Part II: Anxiety and Sleep Flashcards
Barbiturates prolong the inhibitory effects of GABA and glycine thus depressing neuronal activity in the
midbrain reticular formation
How do barbiturates affect GABA-mediated chloride ion channel opening?
Increases the duration of GABA-mediated Cl-channel opening
They may also block Glutamic acid (excitatory) and Na-channels at high concentrations
Are Barbiturates antagonized by flumazenil (a BZ receptor antagonist)?
No. Unlike Benzodiazepines which are antagonized by Flumazenil, Barbiturates do not have antagonists
CNS drugs are able to reach the CNS based on characteristics including Lipophilicity. The lipophilic nature of drugs allowing them to enter the CNS means that they can also cross the
Placenta
Benzodiazepines is an allosteric modulator of the GABAa receptor different from the Barbiturate receptor. How do the diazepines alter GABA’s ability to affect the GABA channel?
When benzos bind, takes less GABA to open the channel
Short acting benzos (2-4hours)
Midazolam (IV, anesthesia/pre-anethesia)
Triazolam (hypnotic)
Moderate Acting benzos (10-14)
Alprazolam
Chlordiazepoxide
Lorazepam
Long acting benzo used for anti-convulsant (24 hour half life)
Clonazepam
Very long acting benzos because they have active metabolites
Diazepam (43 hours, can be IV used for status epilepticus, also rectal)
Flurazepam (74 hour half life)
Date rape drug that is very fast acting
Flunitrazepam
Benzodiazepam antagonist
Flumazinil. Used to reverse overdose of benzodiazepine
Benzodiazepines are highly protein bound but counterintuitively have
few drug interactions
Benzodiazepine receptor agonists are different than the benzodiazepines because they bind to the receptor but have
non-benzo structure
BZ1 selective Agonists:
Zolpidem
Zaleplon
Non-selective Non-benzo BZ receptor agonist
Eszopiclone
Non-depressant anxiolytic that doesn’t have much abuse liability but people like taking it with benzos and acts on 5-HT1A as a partial agonist but generally unknown activity
Buspirone
Buspirone is metabolized by
CYP3A4
Buspirone levels are increased by what drugs?
Eythromycin and ketoconazole
Benzos and Barbiturates are contraindicated in what sleep disorder?
Obstructive Sleep Apnea (Pickwickian syndrome)
What drugs are hypnotics that are not used in seizure or muscle spasticity states but act on the same receptor as benzos?
The non-benzodiazapines:
Eszopiclone
zaleplon
zolpidem
