Pharmaceutical chemistry

Objective:

This page enlists some practice questions and answer relevant to pharmaceutical chemistry and provide the opportunity to practice..

Disclaimer

Most of the practice questions in this page are collected from a pharmaceutical chemistry book chapter (details unknown, referred for practice exams) available in internet, Google and Google AI Overview. These are for informational purposes only. For medical advice or diagnosis, consult a professional. AI responses may include mistakes. 

Pharmaceutical chemistry has moved from its early emphasis on synthesis, chemical structure and reactions to encompass many elements of pharmacology, biochemistry and molecular biology. The test items in this chapter reflect this, although a considerable effort has been made to focus on chemical aspects. Some quite elementary chemistry is also touched upon.

Directions: Each of the questions or incomplete statements below is followed by five suggested answers or completions. Select the BEST answer in each case.

1. Which of the following anti-hypertensive agents is most similar in chemical structure to hydrochlorothiazide? (diuretic)

A. hydralazine

B. methyldopa

C. guanethidine

D. diazoxide

E. reserpine

Answer: D. diazoxide

Hydrochlorothiazide is a benzothiadiazine with a sulfonamide group, a chlorine atom, and a dihydro ring, while diazoxide is a benzothiadiazine with a different structure, featuring a methyl group and a chlorine atom. Both are benzothiadiazine derivatives, but hydrochlorothiazide is a diuretic used for hypertension, while diazoxide is a vasodilator used for conditions like hypoglycemia and hypertension. 

2. Malathion' (Prioderm) was marketed in 1982 for use as a pediculicide. Chemically it is classified as a/an

A. rotenoid 

B. pyrethrin

C. hexachlorocyclohexane

D. organophosphate

E. chlorophenothane

Answer: D. organophosphate

Chemically, malathion is classified as an organophosphate insecticide. It belongs to the organophosphate family of chemicals, which are known for their use as pesticides, including insecticides and acaricides. It functions by inhibiting the enzyme acetylcholinesterase. 

Rotenoids are a class of naturally occurring compounds found in plants that are best known for their insecticidal and piscicidal (fish-killing) properties. The most famous member of this group is rotenone, which has been used for centuries to control pests on crops and to help paralyze fish for easier catching. 

A pediculicide is an insecticide or topical treatment used to kill lice, often for head lice or pubic lice. Common types include those containing pyrethrins, permethrin, dimethicone, or spinosad. Effective pediculicides typically kill both live lice and eggs, but since no treatment is 100% effective against all eggs, a second treatment is often needed 7–10 days later to kill newly hatched lice.

3. Benzalkonium chloride is a germicidal surfactant which is rendered inactive in the presence of

A. organic acids

B. gram-negative organisms

C. cationic surfactants

D. soaps

E. inorganic salts

Answer: D. soaps

Benzalkonium chloride is rendered inactive by soap because it is a cationic surfactant (positively charged), while most soaps are anionic surfactants (negatively charged), meaning they have opposite charges. When mixed, these oppositely charged molecules form inactive complexes through a process of neutralization, which prevents the benzalkonium chloride from effectively disrupting microbial cell membranes and thus losing its germicidal properties. 

4. Diphenoxylate (Lomotil) is an agent useful in the treatment of diarrhea. It is structurally similar to

A. kaolin

B. meperidine

C. phenytoin

D. pectin

E. oxalic acid

Answer: B. meperidine

Diphenoxylate is a synthetic opioid that is structurally similar to meperidine, another opioid analgesic. Both drugs have a similar chemical structure, which is why diphenoxylate has opioid-like effects and can be used to treat diarrhea by slowing intestinal motility. 

5. Chymopapain (Chymodiactin) is used for therapy of herniated lower back disks. It is a/an-

A. local anestheric

B. antibiotic

C. adrenergic beta blocker

D. proteolytic enzyme 

E. acetylcholinesterase inhibitor

Answer: (D) proteolytic enzyme

Chymopapain is a proteolytic enzyme, which means it breaks down proteins. It is used in the treatment of herniated lower back disks by injecting it into the disk to dissolve the protein material of the nucleus pulposus, reducing pressure on the spinal nerves.
A herniated (or slipped) disc occurs when all or part of a disc is forced through a weakened part of the spine.

6. Upon exposure to air, aminophylline solutions may develop-

A. crystals of theophylline

В. a gas

C. a precipitate of aminophylline

D. a precipitate of ethylenediamine

E. a straw color

Answer: (E) a straw color

Upon exposure to air, aminophylline solutions may develop a straw color due to oxidation. This change in color indicates a degradation of the drug and that the solution should not be used.
Aminophylline is used together with other medicine to treat the symptoms of asthma, bronchitis, emphysema, and other lung diseases. Aminophylline belongs to a group of medicines known as bronchodilators. 

7. Which of the following is an antinoquinoline antimalarial?

.A. chloroquin phosphate (Aralen)

B. quinacrine hydrochloride (Atabrine)

C. proguanil hydrochloride (Guanatol)

D. quinine bisulfate

E. pyrimethamine (Daraprim)

Answer: (A) chloroquine phosphate (Aralen)

Chloroquine phosphate is an aminoquinoline antimalarial drug. It works by interfering with the parasite's ability to digest hemoglobin, which is a crucial process for its survival.

8. Quinine sulfate-

A may be dissolved in water by addition of a small amount of sulfuric acid to convert it to the more soluble bisulfate

B. has a sweet, pleasant taste 

C. is official in the USP as the heptahydrate

D. is poorly absorbed from the GI tract

E. is not affected by exposure to light

9. Quinine is 

A. prepared synthetically

B. an optical isomer of quinidine 

C. legally available only on prescription

D. an aminoquinoline

E. weakly acidic

10. Paraldehyde solutions that are exposed to air rapidly become strongly acidic because paraldehyde is easily oxidized to

A. acetaldehyde

B. formaldehyde

C. carbonic acid

D. formic acid

E. acetic acid

11. Petrolatum USP is not soluble in

A. chloroform

B/ ethyl alcohol

C. ether

polon

D. benzene

E. petroleuin ether

12. Chloroform should be stored in airtight, light-resistant containers at a temperature not above 30°F. In the presence of air, sunlight or open flames, chloroform is

A oxidized to phosgene

C. convened to carbon tetrachloride

B. Unchanged

D. hydrolyzed to hydrochloric acid

E. reduced to methane

13. Reagent strips impregnated with glucose oxidase, peroxidase, and orthotolidine are dipped into urine or blood as a test for the presence of glucose. The reaction(s) that occur are

A. glucose is oxidized to CO₂, which forms carbonic acid, which turns the orthotolidine a blue color

B. glucose oxidase is redńced to glucose reductase, which converts glucose to a blue color in the presence of or-thotolidine and peroxidase

glucose is oxidized to gluconic acid and hydrogen peroxide; then hydro-gen peroxide in the presence of per-oxidase converts the orthotolidine to a blue substance

D. sucrose is oxidized by glucose oxidase to glucose, which is oxidized to glucuronic acid by peroxidase and orthotolidine to form a dye

E. Glucose oxidase and atmospheric oxygen oxidize oxidase glucose to aldehyde, which undergoes a Schiff test reaction with orthotolidine and peroxidase to yield colored compounds

14. Which of the following is specific for the measurement of glucose?

(2:280-82; 8:450-52)

A. Benedict's solution cup

B. Acetest tablets

C. Clinitest tablets

D Tes-Tape

E. Ketostix

(2:280-81-299-301; 8:Secr. 12; 8:450-52,462) bul used to reduce mersocular pressure -

15. Acetazolamide (Diamoxt is rarely the drug of choice for diuretic therapy because it

A. is too potent

Bcauses systemic acidosis and alkaline

سؤال

urine

C. is habit-forming

D. does not exhibit tachyphylaxis

E. induces enzymes, especially carbonic anhydrases (39:192, 453-56)

16.

Lactic acid is

2 oxalic a

A. ethandioic acid-

B. dihydroxysuccinic acid

2-hydroxypropionic acid La

D ethanoic acetic

" cis-bútenedioic acid

haplaic a

17. Which is not true for Mineral Oil USP?

A. an antioxidant inay be added to pre-vent peroxide formation

B. it is a mixture of liquid hydrocarbons obtained from petroleum.

C. it is immiscible with castor oil wober

8. Quinine sulfate

Answer: (a) may be dissolved in water by addition of a small amount of sulfuric acid to convert it to the more soluble bisulfate

9. Quinine

Answer: (b) an optical isomer of quinidine

10. Paraldehyde solutions

Answer: (d) formic acid

11. Petrolatum USP

Answer: (a) chloroform

12. Chloroform

Answer: (a) oxidized to phosgene

13. Reagent strips for glucose

Answer: (c) glucose is oxidized to gluconic acid and hydrogen peroxide; then hydrogen peroxide in the presence of peroxidase converts the orthotolidine to a blue substance

14. Specific for the measurement of glucose

Answer: (d) Tes-Tape

15. Acetazolamide (Diamox)

Answer: (b) causes systemic acidosis and alkaline urine

16. Lactic acid

Answer: (c) 2-hydroxypropionic acid

17. Mineral Oil USP

Answer: (c) it is immiscible with castor oil