I General Principles of Pharmacology

Questions: I-1 Pharmacokinetics

Difficulty level: Easy

1. A 22-year-old woman suffering from asthma was prescribed albuterol by inhalation. Albuterol is a bronchodilating drug with a molecular weight of 239 daltons. Which of the following permeation processes most likely accounted for the transfer of the drug through the bronchial mucosa?

A. Aqueous diffusion

B. Lipid diffusion

C. Facilitated diffusion

D. Endocytosis

E. Active transport

Difficulty level: Easy

2. A 34-year-old man on vacation in Mexico was admitted to the hospital because of vomiting, double vision, and muscular paralysis. The man reported that he had eaten some canned food from a local vendor the previous day. After a physical examination, a presumptive diagnosis of botulism was made. It is known that botulinum toxin causes paralysis by getting inside the axon terminals of motor nerves, where it inhibits the release of acetylcholine. Botulinum toxin is a protein with a molecular weight greater than 100,000 daltons. Which of the following permeation processes most likely accounts for the transfer of the toxin through the nerve cell membrane?

A. Aqueous diffusion

B. Lipid diffusion

C. Facilitated diffusion

D. Endocytosis

E. Filtration

Difficulty level: Easy

3. A 51-year-old woman suffering from hyperthyroidism was administered an oral solution of radioactive iodine to destroy her thyroid gland. Which of the following permeation processes most likely accounted for the transfer of the drug across the thyroid cell membrane?

A. Active transport

B. Lipid diffusion

C. Facilitated diffusion

D. Endocytosis

E. Aqueous diffusion

Difficulty level: Easy

4. A 12-year-old boy recently diagnosed with type 1 diabetes started a therapy with two daily subcutaneous administrations of insulin. Which of the following permeation processes best explains the absorption of insulin from the site of injection?

A. Bulk flow transport

B. Lipid diffusion

C. Facilitated diffusion

D. Endocytosis

E. Active transport

Difficulty level: Hard

5. An 85-year-old man was recently admitted to a nursing facility. Diseases listed in his medical record on admission were depression with anxiety symptoms, atrial fibrillation, chronic obstructive pulmonary disease, and osteoarthritis. Medications taken orally by the patient included the following:

Sertraline (base, pKa = 9.5)

Diazepam (base, pKa = 3.0)

Amiodarone (base, pKa = 7.4)

Theophylline (acid, pKa = 8.8)

Ibuprofen (acid, pKa 4.8)

Shortly after administration, which of the following drugs was most likely concentrated inside the patient’s gastric cells?

A. Sertraline

B. Diazepam

C. Amiodarone

D. Theophylline

E. Ibuprofen

Difficulty level: Medium

6. A 17-year-old boy took a tablet of naproxen for a headache. Naproxen is a weak acid with a pKa of 5.2. What percentage of the drug was most likely water soluble in the patient’s plasma?

A. 1%

B. 24%

C. 50%

D. 76%

E. 99%

F. > 99%

Difficulty level: Medium

7. A 69-year-old woman was brought to a local hospital emergency department by her son, who reported that his mother was found lethargic, disoriented, and combative a few hours earlier. Additional history revealed that she had ingested a large number of aspirin tablets in a suicide attempt. An appropriate therapy was instituted, which included the administration of sodium bicarbonate to increase the elimination of salicylate. Which of the following best explains the mechanism of this increased elimination?

A. Decreased tubular active transport of salicylate

B. Decreased renal biotransformation of salicylate

C. Decreased bioavailability of salicylate

D. Urinary ion trapping of salicylate

E. Increased glomerular filtration of salicylate

Difficulty level: Medium

8. A 63-year old man recently diagnosed with hypertension started a therapy with hydrochlorothiazide, one tablet daily. Hydrochlorothiazide is an acidic drug with a pKa of about 9. Which of the following parts of the digestive tract most likely represents the main site of absorption of that drug?

A. Oral mucosa

B. Stomach

C. Small intestine

D. Colon

E. Rectum

Difficulty level: Easy

9. The pharmacokinetic properties of five new drugs (P, Q, R, S, and T) were studied in healthy volunteers. The same dose of each drug was administered intravenously (IV) and orally to the same subject on two separate occasions. The results were the following:

Abbreviations: AUC, area under the curve; IV, intravenous.

Which of the following drugs most likely has the highest oral bioavailability?

A. Drug P

B. Drug Q

C. Drug R

D. Drug S

E. Drug T

Difficulty level: Easy

10. During a phase 1 clinical trial, four different oral dosage forms of the same dose of a drug were administered to a healthy volunteer on four separate occasions. The plasma concentration−time curves are plotted below.

Which of the following features best explains why formulation W produces the largest plasma concentration−time curve of the drug?

A. Highest absorption through gut wall

B. Lowest first-pass effect

C. Lowest hepatic clearance

D. Highest volume of distribution

E. Lowest drug elimination

Difficulty level: Easy

11. A 26-year-old man became inebriated after drinking several glasses of alcoholic beverages at a party. Ethanol is a polar, nonionizable drug with an approximate molecular weight of 46 daltons. Which of the following permeation processes mediated the man’s intestinal absorption of ethanol?

A. Aqueous diffusion

B. Bulk flow transport

C. Facilitated diffusion

D. Active transport

E. Endocytosis

Difficulty level: Hard

12. A 44-year-old man took a large dose of acetaminophen in aqueous solution to treat an excruciating headache. Two hours later, the pain was not diminished. Because acetaminophen should be effective in about 30 minutes after its oral administration, which of the following conditions most likely delayed the oral absorption of the drug in this patient?

A. A moderate increase in intestinal peristalsis

B. The presence of strong pain

C. The administration of the drug in aqueous solution

D. A large volume of distribution of the drug

E. A very low clearance of the drug

Difficulty level: Medium

13. A 22-year-old woman was admitted to the emergency department after a car accident. The woman had extensive brain trauma and multiple fractures. She complained of severe pain, and the attending physician planned to administer morphine. The physician knew that the dose should be carefully titrated because the entry of morphine into the patient’s central nervous system (CNS) was most likely higher than normal. Which of the following factors is most likely to have increased morphine entry into the CNS of this patient?

A. The high first-pass effect of the drug

B. The brain trauma of the patient

C. The young age of the patient

D. The low clearance of the drug

E. The high ionization of the drug

Difficulty level: Easy

14. A 67-year-old woman recently diagnosed with atrial fibrillation started treatment with atenolol, 100 mg/d. With this dose, the percentage of atenolol bound to plasma proteins is about 5%. Which of the following would have been the bound percentage of atenolol if a...