Sedative-Hypnotics Flashcards
What does hypnotic drugs do?
They produce drowsiness and encourage onset/maintenance of sleep.
What does sedative drugs do?
They DECREASE anxiety and exert calming effects.
What are the main reasons for prescribing sedative-hypnotic drugs?
To decrease anxiety and onset/maintenance of sleep.
What is the main inhibitory transmitter of the CNS?
GABA
Which part of the brain is the most affected by sedatives?
Reticular formation:because it is highly connected part, so it is sensitive.
What are the classes of drugs?
- Benzodiazepines
2. Barbiturates
How long does it take to develop tolerance for benzodiazepines?
3-5 weeks
Can ORAL benzodiazepine produce anesthesia ?
No
What drug “acts” like benzodiazepine but is NOT benzodiazepine ?
ZOLPIDEM
What is the use of ZOLPIDEM ?
Use: when somebody has difficulty falling asleep (due to it being short acting).
What drugs are benzodiazepines?
They end in “PAM” with exception to triazoLAM.
- LorazaPAM
- QuazePAM
- DiazePAM
- FlurazePAM: long acting, use: staying asleep
- TemazePAM: long acting, use: staying asleep
- TriazoLAM: short acting, use: for falling asleep
Can barbiturates produce an anesthesia effect ORALLY?
Yes
How long does it take to build tolerance to barbiturates?
2 weeks
What drugs are barbiturates?
These drugs end in ‘BARBITAL’.
- amoBARBITAL: long acting, for staying asleep
- pentoBARBITAL:short acting, for falling asleep
- secoBARBITAL:short acting, for falling asleep
What class does ALCOHOL act like but is NOT?
Barbiturates
What is another drug that does NOT fall under benzodiazepines and barbiturates but targets GABA/Cl channel?
ZolpidEM
What drugs are antihistaminics (same use as barbiturates and benzodiazepines) but does NOT target GABA/Cl channel?
They end in ‘AMINE’
- DoxylAMINE
- DiphenhydrAMINE
What receptor does benzodiazepines and barbiturates act on?
GABA receptor
What happens when GABA binds?
It open Cl channels
Do barbiturates and benzodiazepines bind to the same site?
No, they bind to different allosteric sites
Does some drugs NOT work if GABA is not present?
True, SOME do not work
What class of drugs requires GABA to be present to work?
Benzodiazepines require to be present in order to work (GABA dependent).ONLY DEPENDENT
How does the channel work for benzodiazepines?
It INCREASES FREQUENCY of channel openings at ISPSs.
Do barbiturates require GABA to be present in order to work?
No, barbiturates are both dependent AND independent (can open channel without GABA but would require higher doses than with GABA being present)
How does the channel work with barbiturates?
It INCREASES the DURATION that the channel is open
If benzodiazepines and barbiturates are present; does it cause GABA to bind better?
Yes
What is the order of action for CNS depression with iNCREASE dose of hypnotic/sedative drugs?
SHARD:Sedation (not exactly asleep)–>Hypnosis( asleep)–> anesthetic coma (can’t wake up)–> respiratory depression–> death
What happens to benzodiazepines on a graph?
It plateaus because it GABA dependent, therefore it is limited by The amount of GABA present
What happens to barbiturates on a graph?
It continues to increase/grow because it is dependent AND independent of GABA.
What is REM sleep?
REM is Rapid Eye Movement, dreaming, muscle Antonia(lost of muscle strength)
What is NREM?
It is non-rapid eye movement
What are the stages of NREM ?
N1: twitching, still awake, loss of most awareness
N2: COMPLETE loss of awareness, no eye movement, still easily awake
N3: DEEP SLEEp, sleep inertia (30 mins to fully awake), some dreaming but not vivid, parasomnias such as bed wetting,sleep walking, sleep talking, night terrors
What stage of sleep does benzodiazepines and barbiturates block?
NREM:N3
Is insomnia a disease?
No, it is a symptom usually an underlying cause of depression, alcoholism or certain medications.
What type of drug would you use for falling asleep?
Short acting hypnotics (short 1/2 life)
* Do not affect sleep architecture due short life and use of falling asleep
What type of drug would you use to stay asleep?
Long lasting hypnotics (longer 1/2 life)
What are some General side effects?
- Morning sedation (long acting drugs)
- Early morning awakening (short acting drugs)
- anterograde Amnesia (such as rohypnol- date rape drug)
- paradoxical reaction of excitation (increase anxiety, excitement, aggression) occurs in barbiturates, so it has an additive effect
- lethal overdose can occur with barbiturates
Can anterograde amnesia result in lethal overdose of barbiturates?
Yes called drug automatism
Do sedatives mimic natural sleep?
No, it reduces REM and NREM- N3
Which class has stronger effects on sleep?
Barbiturates
Is NREM-N3 affected as tolerance increases?
No, NREM-N3 stays the same and is not affected with tolerance
What results in tolerance?
Withdrawal results in tolerance and therefore temporary rebound ( no tolerance effect in N3)
Do all sedative /hypnotic drugs produce tolerance ?
Yes ALL
How to counter effects of tolerance?
- By increasing does
- by using a more potent drug
*infrequent use does NOT induce (cause) tolerance
