Flashcards in Anxiolytics: Slattery Deck (29):
What does an anxiolytic do to a patient?
Relaxed, unconcerned with surroundings, fully functional.
What does a sedative do?
Decreases activity, calms, patient is still awake.
What does a hypnotic do?
Drowsiness, facilitates the onset and maintenance of sleep, patient may be easily aroused.
What does a general anesthetic do?
Loss of consciousness. Patient cannot be aroused.
What is the difference between Barbiturates and Benzodiazepines in terms of dose?
Barbiturates can be increased to higher than what is needed for hypnosis and may lead to a state of general anesthesia or coma.
Benzodiazepines require proportionately greater dosage to achieve depression beyond hypnosis.
Name the barbiturates.
Phenobarbital, Thiopental, Pentobarbital.
How do barbiturates work?
They increase the time that the chloride channel is open on a GABA A receptor, Hyperpolarizing the cell.
Why is it easy to push barbiturates into the coma and death stage?
They aren't very selective. They also depress the excitatory actions of Glutamate by binding to the AMPA receptor.
Which Barbiturate is really lipid soluble so it works fast?
What accounts for short duration of action of barbiturates that is useful in recovery from anesthesia?
Rapid tissue redistribution.
How are barbiturates metabolized and how does this make you take dosing into account?
Metabolized by the liver SLOWLY. The half life can be up to 5 days (Phenobarbital) so multiple dosing can lead to cumulative effects.
How are barbiturates excreted? Is it ever in an unchanged form?
Via the kidney. For some, significant percentage of the drug is excreted unchanged (Phenobarbital 25 %).
How do you treat an overdose of a Barbiturate?
IV Sodium bicarbonate (Increase urinary pH)
Describe the pharmacokinetics of Barbiturates.
Barbiturates have the ability to increase CYP450: this can decrease its own function and gives it potential for other drug interactions.
What effects do barbituates and benzodiazapines have on sleep?
Decrease time it takes to fall asleep and increase the duration of stage 2 non-REM sleep. The duration of REM and stage 4 non-Rem sleep go down.
Which barbiturate is an effective treatment for tonic-clonic seizures?
Name the Benzodiazepines.
Diazepam, Lorazepam, Triazolam, Alprazolam.
How do benzodiazepines work?
Bind GABA A receptor! Increase the frequency of the chloride channels opening.
Do bentos increase CYP450 like barbituates?
How would you describe the tolerance to benzodiazepines.
Primarly pharmacodynamic. Due to down regulation of GABA A receptors.
Sedation from benzodiazepines exerts dose-dependent Anterograde amnestic effects, what does this mean?
Inability to remember events occurring during drug's duration of action.
How do you reverse persistent post-anesthetic respiratory depression from a benzodiazepine?
Flumazenil (Benzo binding site antagonist)
Which benzodiazepine has a short half-life so you may see signs of withdrawal between doses?
What are the effects of Benzodiazepines and Barbituates on CV and respiratory function?
No adverse effects unless an underlying issue.
At toxic doses, myocardial contractility and vascular tone may be depressed but it is reversible.
Describe Zolpidem (Ambien).
Agonist to benzodiazepine binding site on GABA A receptor (selective to certain receptor subtypes).
Rapid onset, promotes sleep, no anxiolytic properties.
Clinically, what are barbituates used for?
Hypnosis, seizure control, anesthesia induction.
Clinically, what are benzodiazepines used for?
Anxiety, Insomnia, Seizures, Muscle relaxation, Pre-anesthetic.
How does Buspirone work?
Relieves anxiety by being a partial agonist at 5-HT-1a receptors and D2 receptors.
Less psychomotor effects than benzos so the patient can drive.