Clinical Pharmacology | High Yield Questions

Question 1

Maximum dose of LIDOCAINE during Liposuction tumescent technique:

Answer 1

35-55 mg/kg

The maximum acceptable dose of
lidocaine is 35–55 mg/kg when given during liposuction using the tumescent technique.

Question 2

TRUE or FALSE

Dexamethasone does not possess
any mineralocorticoid activity.

Answer 2

TRUE

Remember that as the potency and duration of action of glucocorticoids increase, there is a concomitant
decrease in their mineralocorticoid activity

Question 3

Which of the following is an effect of metoclopramide?

(A) Decreased lower esophageal sphincter tone
(B) Decreased MAC for enflurane
(C) Extrapyramidal signs
(D) Increased gastric pH
(E) Relief of intestinal obstruction

Answer 3

(C) Extrapyramidal signs

Question 4

Which of the following is a side effect of beta-adrenergic blockade?

(A) Cerebral vasodilation
(B) Decreased left ventricular filling pressures
(C) Hypokalemia
(D) Increased airway resistance
(E) Uterine relaxation

Answer 4

(D) Increased airway resistance

Question 5

Compared with the response of a normal patient, administration of a bolus dose of pancuronium (0.15 mg/kg) to a patient with cirrhosis and ascites would be associated with

(A) longer duration
(B) more rapid onset
(C) more intense block
(D) more difficult reversibility
(E) similar pharmacokinetics

Answer 5

(A) longer duration

Question 6

Compared with thiopental, methohexital is characterized by

(A) better absorption after rectal administration
(B) greater protein binding
(C) greater hepatic clearance
(D) larger volume of distribution
(E) more complete biotransformation

Answer 6

(C) greater hepatic clearance

Question 7

In a patient taking a beta-adrenergic blocker, the drug most likely to produce atrioventricular junctional block is:

(A) diltiazem
(B) fentanyl
(C) halothane
(D) nifedipine
(E) verapamil

Answer 7

(E) verapamil

Question 8

Which of the following statements concerning the metabolism of atracurium is true?

(A) It is related to cardiac output
(B) It is decreased by hyperthermia
(C) It is unaffected by increasing age
(D) It is decreased by low plasma cholinesterase activity
(E) It is decreased in renal failure

Answer 8

(C) It is unaffected by increasing age

Question 9

TRUE or FALSE

A patient with HYPERTHERMIA and ALKALOSIS will have an slow down Hoffman elimination?

Answer 9

FALSE!

Hypothermia and Acidosis slows down the Hofmann elimination

Question 10

What is the byproduct of Hofmann elimination?

Answer 10

LAUDANOSINE(A tertiary amine) and a Acrylate(Monoquaternary metabolite)

Question 11

TRUE or FALSE

A patient with hepatic cirrhosis will have an altered clearance of LAUDANOSINE?

Answer 11

FALSE!

Laudanosine is 70% excreted in the bile and the rest is via urine. Patient with biliary obstruction will have an impaired clearance of this byproduct.

Question 12

Which of the following produces higher LAUDANOSINE as a byproduct of Hofmann elimination?

A. Atracurium
B. Cis-atracurium
C. Mivacurium

Answer 12

A. Atracurium

The reason is potency. Cis-atracurium is 4-5 times more potent than atracurium thus 5 times less LAUDANOSINE is produced.

More potent means less LAUDANOSINE!

Question 13

Desflurane is delivered using a vaporizer that contains internal heaters because

(A) heat decreases the drug’s viscosity
(B) heat reduces thermal loss in the patient
(C) heat increases the drug’s oil-gas partition coefficient
(D) heat prevents fluctuations of vapor pressure
(E) it does not vaporize adequately at room temperature

Answer 13

(D) heat prevents fluctuations of vapor pressure

Question 14

During nitrous oxide anesthesia, which of the following expands most rapidly?

(A) Air bubble in the blood
(B) Air in the intestine
(C) Endotracheal tube cuff
(D) Pneumothorax
(E) Sulfahexafluoride bubble in the vitreal cavity

Answer 14

(A) Air bubble in the blood

Question 15

Compared with morphine 5 mg administered epidurally at T12, morphine 5 mg administered intravenously is associated with

(A) greater incidence of urinary retention
(B) less intense analgesia
(C) less nausea and vomiting
(D) longer duration of analgesia
(E) longer time to maximum analgesia

Answer 15

(B) less intense analgesia

Plasma morphine concentrations after rapid IV injections do not correlate closely with the drug’s pharmacologic activity, likely due to the delay in transit of morphine across the blood–brain barrier.

Cerebrospinal fluid (CSF) concentrations of morphine peak 15 to 30 minutes after IV injection and decay more slowly than plasma concentrations. As a result, the analgesic and ventilatory depressant effects of morphine may not be evident during the initial high plasma concentrations after IV administration
of the opioid.

Question 16

Spontaneously breathing enflurane at 1 MAC causes increased:

(A) airway resistance
(B) diaphragm function
(C) carbon dioxide production
(D) intercostal muscle function
(E) physiologic dead space

Answer 16

(E) physiologic dead space

Question 17

Compared with epidural administration of hydrophilic opioids, epidural administration of lipophilic opioids is associated with:

(A) earlier onset of pruritus
(B) greater motor block when combined with local anesthetics
(C) higher incidence of delayed respiratory depression
(D) lesser sensitivity to reversal of analgesia by naloxone
(E) slower onset of analgesia

Answer 17

(A) earlier onset of pruritus

Question 18

In a 35-year-old patient, which of the following is associated with an increased duration of clinical narcosis following infusion of a total dose of 10 mg/kg thiopental over three hours?

(A) Alcoholism in remission
(B) Asthma
(C) Fever
(D) Obesity
(E) Use of appetite suppressants

Answer 18

(D) Obesity

The time required for the plasma concentration of thiopental to decrease 50% after discontinuation of
a prolonged infusion (context-sensitive half-time) is lengthy.

The drug is sequestered in fat and skeletal muscle and then it reenters the circulation and prevents the plasma concentration from dropping rapidly.

Question 19

An infant was administered with Thiopental during induction of anesthesia. In comparison with adult, pediatric patients will be expected to have:

A. Rapid hepatic clearance of thiopental
is expected in infants compared with that of an adult

B. Protein binding is expected to be higher in adults relative to the matured Albumin and Alpha 1 glycoprotein

C. Recovery after large or repeated doses of
thiopental may be slower for infants and children than for adults

D. longer elimination half-time is expected in pediatric patients

Answer 19

B. No difference in protein binding is expected

In pediatric patients, the elimination half-time of thiopental is shorter than in adults.
This is due to more rapid hepatic clearance of thiopental by pediatric patients. Therefore, recovery after large or repeated doses of
thiopental may be more rapid for infants and children than for adults.

Protein binding and Vd of thiopental are not different in pediatric and adult patients.

Elimination half-time is prolonged during pregnancy because of the increased protein binding of thiopental.

Question 20

Compared with dopamine, dobutamine

(A) is more useful in patients taking monoamine oxidase inhibitors because it depends on the release of norepinephrine for its effect

(B) is more useful in patients in right heart failure because it does not increase pulmonary vascular resistance

(C) has no positive chronotropic response

(D) induces diuresis without increasing cardiac output

(E) in doses greater than 10 mcg/kg/min increases systemic vascular resistance more than similar doses of dopamine

Answer 20

(B) is more useful in patients in right heart failure because it does not increase pulmonary vascular resistance

Question 21

During anesthesia with nitrous oxide 65% in oxygen, fentanyl, and pancuronium, nitroprusside is administered to decrease arterial pressure to 85/50 mmHg. A decrease in PaO2 from 120 to 65 mmHg is most likely caused by:

(A) cyanide toxicity
(B) depressed cardiac output
(C) mild hypercarbia
(D) metabolic acidosis
(E) pulmonary vasodilation

Answer 21

(E) pulmonary vasodilation

Question 22

Nitroprusside as a vasodilator is contraindicated in MYOCARDIAL ISCHEMIA due to:

A. Coronary steal phenomenon

B. Risk of cyanide toxicity

C. Baroreceptor-mediated reflex induces Tachycardia

D. Increased risk of hypoxia due to methemoglobinemia

Answer 22

A. Coronary steal phenomenon

Unlike nitroglycerin, sodium nitroprusside is relatively contraindicated in patients with acute myocardial ischemia because the drug causes abnormal redistribution of coronary blood flow away from ischemic myocardium (a phenomenon known as CORONARY STEAL).

The SNP may increase the area of damage associated with a myocardial infarction through a phenomenon called “coronary steal.” The SNP dilates resistance vessels in non-ischemic myocardium, resulting in diversion of blood flow away from ischemic areas where collateral blood vessels are already maximally dilated. Decreases in diastolic blood pressure produced by SNP may also contribute to myocardial ischemia by decreasing coronary perfusion pressure and associated coronary blood flow.

Question 23

Which of the following metabolite is the main cause of the renal insufficiency seen in patients given NTP(Sodium Nitroprusside):

A. Cyanide

B. Thiocyanate

C. Methemoglobin

D. Sulfur

Answer 23

B. Thiocyanate

Metabolism of sodium nitroprusside produces cyanide, which binds with cytochrome
oxidase to inhibit aerobic metabolism, with hemoglobin to form methemoglobin, and with sulfur to form thiocyanate.

The latter metabolite may accumulate in patients with renal insufficiency and produce neurologic
complications including delirium and seizures.

Question 24

A 55-kg, 70-year-old woman with mild chronic renal failure is unresponsive 20 hours after an uneventful coronary artery bypass grafting procedure. Anesthetic drugs included fentanyl 3000 mcg, diazepam 35 mg, and pancuronium 20 mg.

Which of the following is the most appropriate next step in management?

A. Administration of edrophonium
B. Administration of flumazenil
C. Administration of naloxone
D. CT scan of the head
E. Measurement of core body temperature

Answer 24

B. Administration of flumazenil