Lec #6 Drugs for sleep Flashcards
neurotransmitter that induces somnolence and sleepiness
adenosine
sleep
cyclical behavior of reversible unconsciousness and immobility
name 3 negative effects of chronic insufficient sleep?
- increased risk of diabetes
- cardiovascular disease
- cancer
depressant
drug that reduces neuron activity and arousal
2 types of depressants?
- Hypnotic = a drug that induces sleep
- Stimulant = a drug that promotes wakefulness and arousal
neurotransmitters that promote wakefulness
- serotonin
-norepinephrine
-dopamine
-histamine
-orexin
action of antihistamine drugs like diphenhydramine (Benadryl) and loratadine (Claritin) on histamine receptors
- some antihistamine drugs like diphenhydramine (Benadryl) block the actions of histamine and promote sleep.
- Newer antihistamines like loratadine (Claritin) don’t cause drowsiness because they are prevented from entering the brain by the blood-brain-barrier
what are the 3 components that induce sleepiness?
- increase in adenosine levels
- decrease in levels of orexin and monoamines
monoamines
- histamine
- norepinephrine
- dopamine
- serotonin
hypnotics
drugs that promote sleep
how do hypnotics promote sleep
- reduce activity in the brain involved in consciousness and vigilance
- activate GABA receptors to reduce neuronal activity and promote sleep
GABA (gamma-hydroxybutyric)
inhibitory neurotransmitter and body’s mechanism to quiet neurons
GABA receptor
ion channel allowing chloride ions to flow into the neuron and hyperpolarize the membrane potential (less likely to fire an action potential)
barbiturates (phenobarbitral) action on GABA receptor
- agonists of GABA receptor and cause it to stay open for longer periods of time so that more ions can flow into the cell and hyperpolarize the neuron
2 reasons why barbiturates are not safe for patients to take ion their own for insomnia?
- possible to overdose, can be lethal
- can be abused and become addictive
benzodiazepines (clonazepam, lorazepam, zopiclone, and zolpidem (Ambien))
natural agonist to the GABA receptor and keep it open more frequently so more chloride ions enter when the benzo is present
difference between benzodiazepines and barbiturates
-barbiturates keep the GABA receptor longer, whereas benzodiazepines increase the frequency of GABA channel opening
-benzodiazepines are also safer than barbiturates because we have a method to reverse benzodiazepine poisoning but not barbiturate poisoning.
short-term effects of benzodiazepines
- motor and cognitive impairment
- amnesia
- reduce neuronal activity of an autonomic nervous system
- digestion impairment
how does consumption of benzodiazepines cause tolerance?
- activate the GABA receptor, the body will decrease the amount of GABA receptor to offset the actions of the drug and require more of the drug to get the same effect
how are benzodiazepines addictive?
- Benzodiazepines can be addictive because they indirectly increase the firing of dopamine neurons. They do this in a similar manner to opiates because they also quiet the neurons that normally keep dopamine levels low.
- Instead of binding to mu opiate receptors, benzo’s bind to GABA receptors; however, both drugs will lead to an indirect increase in dopamine.
action of ramelteon
melatonin receptor agonist for 2 receptors: MLT1 and MLT2
3 ways ramelteon treats insomnia?
- decreases body temperature
- decreases latency to sleep onsent
- latency to persistent sleep
parasomnias
sleep disorders that involve abnormal behaviors, movements, or experiences during sleep.
which sleep-aid causes parasomnias?
Zolpidem (ambien)- metabolized differently by men and women (prescribed at a lower dose)
