1 Anxiolytics Flashcards
MOA of GABA
- GABA binds to GABA-A receptors (ligand-gated ion channel)
- Activation -> open channel -> Cl- influx into neuron
- ↑ Cl influx, ↑ intracellular conc of -ve ions -> hyperpolarization (-70)
(memb potential away from threshold (-55mV) to trigger AP) - Inhibit neuron firing producing inhibitory effect on CNS
3 Main classes of Sedatives & Hypnotics
Benzodiazepines
Barbiturates
Non-benzodiazepine Hypnotics
Explain interaction of sedatives w geriatric patients
slower elimination
→ longer 1/2life
→ drug accumulation
→ inc AE/toxicity
What are the three main types of sedative-hypnotic drugs?
Benzodiazepine, Barbiturates, Non-benzodiazepine hypnotics
Fill in the blank: Barbiturates act on the central nervous system by enhancing the activity of the neurotransmitter ________.
GABA (gamma-aminobutyric acid)
What is the primary mechanism of action of benzodiazepines?
- Bind to modulatory sites of GABA-A.
receptor btwn α&γ subunits
inc frequency of Cl channel opening - Inc Cl influx, Hyperpolarization,
Dec neuronal firing & excitability
↓ - Anxiolytic, sedative, muscle-relaxant, anticonvulsant effects.
What is a common side effect of benzodiazepines?
-Drowsiness
-Dizziness
-Dec alertness
-Diplopia
-Ataxia (Imp. body movement)
-Tolerance&Dependence
(reduce dose to 10-20% per week)
- CI: respiratory depression, sleep apnea
What is the primary mechanism of action of Barbiturates?
- Bind to modulatory sites of GABA-A.
receptor at α or β subunits.
inc duration of GABA gated Cl- channel
opening time. - Inc Cl- influx, Hyper-polarization,
Dec neuronal firing excitability - Sedative, hypnotic effects
Which type of sedative-hypnotic drugs are often used for short-term treatment of insomnia?
+ MOA
Non-benzodiazepine hypnotics
MOA:
- Selectively bind to BZ1 site on
α1 subunit of GABA-A receptor
- Open Cl- channels, inc influx,
promoting hyperpolarization
↓
Induce sleep.
*affect sleep patterns less than benzodiazepines
*no anti-anxiety effects
What is the drug used as an antidote for benzodiazepines? + MOA
Flumazenil
Binds to benzodiazepine binding sites on GABAA receptor
Fill in the blank: Non-benzodiazepine hypnotics are also known as ________.
Z-drugs
Which type of sedative-hypnotic drugs are safer in overdose compared to barbiturates?
Benzodiazepines
Describe the pharmacological difference between barbiturates and benzodiazepines in terms of their effect on GABA-A receptor subunits and resulting clinical implications.
Benzodiazepines binds btwn Alpha & Gamma subunits on the GABA-A receptors.
↑ frequency of opening of Cl ion channels.
Barbiturates binds on the alpha or beta subunits of GABA-A receptors.↑ frequency of opening of Cl ion channels.
Therefore, barbiturates have high risk of overdose leading to coma & death.
How does the pharmacokinetic property of redistribution contribute to the duration of action of short-acting benzodiazepines?
Short acting benzodiazepines are highly lipid-soluble thus ↑ passage to BBB, ↑ onset of action.
But effects wear off quickly due to the drug redistribution from CNS to peripheral compartments, explaining the short duration of actions
Which of the following drugs is used as a first-line treatment for generalized anxiety disorder due to its low risk of dependence?
A) Diazepam
B) Buspirone
C) Zolpidem
D) Clonazepam
Answer: B) Buspirone
Which adverse effect is more likely with the use of non-benzodiazepine hypnotics like zolpidem compared to benzodiazepines?
A) Tolerance
B) Sleepwalking
C) Daytime drowsiness
D) Rebound anxiety
B) Sleepwalking or complex sleep behaviors
Which benzodiazepine is most commonly used for the treatment of acute anxiety or panic attacks?
A) Alprazolam
B) Clobazam
C) Flurazepam
D) Estazolam
Answer: A) Alprazolam
B) Clobazam: seizure
C) Flurazepam & estazolam: hypnotics.
Which benzodiazepine is most commonly used for the treatment of acute anxiety or panic attacks?
A) Alprazolam
B) Clobazam
C) Flurazepam
D) Estazolam
Answer: A) Alprazolam
B) Clobazam: seizure
C) Flurazepam & estazolam: hypnotics.
Which of the following drugs is classified as a Benzodiazepine?
A) Zaleplon
B) Clonazepam
C) Flumazenil
D) Primidone
Ans: B) Clonazepam
Benzodiazepine drugs:
Diazepam
Lorazepam
Clonazepam
Temazepam
Alprazolam
Midazolam
Which benzodiazepine is preferred for use as a muscle relaxant?
A) Lorazepam
B) Midazolam
C) Clonazepam
D) Diazepam
D) Diazepam
Explanation: Diazepam is often preferred as a muscle relaxant due to its long-acting properties and ability to reduce muscle spasticity.
A) Lorazepam & midazolam: anxiety and sedation
C) Clonazepam: seizure disorders.
Which of the following drugs is classified as a non-benzodiazepine hypnotic?
A) Diazepam
B) Zolpidem
C) Alprazolam
D) Clonazepam
B) Zolpidem
Non-benzodiazepines:
Zolpidem
Zaleplon
Eszopiclone
Which drug is commonly used as an antidote for benzodiazepine overdose?
A) Naloxone
B) Flumazenil
C) Propranolol
D) Atropine
B) Flumazenil
