NOT antag. by flumazenil!).
Increase duration of chloride channel opening. May also block glutamate (excitatory), and at high conc., Na channels. |
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How do the newer hypnotics (zolpidem, zaleplon, eszopiclone) work?
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Also interact with BZ Receptors, but only those with a1 subunits. Called BZ1 or omega1. Antagonize with flumazenil!
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Describe the dose-dependent effects of sedative-hypnotics
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Sedation/anxiolysis -> hypnosis (sleep) -> anesthesia -> medullary depression -> coma.
Note that barbiturates are easier to OD on than benzodiazepines or newer hypnotics (eg zolpidem). |
