Free Central Nervous System Drugs MCQs with Answers

• A. Myoneural junction
• B. Central
• C. Ascending reticular
• D. Red nucleus activating system

Explanation: Peripheral skeletal-muscle relaxants act at the myoneural, or neuromuscular, junction by blocking nicotinic acetylcholine receptors or…

• A. Constricted
• B. Partially dilated
• C. Normal in size
• D. Totally dilated

Explanation: The second stage of general anaesthesia is the excitement or delirium stage, in which pupils are usually dilated and may react irregularly…

• A. Procaine
• B. Xylocaine
• C. Lignocaine
• D. Bupivacaine

Explanation: Procaine is an ester local anaesthetic, whereas xylocaine (lignocaine), bupivacaine, and other listed agents are amide local anaesthetics.

• A. Alveolar exchage
• B. Pulmonary ventilation
• C. Solubility of anaesthetic in blood
• D. solubility of anaesthetic in tissue

Explanation: Low solubility of an inhalational anaesthetic in blood allows its alveolar and brain partial pressures to rise rapidly, producing quick…

• A. Martin
• B. Morton
• C. Morrison
• D. Murray

Explanation: William T. G. Morton, a dentist, publicly demonstrated ether anaesthesia in 1846. Morrison and Murray are common name-based distractors.

• A. Lignocaine
• B. Benzacaine
• C. Prilocaine
• D. Procaine

Explanation: Prilocaine can produce methemoglobinaemia because its metabolites oxidise haemoglobin iron from the ferrous to the ferric state.

• A. Propanidid
• B. Theiopentone sodium
• C. Fentany droperodol
• D. Ketamine

Explanation: Ketamine produces dissociative anaesthesia, characterised by analgesia, amnesia, and a trance-like state with relative preservation of…

• A. Spinal Cord
• B. Medulla oblonagata
• C. Medullary cortex
• D. Cerebrum

Explanation: The medulla oblongata is relatively resistant to general anaesthetics compared with the cerebrum and spinal cord.

• A. Blood solubility
• B. Cerebral blood flow
• C. Partial pressure of GA
• D. All of the above

Explanation: Rapid inhalational induction requires a quickly rising anaesthetic partial pressure in the brain, promoted by favourable blood solubility…

• A. Halothane
• B. Ketamine
• C. Enflurane
• D. Isoflurane

Explanation: Ketamine is an injectable dissociative anesthetic, whereas halothane, enflurane, and isoflurane are volatile inhalational anesthetics.

• A. Propofol
• B. Sevoflurane
• C. Flumazanil
• D. Naloxane

Explanation: Propofol is a widely used intravenous induction and general anesthetic agent.

• A. Domperidone
• B. Phenazocine
• C. Cyclizine
• D. Ondanestron

Explanation: Domperidone, cyclizine and ondansetron are antiemetic drugs acting through different receptor systems.

• A. Chlorpromazine
• B. Digitoxin
• C. Metaclopromide
• D. Scopolamine

Explanation: Digitoxin is a cardiac glycoside used in selected cardiac conditions, not an antiemetic.

• A. Domperidone blocks the D2 receptors in CTZ and upper gut
• B. Domperidone causes Dystonia
• C. Ondastran acts on selective 5 -HT3 receptors
• D. Ondastran may cause vomiting by effecting the cytotoxic antige receptors

Explanation: Ondansetron blocks 5-HT3 receptors and prevents, rather than causes, vomiting associated with cytotoxic therapy.

• A. Flunarizine
• B. Divalprox sodium
• C. Zonisamide
• D. Propanolol

Explanation: Flunarizine, divalproex sodium and propranolol are used for migraine prevention.

• A. Sedative
• B. Alkaloid
• C. Diuretic
• D. Anti hypertensive
• E. Both A & B

Explanation: Morphine is a naturally occurring opium alkaloid and a central nervous system depressant with sedative effects.

• A. Dopaminergic receptor - blocking actions
• B. Gabamimetic actions
• C. Gaba-inhibitory actions
• D. Serotonin receptor - blocking action

Explanation: Granisetron is a selective 5-HT3 serotonin-receptor antagonist that prevents serotonin-mediated nausea and vomiting, especially after…

• A. Ondensetron
• B. Metaclopromide
• C. Chlorpromazine
• D. Dicyclomine

Explanation: Ondansetron, a 5-HT3 receptor antagonist, is highly effective for acute chemotherapy-induced nausea and vomiting.

• A. Meprobamate
• B. Baclofen
• C. Diazepam
• D. Dantrolene sodium

Explanation: Meprobamate, baclofen and diazepam reduce muscle spasm through central nervous system actions.

• A. Loratidine
• B. Acrivastatine
• C. Cyclizine
• D. Terfenidine

Explanation: Cyclizine is a first-generation H1 antihistamine and commonly causes sedation and anticholinergic effects.