Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
29 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What is the receptor of benzodiazepines?
|
GABAa receptor-Cl- ion channel macromolecular complex
|
Increases frequency of GABA-mediated Cl- ion opening (inhibitory)
|
|
|
Wheare are BZ receptors located?
|
Thalamus, limbic structures, cerebral cortex
|
|
|
|
What is a BZ antazonist?
|
Flumazenil
|
Reverses the CNS effects of benzodiazepines
Not effective against barbiturates Effective against hypnotics |
|
|
What is the receptor of barbiturates?
|
GABAa receptor (different site than benzodiazepines)
|
Increases duration of GABA-mediated Cl- ion opening (inhibitory)
May also block excitatory transmitter glutamate At high concentrations may block Na channels |
|
|
Where does Barbiturate activity occur in the CNS?
|
Midbrain reticular formation
|
Depresses neuronal activity, facilitating and prolonging inhibitory effects of GABA and glycine
|
|
|
What is the receptor of hypnotics (zolpidem, zaleplon, eszopiclone)
|
Interact with certain BZ receptors (BZ1 subtypes)
|
Bind very specific GABAa receptor isoforms (alpha1 subunits)
|
|
|
What is the range of effect of sedative-hypnotics?
|
Dose-dependent effect
Sedation/anxiolysis --> Hypnosis --> Anesthesia --> Coma |
Depressant effects are additive when 2 or more drugs are given together
|
|
|
What is the effect of sedative-hypnotics on sedation?
|
Sedative action with relief of anxiety occur with all drugs in this class
Occurs at lower doses |
Anxiolysis usually accompanied by some impairment in psychomotor functions
Behavior disinhibition may occur (can realease punishment-suppressed behavior) |
|
|
What is the effect of sedative-hypnotics on hypnosis?
|
Can promote sleep onset and increase duration of sleep state
|
REM sleep decreased at high doses
Rebound increase in REM sleep may occur on withdrawal from chronic drug use |
|
|
What is the effect of sedative-hypnotics on anesthesia?
|
Occurs at high doses of most older sedative-hypnotics
- Most barbiturates (Thiopental) - Some benzodiazepines (Midazolam) |
See amnesia and suppression of reflexes
Anterograde amnesia more likely with Benzodiazepines |
|
|
What is the effect of sedative-hypnotics on anticonvulsant actions?
|
Suppression of seizure activity occurs with most of the barbiturates and some of the benzodiazepines
|
Usually at cost of marked sedation
Selective anticonvulsant action occurs with only a few drugs (phenobarbital, clonazepam) Used in status epilepticus (IV diazepam, lorazepam, phenobarbital) - heavy sedation desirable at this point |
|
|
What is the effect of sedative-hypnotics on muscle relaxation?
|
Relaxation of skeletal muscle only occurs with high doses of most sedative-hypnotics
Diazepam effective at sedative dose levels for specific spasticity states (cerebral palsy) Meprobamate some selectivity as a muscle relaxant |
|
|
|
What is the effect of sedative-hypnotics on medullary depression?
|
High doses of conventional sedative-hypnotics (alcohols, barbiturates) cause depression of medullary neurons
|
Can lead to respiratory arrest, hypotension, cardiovascular collapse
Cause of death in suicidal overdose |
|
|
What is the effect of sedative-hypnotics on tolerance/dependence?
|
Tolerance occurs when sedative-hypnotics used chronically or in high doses
Physiological dependence occurs frequently with most sedative-hypnotics |
Cross-tolerance can occur among different chemical subgroups
Withdrawal upon discontinuation of drug (anxiety, tremors, hyperreflexia, seizures) occur most often with shorter acting drugs Less dependence with hypnotics (zolpidem, zalplon, eszopiclone) |
|
|
How is Lorazepam metabolized?
|
Extrahepatic conjugation
Inactive metabolites |
Short 1/2 life
|
|
|
How is Diazepam metabolized?
|
Hepatic metabolism
Active metabolites |
Long 1/2 life
Several days of therapy can lead to accumulation of active metabolites and excessive sedation |
|
|
How is Oxazepam metabolized?
|
Extrahepatic conjugation
Inactive metabolites |
Short 1/2 life
|
|
|
How is Flurazepam metabolized?
|
Hepatic metabolism
Active metabolites |
Long 1/2 life
Several days of therapy can lead to accumulation of active metabolites and excessive sedation |
|
|
Which sedative-hypnotics are used to treat anxiety states?
|
Benzodiazepines favored
- Alprazolam, Clonazepam Used in acute anxiety states and rapid control of panic attacks |
Antidepressants are more commonly being used as treatment of choice
|
|
|
Which sedative-hypnotics are used to treat sleep disorders?
|
Benzodiazepines (Estazolam, Flurazepam, Triazolam) used for primary insomnia
Hypnotics (Zolpidem, Zaleplon, Eszopiclone) - have less daytime cognitive impairment than BZs |
Lower doses should be used in elderly patients (more sensitive to the CNS depressant effects)
Not recommended for breathing-related sleep disorders |
|
|
Which sedative-hypnotics are used to treat withdrawal from ethanol or other sedative-hypnotics?
|
Longer-acting benzodiazepines (chlordiazepoxide, diazepam)
|
|
|
|
What are indications for the use of diazepam?
|
Anesthesia protocols
Treatment of muscle spasticity (cerebral palsy) Withdrawal from ethanol, other sedative-hypnotics |
|
|
|
What are signs of sedative-hypnotic toxicity?
|
Psychomotor dysfunction (cognitive impairment, decreased psychomotor skills, unwanted daytime sedation, sleep driving)
CNS depression Respiratory and cardiovascular depression |
Psychomotor dysfunction more common with long-acting benzodiazepines (diazepam, flurazepam), but may occur with a single dose of a short-acting benzodiazepine (triazolam). More common in elderly patients
CNS depression (occurs when used with other drugs in the class, ethanol, antihistamines, antipsychotic drugs, opioid analgesics, TCAs Respiratory/Cardiovascular depression more likely to occur with alcohols, barbiturates, and carbamates than with BZs or the newer hypnotics |
|
|
What is treatment for sedative-hypnotic overdose?
|
Flumazenil can reverse CNS depressant effects from BZs, eszopiclone, zolpidem, and zaleplon
|
Flumazenil not effective in overdose from Barbiturates, carbamates, alcohols
|
|
|
What is the indication for Buspirone?
|
GAD
|
|
|
|
What are the effects of Buspirone?
|
Selective anxiolytic
- minimal CNS depressant effects - no anticonvulsant or muscle relaxant properties Partial agonist of 5-HT1A Slow onset of action (>1 week) Minimal tolerance with chronic use |
Side effects: tachycardia, paresthesias, pupillary constriction, GI distress
|
|
|
What is the indication of Ramelteon?
|
Insomnia
|
|
|
|
What are the effects of Ramelteon?
|
Hypnotic drug
Activates melatonin receptors in the suprachiasmatic nuclei of the CNS Decreases latency of sleep onset with minimal rebound insomnia or withdrawal symptoms |
Hepatic metabolism
Active metabolite Side effects: dizziness, fatigue, endocrine changes (decreased testosterone, increased prolactin) |
|
|
What is the indication for Clonazepam?
|
Seizure disorder
Bipolar disorder Agoraphobia |
|
