Chapter 3a – Pharmacology Questions




Abstract




Pharmacology Questions





Chapter 3a Pharmacology Questions




Question 1




The following agents are examples of racemic mixtures:




  1. a. Isoflurane



  2. b. Enflurane



  3. c. Sevoflurane



  4. d. Atropine



  5. e. Levobupivacaine



Question 2




Regarding optical isomers and their properties:




  1. a. S(+)-ketamine produces less intense emergence phenomena than R(–)-ketamine



  2. b. R(–)-ketamine is three times more potent than S(+)-ketamine



  3. c. Levobupivacaine requires a higher plasma concentration to produce myocardial depression compared to bupivicaine



  4. d. Levobupivacaine is more likely to precipitate excitatory central nervous system effects compared to bupivicaine



  5. e. S-ropivacaine is more lipid soluble than bupivacaine and this results in reduced penetration of Aβ nerve fibres



Question 3




Regarding drug delivery to cells:




  1. a. The degree of ionization determines the duration of drug action



  2. b. Alfentanil has a more rapid onset of action compared to fentanyl as a result of its lipid solubility



  3. c. Aspirin has a pKa of 3, meaning that it is wholly unionized at physiological pH



  4. d. Addition of 8.4% sodium bicarbonate to 2% lidocaine raises its pH and therefore increases the speed of onset



  5. e. Bupivacaine readily crosses the placenta



Question 4




Dose–response curves and log10 dose–response curves are important tools in establishing the effective range of drug doses both in vitro and in vivo.




  1. a. Dose is on the y-axis and response is on the x-axis



  2. b. On a log10 dose–response curve, if drug A is more potent than drug B, then the curve for drug A will lie to the left of the curve for drug B



  3. c. On a log10 dose–response curve, if drug A is less efficacious than drug B, then the curve for drug B will plateau higher than the curve for drug A



  4. d. If A is an antagonist of B increasing the concentration of A will move the log10 dose–response curve of B to the right



  5. e. The action of a competitive antagonist cannot be overcome by increasing the dose of the agonist



Question 5




The definition of an agonist is an agent that can bind to a receptor and elicit a biological response. Antagonists are drugs that decrease the actions of an endogenous ligand or another drug. The following are drug–receptor interactions:




  1. a. Phenylephrine is an antagonist at α-adrenergic receptors



  2. b. Doxazosin is an agonist at α-adrenergic receptors



  3. c. Ondansetron is an antagonist at 5-HT2 receptors



  4. d. Ketamine is a competitive agonist at the NMDA receptor



  5. e. Dexmedetomidine is a selective α1-adrenergic receptor agonist



Question 6




Dose–response curves can be used to determine ED50 (effective dose 50%), as well as the toxic effect in the form of the LD50 (lethal dose 50%). The ratio of LD50:ED50 is known as the therapeutic index and can be utilized to estimate drug safety.




  1. a. For greater safety, a drug should have a low therapeutic index



  2. b. Warfarin has a high therapeutic index



  3. c. Penicillin has a low therapeutic index



  4. d. Ibuprofen has a high therapeutic index



  5. e. The units of the therapeutic index are usually mg.ml–1



Question 7




Drug–receptor interactions may result in a range of responses:




  1. a. A partial agonist occupies less than half of receptor sites, which results in a submaximal response



  2. b. An antagonist has no effect on the state of the receptor in the absence of an agonist or inverse agonist



  3. c. There is a linear relationship between efficacy and affinity



  4. d. A partial agonist can have antagonist activity



  5. e. Buprenorphine acts as an inverse agonist at the μ-opioid receptor



Question 8




Concerning G-protein-coupled receptor pharmacology:




  1. a. When activated, guanylyl triphosphate (GTP) binds the β-subunit of the trimeric G-protein



  2. b. Opiates act via stimulation of the Gi subtype of G-protein-coupled receptor (GPCR)



  3. c. Activation of the Gq subtype of GPCR results in the activation of protein kinase C



  4. d. α1-Adrenoreceptors are of the Gs subtype



  5. e. α2-Adrenoreceptors are of the Gi subtype



Question 9




Concerning response to repeated drug doses:




  1. a. Tachyphylaxis refers to the phenomenon of rapid loss of response to repeated doses of a drug



  2. b. Tolerance occurs when loss of response occurs over a longer period of administration



  3. c. Desensitization occurs when incrementally larger doses of drug are required to produce the same response



  4. d. Desensitization occurs in chronic opiate abuse



  5. e. Ephedrine displays tachyphylaxis



Question 10




Concerning acetylcholinesterase inhibitors:




  1. a. Neostigmine prolongs depolarizing neuromuscular blockade



  2. b. Edrophonium forms a carbamylated complex with acetylcholinesterase



  3. c. Edrophonium has use in the treatment of myasthenia gravis



  4. d. Acetylcholinesterase inhibitors have a treatment role in Alzheimer’s disease



  5. e. Dicobalt ededate is a suitable antidote for organophosphate poisoning



Question 11




Concerning antiarrhythmics and their effect on the action potential:




  1. a. Lidocaine prolongs the refractory period of cardiac muscle



  2. b. Flecainide has no effect on the refractory period of cardiac muscle



  3. c. Verapamil’s primary effect is on the L-type slow voltage calcium channels of the SA and AV nodes



  4. d. Amiodarone decreases the repolarization rate of the cardiac membrane



  5. e. Amiodarone is a potassium channel activator



Question 12




Regarding mechanisms of drug action:




  1. a. cAMP formed under the regulation of G proteins is broken down by the action of phosphodiesterases



  2. b. G-protein receptors consist of four subunits – two α and two β



  3. c. The GABAA receptor has a pentameric structure



  4. d. Thyroid hormones act via receptors that are part of the cell membrane



  5. e. Nitrous oxide does not act on the NMDA receptor



Question 13




Regarding adverse drug reactions:




  1. a. Type A reactions are unpredictable and usually involve the immune system



  2. b. Type B drug reactions encompass both anaphylactic and anaphylactoid reactions



  3. c. An idiosyncratic drug reaction is a predictable drug reaction that is dose dependent



  4. d. An anaphylactoid reaction is mediated by IgE antibodies



  5. e. Adverse drug reactions should be reported to the Medicines and Healthcare Products Regulatory Agency (MHRA)



Question 14




The following agents are cytochrome P450 enzyme inhibitors:




  1. a. Cyclosporin



  2. b. Amiodarone



  3. c. Grapefruit juice



  4. d. Carbamazepine



  5. e. Chronic alcohol



Question 15




The following drug combinations can potentially cause serious adverse reactions:




  1. a. Moclobemide and ephedrine



  2. b. Ramipril and diclofenac



  3. c. Warfarin and orange juice



  4. d. Bisoprolol and verapamil



  5. e. Levodopa and metoclopramide in a patient with Parkinson’s disease



Question 16




The following statements are true regarding drug action/interactions:




  1. a. A synergistic reaction occurs when the net effect of several drugs is the sum of the individual actions of each drug



  2. b. Reversal of heparin with protamine is a physicochemical interaction



  3. c. The increase in acetylcholine after neostigmine administration is an indirect pharmacodynamic interaction



  4. d. Sodium bicarbonate will make the urine more alkaline and enhance the excretion of weak acids



  5. e. β-Blockers may decrease the time to onset of fasciculation following the administration of suxamethonium



Question 17




The following drugs display zero-order kinetics:




  1. a. Aspirin



  2. b. Warfarin



  3. c. Theophylline



  4. d. Alfentanil



  5. e. Phenytoin



Question 18




Which of these drugs readily penetrate the blood–brain barrier?




  1. a. Atropine



  2. b. Glycopyrronium



  3. c. Benzylpenicillin



  4. d. Thiopentone



  5. e. Vecuronium



Question 19




Which of the following statements related to drug handling by the body are true?




  1. a. The elderly population have a reduced volume of distribution (VD)



  2. b. The presence of portocaval shunts in hepatic impairment reduces bioavailability



  3. c. Plasma protein binding tends to be higher in the neonate than in the adult



  4. d. Patients with renal impairment may have an increased VD and may require a higher loading dose of drug



  5. e. With regards to lidocaine use in the neonate, the proportion of free drug will be lower than in the adult



Question 20




The rapid onset of action of thiopentone when administered intravenously is as a result of:




  1. a. Its pKa of 7.6



  2. b. Cerebral blood flow



  3. c. Redistribution to muscle and adipose tissue



  4. d. Extensive hepatic metabolism



  5. e. Its degree of lipophilicity



Question 21




Bioavailability:




  1. a. Is greater by the enteral route than the sublingual route



  2. b. Is indicated by the area under the plasma concentration–time curve



  3. c. May be affected by coeliac disease if drugs are given orally



  4. d. Is low if a drug undergoes minimal first pass metabolism



  5. e. Is 100% if a drug is given intravenously



Question 22




The following drugs cross the placenta in significant quantities:




  1. a. Isoflurane



  2. b. Diclofenac



  3. c. Thiopentone



  4. d. Morphine



  5. e. Co-amoxiclav



Question 23




The following drugs are predominantly metabolized by the liver:




  1. a. Propofol



  2. b. Cisatracurium



  3. c. Esmolol



  4. d. Mivacurium



  5. e. Lisinopril



Question 24




The following drugs are correctly paired with a recognized mechanism by which they enter cells:




  1. a. Thiopentone and passive diffusion



  2. b. Fluconazole and active transport



  3. c. Iron and pinocytosis



  4. d. Glucose and passive diffusion



  5. e. Penicillin G and active transport



Question 25




The following drugs are efficiently removed from the plasma by haemofiltration:




  1. a. Atenolol



  2. b. Aspirin



  3. c. Enoxaparin



  4. d. Digoxin



  5. e. Warfarin



Question 26




Regarding drug elimination:




  1. a. Clearance refers to the amount of drug removed from the body per unit time



  2. b. Elimination of most drugs follows zero-order kinetics



  3. c. Elimination is often related to renal function



  4. d. Rate of elimination is influenced by volume of distribution



  5. e. A time constant is longer than a half-life



Question 27




Concerning multicompartmental pharmacokinetic models:




  1. a. Peripheral compartments represent less vascular structures



  2. b. A drug can be eliminated from any compartment



  3. c. Catenary models link a central compartment to peripheral compartments



  4. d. In three-compartment models, equilibration between central and peripheral compartments occurs at different speeds



  5. e. In a tri-exponential decay curve, the sum of the three tangents’ y intercepts is equal to concentration at the t = 0 (Co) value



Question 28




Concerning the context-sensitive half-life:




  1. a. It is defined as the time for the plasma concentration of a drug to fall by 50% subsequent to cessation of an infusion after plasma loading



  2. b. Remifentanil displays a context-insensitive half-life



  3. c. Context sensitive half-life predicts time to waking subsequent to termination of infusion of a hypnotic agent



  4. d. Alfentanil demonstrates context sensitivity after prolonged infusion times



  5. e. Fentanyl demonstrates context sensitivity after prolonged infusion times



Question 29




Concerning total intravenous anaesthesia:




  1. a. Plasma concentrations are not assessed during anaesthesia



  2. b. A dedicated cannula for anaesthesia is mandatory



  3. c. It is indicated in patients with a history of malignant hyperpyrexia



  4. d. The Schnider pharmacokinetic model is more appropriate for use in elderly patients undergoing propofol target-controlled infusion



  5. e. No adjunctive analgesia is required in anaesthesia with remifentanil and propofol



Question 30




Regarding prolonged depolarizing neuromuscular blockade (suxamethonium apnoea):




  1. a. 96% of the population is homozygous for the Eu gene



  2. b. Those with the genotype Ea:Ea may have a resultant block, which is prolonged by up to 10 minutes



  3. c. The dibucaine number refers to the direct activity of plasma cholinesterase



  4. d. Those with a homozygous normal genotype and phenotype have a dibucaine number of 20



  5. e. The alleles responsible for altered plasma cholinesterase activity have been identified on chromosome 3



Question 31




Regarding genetic differences in drug handling:




  1. a. Malignant hyperpyrexia (MH) has been associated with defects in the ryanodine receptor on chromosome 17



  2. b. A diagnosis of MH is based on the response of biopsied muscle to 2% halothane and caffeine



  3. c. Trigger agents for MH include etomidate and ephedrine



  4. d. Drugs that may be affected by acetylator status include hydralazine and isoniazid



  5. e. Up to 90% of oriental populations are ‘fast acetylators’



Question 32




Thiopentone:




  1. a. Is a methylated oxybarbiturate



  2. b. Is more protein bound than pentobarbitone



  3. c. Has a pH of 10.5 in solution



  4. d. Potentiates the α-subunit of the GABAA receptor



  5. e. May produce an isoelectric EEG



Question 33




Propofol:




  1. a. Has a calorie load of 1 kcal.ml–1



  2. b. Undergoes sulfuronidation within the liver



  3. c. Commonly precipitates a reflex tachycardia when given at induction doses



  4. d. May cause greenish discolouration of the hair



  5. e. Has a terminal elimination half-life of 5–12 hours



Question 34




Ketamine:




  1. a. May be given rectally



  2. b. Potentiates the neurotransmitter glutamate at the NMDA receptor



  3. c. Shows agonist action at OP3 receptors



  4. d. Increases cerebral blood flow



  5. e. Is metabolized to norketamine by cytochrome P450 enzymes



Question 35




Etomidate:




  1. a. Contains 35% v/v ethylene glycol in solution to improve stability



  2. b. Commonly results in histamine release on injection



  3. c. Is a hydroxylated imidazole derivative



  4. d. Inhibits the 17α-hydroxylase enzyme



  5. e. May precipitate a porphyric crisis



Question 36




Regarding thiopentone:




  1. a. Rapid emergence from a single bolus dose is due to rapid metabolism



  2. b. It may cause a reduction in urine output as a result of increased ADH release



  3. c. Anaphylactic reactions are seen in approximately 1:7500 administrations



  4. d. It produces a reduction in cerebral metabolic oxygen requirement (CMRO2)



  5. e. Solubility is dependent on tautomerism



Question 37




Regarding propofol:




  1. a. Volume of distribution is approximately 4 l.kg–1



  2. b. Epileptiform movements are seen in up to 10% of patients



  3. c. It is 80% bound to plasma albumin



  4. d. Offset is more rapid than thiopentone following an initial induction dose



  5. e. Pain on injection can be reduced by the addition of 1% lidocaine to the syringe



Question 38




Benzodiazepine metabolism involves the following reactions:




  1. a. Hydroxylation



  2. b. Acetylation



  3. c. Dealkylation



  4. d. Glucuronidation



  5. e. Oxidation



Question 39




Regarding benzodiazepines:




  1. a. They have low oral bioavailability



  2. b. They display high protein binding



  3. c. Their half-life may be prolonged due to genetic variability



  4. d. They have a small volume of distribution



  5. e. Midazolam has relatively low clearance compared to other benzodiazepines



Question 40




Metabolism of benzodiazepines occurs in the liver and there may be some active metabolites. In considering metabolism and excretion:




  1. a. Urinary excretion for benzodiazepines is in the order of 10%



  2. b. Benzodiazepines are effectively removed by dialysis



  3. c. Chlordiazepoxide has active metabolites following transformation in the liver



  4. d. Diazepam has an elimination half-life of over 24 hours



  5. e. Temazepam has no active metabolites



Question 41




Isoflurane:




  1. a. Has a molecular weight of 200



  2. b. Has an oil:gas partition coefficient of 225



  3. c. Causes greater myocardial depression than halothane



  4. d. Causes dose-dependent uterine relaxation



  5. e. Is 2% metabolized



Question 42




Concerning nitrous oxide:




  1. a. The equilibration of fractional alveolar to fractional inspired concentration (FA/Fi) is faster with desflurane compared to nitrous oxide



  2. b. It is produced by the heating of ammonium sulfate



  3. c. It reduces uterine muscle tone



  4. d. It causes megaloblastic anaemia with prolonged use



  5. e. Its use is contraindicated in patients with pneumothorax



Question 43




Concerning minimum alveolar concentration (MAC):




  1. a. MAC is decreased in hyperthyroidism



  2. b. MAC is decreased in pregnancy



  3. c. There is an inverse relationship to the oil:gas partition coefficient of agents



  4. d. The MAC of nitrous oxide is higher than that of halothane



  5. e. It is defined as a percentage of 1 atmosphere



Question 44




Concerning sevoflurane:




  1. a. Has a boiling point of 58 °C



  2. b. Has a saturated vapour pressure of 32 kPa at 20 °C



  3. c. Has an oil:gas partition coefficient of 97



  4. d. Approximately 3–5% is metabolized



  5. e. Compound A, produced from sevoflurane’s reaction with moist soda lime, is nephrotoxic in humans



Question 45




Concerning inhalational anaesthetic potency:




  1. a. There is inverse proportionality between oil:gas partition coefficients and potency



  2. b. MAC is directly proportional to potency



  3. c. Halothane is more potent than sevoflurane



  4. d. Enflurane is more potent than methoxyflurane



  5. e. Desflurane’s quick onset and offset is a reflection of its low potency



Question 46




Concerning halothane:




  1. a. It is unstable in light



  2. b. It has a saturated vapour pressure of 32 kPa at 20 °C



  3. c. It is irritant to breathe



  4. d. It increases myocardial sensitivity to catecholamines



  5. e. It is 2% metabolized



Question 47




Regarding the mechanism of action of general anaesthetics:




  1. a. The proposed mechanism is said to be consistent with the Meyer–Briggs rule



  2. b. The rule suggests the anaesthetic agent acts by dissolving in the protein bilayer of cells



  3. c. GABAA and glycine are inhibitory receptors



  4. d. Glycine receptors belong to the family of ligand-gated ion channels



  5. e. Hydrophobic anaesthetics are less potent



Question 48




Local anaesthetics are weak bases and poorly soluble. Amongst other factors, the pKa correlates to the speed of onset of a particular agent. The following are other factors that affect speed of onset of peripheral nerve blocks:




  1. a. Degree of local anaesthetic ionization



  2. b. Lipid solubility of local anaesthetic



  3. c. Proximity of anaesthetic to the target nerve



  4. d. Protein binding of the anaesthetic agent



  5. e. Type of block



Question 49




The following are the maximum recommended doses of each agent:




  1. a. Bupivacaine with epinephrine 5 mg.kg–1



  2. b. Bupivacaine without epinephrine 3 mg.kg–1



  3. c. Lidocaine with epinephrine 7 mg.kg–1



  4. d. Levobupivacaine without epinephrine 1 mg.kg–1



  5. e. Ropivacaine without epinephrine 3 mg.kg–1



Question 50




Metabolism of local anaesthetics depends on chemical structure.




  1. a. Amide local anaesthetics are rapidly metabolized by plasma cholinesterase



  2. b. Lidocaine has a low extraction ratio



  3. c. Ester local anaesthetics are rapidly metabolized in cerebrospinal fluid



  4. d. Metabolites from ester hydrolysis are excreted in the urine



  5. e. Metabolism of bupivacaine is independent of hepatic function

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Oct 24, 2020 | Posted by in ANESTHESIA | Comments Off on Chapter 3a – Pharmacology Questions
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