Anxiolytics and Sleep Flashcards
Describe the mechanism of action of benzodiazepines (BZDs).
Bind to and stimulate GABA receptors –> GABA is an inhibitory NT. They cause an influx of chloride into the cells causing hyperpolarization and a decreased ability to depolarize and activate.
Differentiate barbiturates from benzodiazepines.
Barbiturates are C-3 (BZDs are C-4) and are more toxic because they prolong, rather than potentiate GABA stimulation.
T/F: Death from BZD overdose is common.
False: Death from BZD overdose is rare unless combined with another sedative –> alcohol most common
What is the antidote for BZD overdose and what is the problem with its use?
Flumazenil –> decreases seizure threshold so should only be used when isolated BZD overdose can be confirmed
Describe the pharmacokinetics of BZDs.
They all differ in their onset, duration of action, and metabolism
State the clinical uses of BZDs.
Anxiety, agitation, antiemetic (especially in chemo), insomnia, seizures, anesthetic induction, alcohol withdrawal, muscle relaxation
Describe the process of discontinuing long-term use of BZDs.
They must be tapered over time to avoid severe withdrawal
Describe the AEs associated with BZDs and state one that can sometimes be beneficial.
Drowsiness, confusion, sluggishness, retrograde amnesia. Retrograde amnesia is beneficial in anesthesia.
Which two BZDs used for anxiety have the shortest duration of action (quick on and quick off)?
Lorazepam and Oxazepam –> these drugs are the final metabolites of other BZDs
By what routes and rough dosing are the short-acting BZDs administered?
Lorazepam - IV or PO (dosed in micro doses)
Oxazepam - PO (dosed in milligrams)
For what patients are the short-acting BZDs preferred?
Elderly and liver failure –> BZDs are lipophilic, short acting agents less toxic to liver
What is the dose limiting AE of BZDs?
Respiratory depression
Where are you likely to find agitated patients that would benefit from BZDs?
ICUs and nursing homes
What is the primary use of Alprazolam?
Panic attacks
State the father of all BZDs and describe its pharmacokinetics?
Diazepam –> longest half-life of all BZDs
What is the primary use of Temazepam and why isn’t it used much anymore?
Insomnia –> been replaced by Ambien, etc.
Describe the mechanism of action of buspirone?
Not a BZD –> serotonin antagonist. It is unknown exactly how it decreases anxiety.
What is the C schedule of buspirone?
It is not a controlled substance
What is the advantage of buspirone and what patients most benefit from its use?
No sedative effects –> can be used by bus drivers and other workers that operate machinery
Compare buspirone to BZDs regarding their efficacy as an anxiolytic.
They are as effective as BZDs but they take 3 weeks to have effect. Buspirone cannot be used acutely.
How is buspirone dosed?
TID
Describe the general treatment ladder in attempting to manage insomnia.
Improve sleep hygiene
OTC meds: diphenhydramine or melatonin
Prescription meds: non-controlled, then controlled
What medications that we have previously discussed in class can be used to treat insomnia?
Trazadone (atypical antidepressant), TCAs, Diphenhydramine
T/F: Patients are often on insomnia medications for life once they start them.
False: Patients should not be on insomnia meds for life –> treat the underlying cause (anxiety for ex)
