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3# Sedatives & Hypnotics
1. Which drug class reduces anxiety WITHOUT causing sleep or drowsiness?
Hypnotics
Anxiolytics
Sedatives
Barbiturates
Explanation:
Anxiolytics reduce anxiety and tension without inducing sleep and are considered minor tranquilizers.
2. Increasing the dose of sedative-hypnotic drugs typically progresses the patient to:
Anxiety → calmness
Sleep → calmness
Sleep → anxiety
Anxiety → sedation → sleep → anesthesia
Explanation:
Dose escalation depresses CNS activity progressively from anxiety to sedation, sleep, anesthesia, and finally coma.
3. Benzodiazepines enhance GABA-A receptor activity by:
Increasing frequency of Cl⁻ channel opening
Prolonging duration of Cl⁻ channel opening
Directly opening Cl⁻ channels
Blocking NMDA receptors
Explanation:
Benzodiazepines increase the frequency of chloride channel opening and require GABA to exert their effect.
4. Which property makes benzodiazepines safer than barbiturates?
Direct GABA agonism
Selective CNS depression with wide therapeutic index
Longer half-life
Higher enzyme induction
Explanation:
Benzodiazepines cause selective CNS depression and have a wider therapeutic index than barbiturates.
5. Which benzodiazepine effect is mediated mainly by α1-containing GABA-A receptors?
Anxiolysis
Muscle relaxation
Anterograde amnesia
Autonomic suppression
Explanation:
α1-GABA-A receptors mediate sedation, hypnosis, and anterograde amnesia.
6. Which benzodiazepine is preferred for VERY short procedures (<30 min)?
Diazepam
Midazolam
Clonazepam
Remimazolam
Explanation:
Remimazolam is ultra-short acting and FDA-approved for procedures lasting ≤30 minutes.
7. First-line acute management of status epilepticus includes:
IV lorazepam
Phenobarbital orally
Zolpidem
Ramelteon
Explanation:
IV benzodiazepines (lorazepam or diazepam) are first-line for acute status epilepticus.
8. Which condition is treated with benzodiazepines to prevent withdrawal seizures?
Opioid withdrawal
Alcohol withdrawal
Benzodiazepine overdose
Serotonin syndrome
Explanation:
Diazepam and chlordiazepoxide reduce seizure risk in alcohol withdrawal syndrome.
9. Tolerance to benzodiazepines develops mainly to which effect?
Anxiolysis
Muscle relaxation
Sedative-hypnotic effect
Anticonvulsant effect
Explanation:
Tolerance develops mainly to sedative and hypnotic effects, not anxiolysis.
10. Which feature distinguishes benzodiazepine overdose from opioid overdose?
Respiratory depression
Hypotension
Loss of consciousness
Absence of miosis
Explanation:
Benzodiazepine overdose does NOT cause miosis, unlike opioid overdose.
11. Antidote for benzodiazepine overdose is:
Flumazenil
Naloxone
Activated charcoal
Atropine
Explanation:
Flumazenil is a competitive GABA-A receptor antagonist used to reverse benzodiazepine effects.
12. Which barbiturate is preferred for refractory status epilepticus?
Thiopental
Phenobarbital
Pentobarbital
Butalbital
Explanation:
Phenobarbital is used when seizures are refractory to first-line therapy.
13. Which barbiturate is used for induction of anesthesia due to ultra-short action?
Phenobarbital
Pentobarbital
Thiopental
Amobarbital
Explanation:
Thiopental is highly lipid-soluble with rapid onset (<30 sec), used for anesthesia induction.
14. Management of barbiturate overdose includes all EXCEPT:
Mechanical ventilation
Urine alkalinization
Gastric decontamination
Specific antidote administration
Explanation:
There is NO antidote for barbiturate toxicity; management is supportive only.
15. Z-drugs produce hypnotic effects by selectively binding:
α1-GABA-A receptors
α2-GABA-A receptors
NMDA receptors
Melatonin receptors
Explanation:
Z-drugs selectively target α1-GABA-A receptors, producing sedation only.
16. Which effect is NOT produced by Z-drugs?
Sedation
Muscle relaxation
Sleep induction
Reduced sleep latency
Explanation:
Z-drugs lack anxiolytic, anticonvulsant, and muscle-relaxant effects.
17. Ramelteon promotes sleep by acting on:
GABA-A receptors
Histamine H1 receptors
α1-adrenergic receptors
MT1 and MT2 melatonin receptors
Explanation:
MT1 promotes sleep onset, while MT2 regulates circadian rhythm.
18. Which hypnotic is safest for long-term use with no dependence?
Diazepam
Zolpidem
Ramelteon
Diphenhydramine
Explanation:
Ramelteon has no tolerance, dependence, or rebound insomnia and preserves sleep architecture.
19. First-generation antihistamines induce sleep mainly via:
Central H1 receptor blockade
GABA potentiation
Melatonin receptor stimulation
Serotonin inhibition
Explanation:
CNS H1 blockade causes sedation; anticholinergic effects explain many side effects.
20. Which adverse effect is MOST concerning in elderly patients using sedative-hypnotics?
Constipation
Dry mouth
Headache
Cognitive impairment and falls
Explanation:
Elderly patients are highly susceptible to confusion, impaired coordination, and falls.