pharmacology 

Chapter 1-Pharmacokinetics

1. Botulinum toxin is a large protein molecule. It’s action on cholinergic transmission depends on an intracellular action within nerve endings. Which one of the following processes is best suited for permeation of very large protein molecules into cells?

(A) Aqueous diffusion
(B) Endocytosis
(C) First-pass effect
(D) Lipid diffusion
(E) Special carrier transport

2. A34-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 in- side 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

3. A 12-year-old child has bacterial pharyngitis and is to receive an oral antibiotic. She complains of a sore throat and pain on swallowing. The tympanic membranes are slightly reddened bilaterally, but she does not complain of earache. Blood pressure is 105/70 mm Hg, heart rate 100/min, temperature 37.8°C (100.1°F). Ampicillin is a weak organic acid with a pKa of 2.5. What percentage of a given dose will be in the lipid- soluble form in the duodenum at a pH of 4.5?

(A) About 1%

(B) About 10%

(C) About 50%

(D) About 90%

(E) About 99%

4. alkalization of the urine enhances the recovery from phentobarbital poisoning. This means that phenobarbital must be:

a. weak base

b. weak acid 

c. strong acid

d. strong base

5. Which agent is most favored for excretion in acid urine (pH 4)compared to alkaline urine(pH8)?

a. acetylsalicylic (acid ,pKa 3.5)

b. codeine (base,pKa 7.9)

c. diazepam(base,pKa 3.3)

d. phenytoin (acid,pKa 8.3)

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%

7. 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

8. Which statement about the development of new drugs is most correct?

(A)  Because they may cause anaphylaxis, proteins cannot be used as drugs

(B)  Most drugs fall between 100 and 1000 in molecular weight

(C)  Drugs for systemic action that are to be administered orally should be highly water soluble and insoluble in lipids

(D)  Water solubility is minimal in highly polarized (charged) drug molecules

9. Which of the following would probably not be included in an optimal phase 3 clinical trial of a new analgesic drug for mild pain?

(A) A negative control (placebo)

(B) A positive control (current standard analgesic therapy)

(C) Double-blind protocol (in which neither the patient nor immediate observers of the patient know which agent is active)

(D) A group of 1000–5000 subjects with a clinical condition requiring analgesia

(E) Prior submission of an NDA (new drug application) to the FDA

10. The receptors for most pharmacodynamic agents (excluding chemotherapeutic agents) are believed to reside in which cellular structure?

a. cytoplasm

b. lysosomes

c. surface membrane

d. nucleus

e. mitochondria