Class 5 - Sleep Flashcards
Common pharmaceuticals
- Melatonin
- Zopiclone
- Zolpidem
Pharmacology is used to…
Control behavioural alterations
- Sleeplessness
- Anxiety
- Agitation
- Depression
Maintain function in dementia
- helps maintain memory, thinking, speaking skills
Benzodiazepines MOA
Depress CNS activity
- Affect hypothalamic, thalamic, and limbic system of the brain
- Potentiate the inhibitory effects of endogenous GABA, but there is a cieling effect
Benzodiazepines: Withdrawal
Insomnia, anxiety, agitation, tremor, tachycardia, anroexia
Benzodiazepines: Other
Does not increase metabolism of other drugs (fewer drug interactions)
PO route is preferred - less side effects
When drugs bind to GABA receptor, inhibitory effects of GABA are enhanced, the effects are:
Anxiety is reduced –> Wakefulness is reduced, sedation to anaesthesia –> Memory and awareness is affected, amnesia, hypnotic effect –> Neuro-excitability is reduced, anti-convulsant effect
How does the GABA receptor-chloride channel complex work
When bonzos and barbituates bind to the receptor, this opens the chloride channel inhibiting the neuron from firing
Makes the channel very negative inside and inhibits firing
Good sedative-hypnotics
Benzodiazepines potentiate GABA
- Diazepam (Valium - long actong)
- Lorazepam (Ativan - intermediate acting)
- Midazolam (versed - short acting)
Other benzo-like effects: Zopiclone
Benzodiazepines: OD Mild
Drowsiness, impaired coordiation, confusion, lethargy
Benzodiazepines: OD Serious
Ataxia (clumsy muscle mvmt), hypotonia, hypotension, respiratory depression, coma
Think LESS of everything… too LESS
Benzodiazepines: OD Serious
Ataxia (clumsy muscle mvmt), hypotonia, hypotension, respiratory depression, coma
Think LESS of everything… too LESS
Benzodiazepines: OD Rare
Cardiac arrest when combined with alcohol/other CNS depressants
Flumazenil is antidote
Benzodiazepines and enzyme inducers
Reduce effect of benzos by speeding its breakdown
Ex. Carbamazepine, phenobarbital, phenytoin, St John’s Wort
Benzodiazepines and enzyme inhibitors
Increase effect of benzos by delaying breakdown
Ex. Grapefruit (diazepam), diltiazem, verapamil, macrolide antibiotics
fluconazole, omeprazole, OC
Benzodiazepines interactions
Do not induce hepatic drug-metabolizing enxymes but additive with other CNS depressants (alcohol, opioids)
Other sedative-hypnotics
Zopiclone (Immovane) - PO, short term use for insomnia
Buspirone (Buspar) - 2nd line for general anxiety
Melatonin
- Secreted by pineal gland to maintian sleep-wake cycle
- Naturally stimulated by darkness (11pm - 3am)
- Synthetically produced to mimic melatonin
Bad sedative-hypnotics
Barbituates
- Phenobarbital (PO), pentobarbital (IV, IM), thiopental (IV)
Easy to OD, interacts with MANY drugs
Barbituates: General outline
Sedative -> hypnotic -> GA -> Deep coma -> Death
Barbituates: MOA
Enhancing and/or mimicking the effect of GABA that does NOT have a ceiling effect (WHICH IS BAD)
Very narrow therapeutic index
