Insomnia

Question 1

A 45-year-old man with chronic insomnia is prescribed Zolpidem. Which of the following best describes its mechanism of action?

A. Binds to both alpha-1 and alpha-2 subunits of the GABA-A receptor to cause sedation and muscle relaxation
B. Selectively binds to alpha-1 subunit of the GABA-A receptor to promote sedation with minimal anxiolytic effects
C. Blocks histamine (H1) receptors in the brain to promote sleep
D. Antagonizes orexin receptors to suppress wake-promoting signals

Answer 1

B

Z-drugs (e.g., Zolpidem, Zaleplon, Zopiclone) selectively bind to alpha-1 subunit of GABA-A receptors, providing sedation with less anxiolytic and myorelaxant effects, compared to benzodiazepines that act on multiple subunits.

Question 2

A 60-year-old woman has both anxiety and insomnia. Which drug is most appropriate?

A. Zolpidem
B. Lorazepam
C. Diphenhydramine
D. Lemborexant

Answer 2

B

Lorazepam, a benzodiazepine, is preferred when insomnia co-exists with anxiety because of its broader GABA-A subunit binding and anxiolytic effects.
Zolpidem is not ideal as it only induces sedation without treating anxiety.
Diphenhydramine (first-gen antihistamine) is not recommended for elderly due to anticholinergic effects.
Lemborexant is useful but expensive and mainly for primary insomnia.

Question 3

Which patient is most at risk of respiratory depression when prescribed benzodiazepines?

A. 50-year-old with generalized anxiety disorder
B. 40-year-old on sertraline for depression
C. 65-year-old with obstructive sleep apnea (OSA)
D. 35-year-old with insomnia and no comorbidities

Answer 3

C

Patients with OSA, severe lung disease, or hypoventilation are at high risk for respiratory depression when given benzodiazepines or other CNS depressants.

Question 4

Clonazepam is prescribed to a patient for insomnia. Which statement is correct about its pharmacology?
A. It is short-acting with a half-life of 5-10 hours
B. It may cause morning grogginess due to its long half-life
C. It is ideal for elderly patients due to low fall risk
D. It has minimal risk of rebound insomnia

Answer 4

C

Mirtazapine causes sedation at low doses due to potent H1 histamine receptor antagonism.
At higher doses, its noradrenergic effect becomes dominant and sedation is reduced.

Question 5

A 30-year-old patient has difficulty sleeping for 1 month. Which is the first-line treatment before starting pharmacotherapy?

A. Zolpidem
B. Cognitive Behavioral Therapy for Insomnia (CBT-I)
C. Diphenhydramine
D. Low-dose sedating antidepressant

Answer 5

B

CBT-I is the gold standard and first-line treatment for insomnia.
Pharmacological agents are reserved for short-term or refractory cases.

Question 6

Which statement about sleep restriction therapy is correct?

A. Patients are encouraged to nap during the day to reduce sleep debt
B. It aims to consolidate sleep by limiting total sleep time to about 85%
C. Patients should lie in bed as long as possible to force sleep onset
D. It is used only in patients with OSA

Answer 6

B

Sleep restriction therapy limits total sleep time to ~85%, helping the brain consolidate sleep and reduce fragmented patterns. Napping is not allowed.

Question 7

A 78-year-old man with mild cognitive impairment and insomnia asks for medication. Which option is most appropriate?

A. Diphenhydramine
B. Zolpidem
C. Lorazepam
D. Clonazepam

Answer 7

B

Z-drugs like Zolpidem are preferred in elderly because they are more selective, causing less cognitive and motor impairment compared to benzodiazepines.

Antihistamines like diphenhydramine should be avoided due to anticholinergic effects and fall risk.

Question 8

A patient with a history of alcohol dependence is started on Zolpidem. Which complication is most likely?

A. Improved sleep without complications
B. Reduced anxiety symptoms
C. Increased risk of dependence and abuse
D. Lower risk of sedation compared to non-alcoholics

Answer 8

C

Patients with alcohol dependence have a higher risk of Z-drug or benzodiazepine abuse, so these drugs should be avoided or closely monitored.

Question 9

Which of the following is an advantage of lemborexant compared to benzodiazepines?

A. Higher potential for dependence
B. Causes significant next-day sedation
C. Maintains normal sleep architecture
D. Used for long-term insomnia routinely

Answer 9

C

Lemborexant, an orexin receptor antagonist, helps maintain normal sleep cycles, has less dependence potential, and minimal next-day sedation, unlike benzodiazepines.

Question 10

A patient with insomnia and depression is started on Mirtazapine. Which mechanism explains its sedative effect?

A. Blocking alpha-2 adrenergic receptors
B. Blocking orexin receptors
C. Potent H1 receptor antagonism
D. Enhancing serotonin reuptake

Answer 10

C

Mirtazapine causes sedation at low doses due to potent H1 histamine receptor antagonism.
At higher doses, its noradrenergic effect becomes dominant and sedation is reduced.