HD 9 – Anxiolytics and Hypnotics Flashcards
What types of hypnotics are there?
- Benzodiazepines
- Antihistamines
- Miscellaneous
- (Barbiturates) = old fashioned
What types of insomina are there?
- Initial insomnia – struggle to sleep initially
* Early morning wakening – associated with depression
What 2 types of sleep are there and what is there percentages?
75% Non-Rapid Eye Movement (NREM)
25% Rapid Eye Movement (REM)
What types of NREM subtypes are there?
- N1 - Light sleep
- N2 - Asleep
- N3 - Best sleep- muscles relax, energy restored, BP, RR decrease
- N4 Delta wave = DEEP SLEEP (signals to/from thalamus)
What happens to REM and NREM in drug-induced sleep?
Increased NREM, decreased REM
What happens in REM sleep?
- Dreaming, body relaxed and immobile
* Provides energy and supports daytime performance
What are the effects of BZDs?
- Hypnotic – induce sleep
- Anxiolytic
- Anticonvulsant – prevent seizures (i.e. epilepsy)
- Muscle relaxant
- Amnesic – can’t remember anything after taking
- Fantasies
If patient having masseteric spasms what can be prescribed?
May prescribe BDZ to prevent this 2mg TDS (MAX)
When would temazepam be used and why?
Used in hospitals at night for initial insomnia due to short half life
When would loprazolam be used and why?
Used to lessen hangover, street drug due to short half life
When would nitrazepam be used and why?
Afternoon surgery inpatients for early morning wakening due to longer half life
When would BZDs be used in insomnia case?
- Insomnia associated with daytime anxiety – diazepam given at night
- Only when insomnia is severe
What is the BZD withdrawal like?
- Slow = want to avoid rebound insomnia and anxiety
* Rebound effects are worst after acute withdrawal of short acting drugs – need to tail individual off it
What are the 3 sites of action of BZDs?
- Reticular Activating System - controls conscious, alert state (hypnotic effect)
- Limbic system in cortex - controls emotions (anxiolytic effect)
- Other sites in cortex - anticonvulsant effect
What is the MOA of BZDs?
Influence GABA at Cl channel = increase frequency of opening of the channel
What are the side effects of BZDs?
Dependence & potentiation of other CNS depressants
What is the effect of midazolam and methadone?
Midazolam (sedative) potentiated by methadone (opiate which decreases heroin /opioid withdrawals) = may induce RESPIRATORY ARREST
What is the reversal drug for BZDs?
Flumazenil – antagonist, stronger binding than other benzodiazepines
What receptor do antihistamines block?
H1 blockers (anti-allergy) produce CNS depression at therapeutic doses
What antihistamines are used in children?
Promethazine
What are Z drugs (hypnotics) used for and name 2?
- Zolpidem
- Zopiclone = prescribed for insomnia instead of temazepam usually due to street value/ addiction of temazepam
- Work at BZD receptors
Name hypnotics?
• Chlormethiazole • Chloral hydrate • Melatonin • Alcohol N20 = LAUGHING GAS
- Diazepam
- Chlordiazepoxide
- Lorazepam
- Midazolam
- Temazepam
What is the use of anxiolytics?
- Pre-med
- Sedation
- Muscle relaxants – TMD, dislocation
- Severe pain e.g. MI
- Emergency Drugs e.g. epilepsy
- Amnesic effect – dangerous medico-legally
What is the sedative effect of alcohol?
60 mins of sedation
30 mins to peak plasma levels – variation
What effect does alcohol have on sleep?
Not good sleep inducing agent
Name anxiolytics?
Alcohol
BZDs
Buspirone
Beta-adrenergic blockers
What effect does chlordiazepoxide (BZD) have?
Reduces alcohol/drug withdrawals
What determines how long a person stays drunk for?
Acetylation in the liver
When is buspirone used?
Pt. needs anxiety helps short term for single occasion
What receptor does buspirone act on? and what effect does it cause on the body?
Acts as a serotonin receptor agonist
Anxiolytic without sedation
No withdrawal effects
What dental/oral problem does busprione cause?
Dry mouth
What are the effects of beta-adrenergic blocking drugs?
- Treats somatic anxiety e.g., tremor/ palpitations, not thoughts
- Sympathetic over-stimulation
- Low dose beta blocker – reduces sympathetic effect decreasing HR/ tremor
