MCQs PHARMACOLOGY: Drugs Acting on Central Nervous System

25.1 The minimal alveolar concentration of an inhalational anaesthetic is a measure of its:
A. Potency
B. Therapeutic index
C. Diffusibility
D. Oil: water partition coefficient

25.2 The primary mechanism by which general anaes-thetics produce their action is:
A. Affecting receptor operated ion channels in cerebral neurones
B. Blocking voltage sensitive Na+ channels in neuronal membrane
C. Depressing metabolic activity of cerebral neurones
D. Blocking production of high energy phos-phates in the brain

25.3 General anaesthetics produce immobility in response to painful surgical stimuli by acting primarily at the:
A. Motor cortex
B. Basal ganglia
C. Thalamus
D. Spinal cord
ANSWERS
2 5 . 1 A 2 5 . 2 A 2 5 . 3D

25.4 Which general anaesthetic selectively inhibits exci-tatory NMDA receptors:
A. Thiopentone
B. Halothane
C. Desflurane
D. Ketamine

25.5 If a patient being anaesthetised with ether is uncon-scious, has regular respiration, blood pressure and heart rate are normal, corneal reflex is present and eyeballs are roving, the patient is in:
A. Stage II
B. Stage III plane 1
C. Stage III plane 2
D. Stage III plane 3

25.6 No surgical operation should be performed during the following stage of anaesthesia:
A. Stage I
B. Stage II
C. Stage III, plane 1
D. Stage III, plane 3

25.7 Which of the following is a sign of deep anaesthesia: A. Appearance of tears in eyes B. Resistance to passive inflation of lungs C. Fall in blood pressure D. Patient makes swallowing movements (p. 335, 336) 25.8 The following factor delays induction with an inhaled general anaesthetic: A. Alveolar perfusion-ventilation mismatch B. Hyperventilation C. Low blood:gas partition coefficient of the anaesthetic D. Inclusion of 5% carbon dioxide in the inha-led gas mixture (p. 336) 2 5 . 4D 2 5 . 5 B 2 5 . 6 B 2 5 . 7 C 2 5 . 8 A

· 169. Central Nervous System 163 25.9 ‘Second gas effect’ is exerted by the following gas when coadministered with halothane:
A. Nitrous oxide
B. Cyclopropane
C. Nitrogen
D. Helium

25.10 'Diffusion hypoxia’ is likely to occur only after use of nitrous oxide because it:
A. Is a respiratory depressant
B. Has low blood solubility and is used in high concentration
C. Is a very potent anaesthetic
D. Interferes with diffusion of oxygen into the tissues

25.11 Select the inhalational general anaesthetic which is metabolized in the body to a significant extent:
A. Sevoflurane
B. Isoflurane
C. Ether
D. Halothane

25.12 The following anaesthetic can be used by the open drop method:
A. Ether
B. Desflurane
C. Halothane
D. Isoflurane

25.13 The minimal alveolar concentration (MAC) of halo-thane is:
A. 75%
B. 25%
C. 7.5%
D. 0.75%

ANSWERS
2 5 . 9 A 25.10 B 25.11D 25.12 A 25.13D

25.14 The following general anaesthetic has poor muscle relaxant action:
A. Ether
B. Nitrous oxide
C. Halothane
D. Isoflurane

25.15 Select the correct statement about nitrous oxide:
A. It irritates the respiratory mucosa
B. It has poor analgesic action
C. It is primarily used as a carrier and adjuvant to other anaesthetics
D. It frequently induces post anaesthetic nausea and retching

25.16 Ether is still used as a general anaesthetic in India, specially in peripheral hospitals because:
A. It is nonexplosive
B. It is pleasant smelling and nonirritating
C. It induces anaesthesia rapidly
D. It is cheap and can be administered without anaesthetic machine

25.17 As a general anaesthetic, halothane has the follow-ing advantages except:
A. Very good analgesic action
B. Noninflammable and nonexplosive
C. Reasonably rapid induction of anaesthesia
D. Pleasant and nonirritating (

25.18 The general anaesthetic having significant cardio-depressant property is:
A. Halothane
B. Enflurane
C. Ether
D. Nitrous oxide

ANSWERS
25.14 B 25.15 C 25.16D 25.17 A 25.18 A

25.19 Select the general anaesthetic having the most marked uterine relaxant action:
A. Propofol
B. Halothane
C. Nitrous oxide
D. Ether

25.20 Malignant hyperthermia is a rare complication of use of the following anaesthetic:
A. Ketamine
B. Thiopentone sodium
C. Halothane
D. Ether

25.21 Select the general anaesthetic that is particularly suitable for outpatient surgery because of quick recovery and short-lived post-anaesthetic psycho-motor impairment:
A. Ether
B. Halothane
C. Enflurane
D. Desflurane

25.22 The following is true of sevoflurane except:
A. It induces anaesthesia rapidly
B. It is nonpungent
C. It produces prolonged postanaesthetic psy-chomotor impairment
D. It is less potent than halothane

25.23 The drug/drugs used mainly for induction of general anaesthesia is/are:
A. Thiopentone sodium
B. Fentanyl + droperidol
C. Ketamine
D. All of the above

ANSWERS 25.19 B 25.20 C 25.21D 25.22 C 25.23 A


25.24 Residual CNS depression is least marked after the use of the following anaesthetic:
A. Diazepam
B. Thiopentone sodium
C. Lorazepam
D. Propofol

25.25 The anaesthetic action of thiopentone sodium is characterised by:
A. Good muscle relaxation
B. Poor analgesia
C. Sensitization of heart to adrenaline
D. No postoperative residual CNS depression

25.26 Induction of anaesthesia with propofol is often attended by:
A. Transient apnoea
B. Sharp short lasting fall in blood pressure
C. Pain in the injected vein

D. All of the above

25.27 ‘Dissociative anaesthesia’ is produced by:
A. Ketamine
B. Fentanyl
C. Propofol
D. Both ‘A’ and ‘B’ are correct

25.28 Ketamine is the preferred anaesthetic for the follow-ing except:
A. Hypertensives
B. Trauma cases who have bled significantly
C. Burn dressing
D. Short operations on asthmatics
ANSWERS
25.24D 25.25 B 25.26D 25.27 A 25.28 A

25.29 Select the anaesthetic that increases cardiac output and blood pressure:
A. Halothane
B. Fentanyl
C. Ketamine
D. Diazepam

25.30 Intravenous fentanyl is used in balanced anaes-thesia to afford:
A. Relaxation of chest muscles
B. Analgesia
C. Unconsciousness
D. Suppression of gastric acid secretion

25.31 Use of morphine in preanaesthetic medication:
A. Is routine except in the presence of contra-indications
B. Is restricted to patients being anaesthetised with ether
C. Should be made only in combination with atropine
D. Is restricted mostly to patients in pain pre-operatively

25.32 Use of glycopyrrolate in preanaesthetic medication serves the following purposes except:
A. Prevents respiratory secretions during anaesthesia
B. Guards against reflex vagal bradycardia during surgery
C. Produces amnesia for perioperative events
D. Reduces the probability of occurrence of laryngospasm

ANSWERS
25.29 C 25.30 B 25.31D 25.32 C

25.33 The following drug is routinely used in preanaesthetic medication for prolonged operations:
A. Atropine
B. Morphine
C. Promethazine
D. Ranitidine


26.1 The following is true about actions of ethylalcohol:
A. It exerts anticonvulsant action followed by lowering of seizure threshold
B. It lowers pain threshold
C. It increases confidence and reduces number of errors
D. It increases heat production and helps to keep warm in cold weather

26.2 Effect of alcohol on sleep has the following feature:
A. It is a dependable hypnotic but is not prescribed because of abuse potential
B. It consistently improves the quality of sleep
C. It can disorganise sleep architecture
D. It suppresses sleep apnoea

26.3 Patients treated with the following drug should be cautioned not to consume alcoholic beverages:
A. Mebendazole
B. Metronidazole
C. Methimazole
D. Metamizol

26.4 Regular low-to-moderate alcohol consumption is associated with:
A. Lower incidence of coronary artery disease
B. Myocardial depression
C. Physical dependence
D. Wernicke's encephalopathy

ANSWERS

25.33D 2 6 . 1 A 2 6 . 2 C 2 6 . 3 B 2 6 . 4 A

26.5 Moderate amounts of alcohol produce the following effects except:
A. Flushing
B. Tachycardia
C. Diuresis
D. Rise in body temperature

26.6 Consumption of alcoholic beverages in moderate amounts can be allowed for the following category of subjects:
A. Epileptics
B. Patients with history of myocardial infarction
C. Gastroesophageal reflux patients
D. Pregnant women

26.7 Safe limit of daily alcohol consumption is:
A. Same for men and women
B. Relatively lower for women than for men
C. Relatively higher for women than for men
D. Less than half for women than for men


26.8 What is considered to be the safe limit of daily alcohol consumption by an adult man in the absence of contraindications and interacting drugs:
A. 20-40 ml of whisky
B. 50-100 ml of whisky
C. 120-180 ml of whisky
D. 200-300 ml of whisky

26.9 Which of the following motivating factors is the least important for the alcohol drinking habit:
A. Physical dependence on alcohol
B. Pleasurable feelings induced by alcohol
C. Attitude to relate drinking with enjoyment
D. Social belief that alcohol intoxicated subject is unmindful of his actions

ANSWERS
2 6 . 5D 2 6 . 6 B 2 6 . 7 B 2 6 . 8 B 2 6 . 9 A