28b - Drugs for Insomnia Flashcards
MOA of estazolam
benzodiazepine
MOA of flurazepam
benzodiazepine
MOA of quazepam
benzodiazepine
MOA of temazepam
benzodiazepine
MOA of triazolam
benzodiazepine
MOA of doxepin
antidepressant
MOA of mirtazapine
antidepressant
MOA of trazodone
antidepressant
MOA of zolpidem
benzodizepine receptor agonist
MOA of zaleplon
benzodizepine receptor agonist
MOA of eszopiclone
benzodizepine receptor agonist
MOA of ramelteon
melatonin receptor agonist
MOA of diphenhydramine
1st gen antihistamine
MOA of doxylamine
1st gen antihistamine
What are the 2 arousal pathways?
- Ach cells from upper pons, PPT and LDT activate thalamus
- activation of cerebral cortex so it can receive thalamic inputs.
- histamine from TMN
- dopamine from A10 cell group
- serotonin from dorsal and median raphe
- noradrenaline from locus coeruleus
- orexin and melanin-concentrating hormone from lateral hypothalamus (LHA)
- GABA or Ach from Basal forebrain
What drugs are approved for insomnia?
benzodiazepines, benzo receptor agonists (BRA), and melatonin receptor agonists
Which insomnia drug does NOT work on GABA receptors?
Ramelteon
What is only insomnia drug that can open GABA-A channels completely by themselves?
barbiturates at high doses
What are the subgroups of BNZ receptors and what do they each do?
BZ-1 = sedation/amnesia BZ-2 = anioxlysis BZ-3 = myorelaxation and anticonvulsant
Which BNZ subgroups do benzodiazepines act on?
all three, BZ1-3
which BNZ subgroups do BRAs act on?
only on BZ1 at normal doses
What is the longest acting BNZ?
diazepam
What is the shortest acting BNZ?
midazolam
Which BNZ has CYP 2B6 activity?
Quazepam
Which BNZ has no CYP interactions?
Temazepam
Which BNZ is the only one approved for middle of the night awakening and why?
Zolpidem because of its short period of activity
What do you give for BNZ overdose?
flumazenil, and BNZ antagonist and BzRA antagonist.
can reverse overdose, cause withdrawals
ADE of flumazenil?
withdrawals, seizures, does NOT work on barbiturates, opiates or TCAs
What are the subgroups of melatonin receptors and what do they do?
MT1 = SCN activity to induce sleep MT2 = maintains circadian rhythm MT3 = NOT involved in sleep
ADE of ramelteon?
not many. No abuse or respiratory depression
What is the only antidepressant approved for insomnia?
doxepin
Why do antidepressants work for insomnia?
seem to work thorugh H1 antagonism in tuberomamillary nucleus
ADE of antidepressants for insomnia?
suicidal ideation
CYP interactions
What are the 1st gen antihistamines? and how do they work?
diphenhydramine and doxylamine.
cross BBB to inhibit H1 and some Ach.
ADE of 1st gen antihistamines?
xerostomia, blurred vision, urine reten, high intraoc press, rapid tolerance
caution in elderly and narrow-angle gluacoma
Patient experiences anxiety, irritability, restlessness, sleep apnea, respiratory depression. What is happening?
benzodiazepene withdrawals
ADE of BNZs?
sedation, cognitive impairment, rebound insomnia