CNS Depressants Flashcards
Pons and Medulla important for
respiration control
cardiovascular function
Reticular formation important for
control of consciousness, arousal and alertness
Selective Depressants
Sedative-hypnotics
Benzodiazepines
Barbiturates
Ethanol
Non-selective Depressants
Anti-histamines
Opioid analgesics
Sedative anxiolytics
calming effect or sedation with relief of anxiety at relatively low doses
Hypnotics
produce drowsiness and/or encourage onset and maintenance of state of sleep
What brain region is most affected with anxiety?
limbic system
hippocampus
amygdala
pre-frontal cortex
Sedative Hypnotic Benzo’s (4)
Flurazepam
Temazepam
Triazolam
Midazolam
Anxiolytic Benzo’s (5)
Alprazolam CLorazepate Diazepam Lorazepam Oxazepam
Z Drugs (3)
sleep inducers
Zolpidem
Zaleplon
Eszopiclone
Linear slope Drugs
what occurs?
barbiturates
alcohol
as dose increases, effects increase all the way up to potentially coma
not as safe
Non-linear slope drugs
what occurs?
benzodiazepines
hypnotics (newer)
plateau occurs with increasing dose
SAFER
Sedative-Hypnotics Therapeutic Uses
Relief of - anxiety, insomnia
Sedation/amnesia - medical/surgical procedures
Epilepsy/Seizure tx
Withdrawal tx
Muscle relaxation
Benzodiazepines ending?
-epam
Benzodiazepine Pharmacokinetics
Metabolism occurs mainly where?
Good absorption ORALLY
Metabolized by the LIVER - (CYP3A4)
Benzo’s with rapid metabolism, short duration, less cumulative effects (2)
Why?
Lorazepam
Oxazepam
CONVERTED TO INACTIVE GLUCURONIDES - metabolites have no activity
Benzo’s with short duration and weakly active metabolites (2)
Alprazolam
Triazolam
Influence of age on metabolism of benzo’s
Affects what pharmacokinetic values (2)?
Elderly have DECREASED PHASE I METABOLISM
Slows hepatic processing
Vd increases
Ve decreases
Which two benzo’s have AGE-INDEPENDENT elimination?
Oxazepam
Lorazepam
Mechanism of action of benzodiazepins
Potentiate effects of GABA-A receptors
Increase frequency of OPENING/CONDUCTANCE of CHLORIDE ION CHANNELS
leads to HYPERPOLARIZATION – decreased neuronal firing
Benzodiazepine Side effects/Toxicity
RESPIRATORY DEPRESSION - can be lethal if combined with other depressants
ANTEROGRADE AMNESIA
TOLERANCE - 12 to 14 days
DEPENDENCE - physical and psychological
WITHDRAWAL
Withdrawal effects cause?
How to dissipate?
all of the effects that were being suppressed by the drug return more intensely
taper off drugs slowly
5 contraindications of benzo’s
pregnancy elderly substance abuser sleep disorders when alertness is required
Major Drug INteraction of Benzo’s
ADDITIVE CNS DEPRESSION - when combined with other CNS depressants
Benzo’s Major Therapeutic Uses (2)
Anxiolytic
Sedative/Hypnotic
Flumenazil - type of drug?
MOA
Clinical use
BENZODIAZEPINE ANTAGONIST
Competitive inhibitor of BZ RECEPTOR
Counteract benzo overdose
Eszopiclone
Zolpidem
type of drug?
MOA?
Clinical use
Newer SEDATIVES
Bind selectively to BZ RECEPTOR ON GABA-A receptor and act as AGONISTS
Used primarily for INSOMNIA
Barbiturates (3)
Pentobarbital
Phenobarbital
Thiopental
Barbiturates Clinical Uses
Anesthesia - thiopental
Anticonvulsant - phenobarbital
Medically induced coma - pentobarbital
Barbiturates Pharmacokinetics
absorption/distribution varies with lipid solubility
SLOW LIVER METABOLISM
Little kidney excretion
Duration is DEPENDENT ON METABOLISM - except thiopental
Barbiturates MOA
increase DURATION OF GABA-GATED CHLORIDE CHANNEL OPENING
Hyperpolarization - neuronal inhibition occurs
Ramelteon
type of drug?
MOA?
Clinical use?
SEDATIVE
MELATONIN RECEPTOR AGONIST - MT1 and MT2 receptors
minimal abuse liability
Buspirone
type of drug?
MOA?
CLinical use?
NON-SEDATING anxiolytic
PARTIAL 5HT-1a AGONIST - reduces neuronal excitability and firing frequency, also decreases 5-HT release
anti-anxiety for individuals who need more motor skills for work
Beta blocker important for reducing MANIFESTATIONS of anxiety
Propanolol
Antihistamines (2)
Hydroxyzine
Dyphenhydramine
