1 Anxiolytics

Question 1

MOA of GABA

Answer 1

1. GABA binds to GABA-A receptors (ligand-gated ion channel)
2. Activation -> open channel -> Cl- influx into neuron
3. ↑ Cl influx, ↑ intracellular conc of -ve ions -> hyperpolarization (-70)
   (memb potential away from threshold (-55mV) to trigger AP)
4. Inhibit neuron firing producing inhibitory effect on CNS

Question 2

3 Main classes of Sedatives & Hypnotics

Answer 2

Benzodiazepines
Barbiturates
Non-benzodiazepine Hypnotics

Question 3

Explain interaction of sedatives w geriatric patients

Answer 3

slower elimination
→ longer 1/2life
→ drug accumulation
→ inc AE/toxicity

Question 4

What are the three main types of sedative-hypnotic drugs?

Answer 4

Benzodiazepine, Barbiturates, Non-benzodiazepine hypnotics

Question 5

Fill in the blank: Barbiturates act on the central nervous system by enhancing the activity of the neurotransmitter ________.

Answer 5

GABA (gamma-aminobutyric acid)

Question 6

What is the primary mechanism of action of benzodiazepines?

Answer 6

• 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.

Question 7

What is a common side effect of benzodiazepines?

Answer 7

-Drowsiness
-Dizziness
-Dec alertness
-Diplopia
-Ataxia (Imp. body movement)
-Tolerance&Dependence
(reduce dose to 10-20% per week)

• CI: respiratory depression, sleep apnea

Question 8

What is the primary mechanism of action of Barbiturates?

Answer 8

• 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

Question 9

Which type of sedative-hypnotic drugs are often used for short-term treatment of insomnia?
+ MOA

Answer 9

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

Question 10

What is the drug used as an antidote for benzodiazepines? + MOA

Answer 10

Flumazenil

Binds to benzodiazepine binding sites on GABAA receptor

Question 11

Fill in the blank: Non-benzodiazepine hypnotics are also known as ________.

Answer 11

Z-drugs

Question 12

Which type of sedative-hypnotic drugs are safer in overdose compared to barbiturates?

Answer 12

Benzodiazepines

Question 13

Describe the pharmacological difference between barbiturates and benzodiazepines in terms of their effect on GABA-A receptor subunits and resulting clinical implications.

Answer 13

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.

Question 14

How does the pharmacokinetic property of redistribution contribute to the duration of action of short-acting benzodiazepines?

Answer 14

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

Question 15

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 15

Answer: B) Buspirone

Question 16

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

Answer 16

B) Sleepwalking or complex sleep behaviors

Question 17

Which benzodiazepine is most commonly used for the treatment of acute anxiety or panic attacks?
A) Alprazolam
B) Clobazam
C) Flurazepam
D) Estazolam

Answer 17

Answer: A) Alprazolam

B) Clobazam: seizure
C) Flurazepam & estazolam: hypnotics.

Question 18

Which benzodiazepine is most commonly used for the treatment of acute anxiety or panic attacks?
A) Alprazolam
B) Clobazam
C) Flurazepam
D) Estazolam

Answer 18

Answer: A) Alprazolam

B) Clobazam: seizure
C) Flurazepam & estazolam: hypnotics.

Question 19

Which of the following drugs is classified as a Benzodiazepine?
A) Zaleplon
B) Clonazepam
C) Flumazenil
D) Primidone

Answer 19

Ans: B) Clonazepam

Benzodiazepine drugs:
Diazepam
Lorazepam
Clonazepam
Temazepam
Alprazolam
Midazolam

Question 20

Which benzodiazepine is preferred for use as a muscle relaxant?
A) Lorazepam
B) Midazolam
C) Clonazepam
D) Diazepam

Answer 20

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.

Question 21

Which of the following drugs is classified as a non-benzodiazepine hypnotic?
A) Diazepam
B) Zolpidem
C) Alprazolam
D) Clonazepam

Answer 21

B) Zolpidem

Non-benzodiazepines:
Zolpidem
Zaleplon
Eszopiclone

Question 22

Which drug is commonly used as an antidote for benzodiazepine overdose?
A) Naloxone
B) Flumazenil
C) Propranolol
D) Atropine

Answer 22

B) Flumazenil