Prodrugs and soft drugs are strategic pharmaceutical innovations designed to optimize drug therapy. Prodrugs are biologically inactive compounds converted into active drugs after administration, while soft drugs are active compounds designed to undergo predictable and safe inactivation after achieving their therapeutic effect. This quiz evaluates your knowledge of their mechanisms, design, and clinical application as outlined in Pharm.D. coursework, particularly in PHA5439 and PHA5515.
1. What is a prodrug?
- A. A highly potent drug
- B. An inactive compound that is metabolized into an active drug
- C. A controlled substance
- D. A drug with multiple active metabolites
Correct answer: B. An inactive compound that is metabolized into an active drug
2. What is a soft drug?
- A. A drug with low binding affinity
- B. A drug that is activated by enzymes
- C. An active drug designed to be inactivated predictably after action
- D. A drug with low solubility
Correct answer: C. An active drug designed to be inactivated predictably after action
3. Which of the following is a major advantage of prodrugs?
- A. Slower onset of action
- B. Increased water solubility
- C. Enhanced stability in the GI tract
- D. Predictable inactivation
Correct answer: C. Enhanced stability in the GI tract
4. Which of the following is a classic example of a prodrug?
- A. Morphine
- B. Codeine
- C. Atenolol
- D. Acetaminophen
Correct answer: B. Codeine
5. What enzyme is commonly responsible for activating ester prodrugs?
- A. CYP3A4
- B. Esterases
- C. UGT
- D. SULT
Correct answer: B. Esterases
6. What is a key characteristic of soft drugs?
- A. They accumulate in tissues
- B. They undergo enzymatic activation
- C. They are designed to produce inactive metabolites
- D. They have poor oral bioavailability
Correct answer: C. They are designed to produce inactive metabolites
7. Lisdexamfetamine (Vyvanse) is an example of a prodrug used to treat:
- A. Hypertension
- B. Asthma
- C. ADHD
- D. Depression
Correct answer: C. ADHD
8. Which of the following best describes the purpose of designing prodrugs?
- A. To avoid drug resistance
- B. To enhance drug potency
- C. To improve pharmacokinetics and reduce toxicity
- D. To eliminate metabolites
Correct answer: C. To improve pharmacokinetics and reduce toxicity
9. Prednisolone is the active form of which prodrug?
- A. Betamethasone
- B. Cortisol
- C. Prednisone
- D. Dexamethasone
Correct answer: C. Prednisone
10. The concept of soft drugs is most often applied in:
- A. Oncology
- B. Dermatology and anesthesiology
- C. Psychiatry
- D. Infectious disease
Correct answer: B. Dermatology and anesthesiology
11. What is the main purpose of soft drug design?
- A. Slow drug release
- B. Prolong drug activity
- C. Achieve rapid therapeutic action and predictable metabolism
- D. Enhance CNS penetration
Correct answer: C. Achieve rapid therapeutic action and predictable metabolism
12. Which of the following is a soft drug used in ophthalmology?
- A. Dipivefrin
- B. Loteprednol
- C. Timolol
- D. Pilocarpine
Correct answer: B. Loteprednol
13. Prodrugs are often used to overcome:
- A. Low potency
- B. High bioavailability
- C. Poor taste
- D. Poor membrane permeability
Correct answer: D. Poor membrane permeability
14. Which of these is a prodrug that requires metabolic activation in the liver?
- A. Morphine
- B. Lisinopril
- C. Enalapril
- D. Amoxicillin
Correct answer: C. Enalapril
15. Which route of administration is most suitable for soft drugs?
- A. Intravenous
- B. Oral
- C. Topical
- D. Sublingual
Correct answer: C. Topical
16. What is the main enzyme responsible for converting clopidogrel to its active form?
- A. CYP2C9
- B. CYP3A4
- C. CYP2D6
- D. CYP2C19
Correct answer: D. CYP2C19
17. Which of the following is NOT a benefit of soft drugs?
- A. Reduced systemic toxicity
- B. Predictable deactivation
- C. Long half-life
- D. Fewer side effects
Correct answer: C. Long half-life
18. Valacyclovir is a prodrug of:
- A. Acyclovir
- B. Zidovudine
- C. Lamivudine
- D. Tenofovir
Correct answer: A. Acyclovir
19. Which of the following is true about inactive prodrugs?
- A. They exert immediate pharmacological effects
- B. They are more potent than their active form
- C. They require enzymatic conversion to become active
- D. They have a longer duration of action
Correct answer: C. They require enzymatic conversion to become active
20. Which soft drug is designed to reduce intraocular pressure?
- A. Loteprednol
- B. Timolol
- C. Dipivefrin
- D. Dorzolamide
Correct answer: C. Dipivefrin
21. Soft drugs are designed for which of the following purposes?
- A. Maximize systemic exposure
- B. Prevent any metabolism
- C. Minimize side effects by rapid inactivation
- D. Increase renal clearance
Correct answer: C. Minimize side effects by rapid inactivation
22. Which of the following is an example of a prodrug used in chemotherapy?
- A. Cyclophosphamide
- B. Methotrexate
- C. Fluorouracil
- D. Doxorubicin
Correct answer: A. Cyclophosphamide
23. The active form of sulfasalazine in the colon is:
- A. Mesalamine
- B. Prednisolone
- C. Acetaminophen
- D. Budesonide
Correct answer: A. Mesalamine
24. Why are ester prodrugs often used in drug development?
- A. Easier to manufacture
- B. They resist hydrolysis
- C. To improve lipophilicity and absorption
- D. To enhance taste
Correct answer: C. To improve lipophilicity and absorption
25. What class of drugs is often developed as soft drugs to reduce systemic side effects?
- A. NSAIDs
- B. Corticosteroids
- C. Antibiotics
- D. Opioids
Correct answer: B. Corticosteroids
26. Which of the following is a characteristic of ideal prodrugs?
- A. Chemically unstable
- B. Highly polar
- C. Stable until metabolized to the active form
- D. Resistant to enzymatic cleavage
Correct answer: C. Stable until metabolized to the active form
27. Which of the following best describes a “carrier-linked prodrug”?
- A. Chemically reactive compound
- B. Contains a transport system to aid absorption
- C. Linked to a chemical group that is enzymatically cleaved
- D. Drug with a long half-life
Correct answer: C. Linked to a chemical group that is enzymatically cleaved
28. Which pharmacokinetic parameter is most improved by prodrug design?
- A. Volume of distribution
- B. Bioavailability
- C. Protein binding
- D. Tmax
Correct answer: B. Bioavailability
29. Soft drug metabolism is usually:
- A. Non-enzymatic
- B. Enzyme-independent
- C. Predictable and enzyme-specific
- D. Highly variable
Correct answer: C. Predictable and enzyme-specific
30. A “mutual prodrug” involves:
- A. Two inactive drugs combined with synergistic action
- B. An active drug paired with a vitamin
- C. Combination of two drugs each acting as a promoiety for the other
- D. A drug with its antidote
Correct answer: C. Combination of two drugs each acting as a promoiety for the other
31. Remifentanil is classified as a:
- A. Prodrug
- B. Soft drug
- C. Cytotoxic drug
- D. Long-acting analgesic
Correct answer: B. Soft drug
32. What is the advantage of converting active drugs into prodrugs for oral delivery?
- A. Increases renal clearance
- B. Reduces hepatic metabolism
- C. Improves solubility and permeability
- D. Eliminates GI absorption
Correct answer: C. Improves solubility and permeability
33. Which of the following is not commonly modified in prodrug design?
- A. Functional groups
- B. Drug solubility
- C. Taste masking
- D. Half-life extension
Correct answer: D. Half-life extension
34. Which of these drugs is designed to be a soft corticosteroid?
- A. Prednisone
- B. Loteprednol
- C. Hydrocortisone
- D. Betamethasone
Correct answer: B. Loteprednol
35. The use of prodrugs in pediatric patients is mainly to:
- A. Decrease absorption
- B. Reduce metabolic rate
- C. Enhance palatability and dosing flexibility
- D. Prevent hepatic clearance
Correct answer: C. Enhance palatability and dosing flexibility
36. What is the main difference between prodrugs and soft drugs?
- A. Only prodrugs are active
- B. Soft drugs require bioactivation
- C. Prodrugs are inactive and need activation; soft drugs are active and designed to be inactivated
- D. Soft drugs are only used in oncology
Correct answer: C. Prodrugs are inactive and need activation; soft drugs are active and designed to be inactivated
37. Which of the following is true about latanoprost?
- A. It is a soft steroid
- B. It is a prodrug used to lower intraocular pressure
- C. It requires no activation
- D. It has no side effects
Correct answer: B. It is a prodrug used to lower intraocular pressure
38. Which metabolic process is crucial for prodrug activation?
- A. Filtration
- B. Enzymatic hydrolysis
- C. Passive diffusion
- D. Protein binding
Correct answer: B. Enzymatic hydrolysis
39. Which of the following is NOT a soft drug?
- A. Loteprednol
- B. Remifentanil
- C. Procaine
- D. Prednisone
Correct answer: D. Prednisone
40. A major challenge in prodrug design is:
- A. Enhancing taste
- B. Predicting rate and site of activation
- C. Avoiding bioavailability
- D. Inducing enzyme inhibition
Correct answer: B. Predicting rate and site of activation
41. What is a typical metabolic fate of soft drugs?
- A. Active metabolite formation
- B. Accumulation in adipose tissue
- C. Rapid conversion to inactive, non-toxic metabolites
- D. Persistent drug action
Correct answer: C. Rapid conversion to inactive, non-toxic metabolites
42. Bacampicillin is a prodrug of:
- A. Amoxicillin
- B. Ampicillin
- C. Penicillin G
- D. Clavulanic acid
Correct answer: B. Ampicillin
43. Which of these is most commonly added to prodrugs to improve oral bioavailability?
- A. Chloride
- B. Phosphate
- C. Sulfate
- D. Carbonate
Correct answer: B. Phosphate
44. Loteprednol is designed to minimize:
- A. Onset of action
- B. Systemic corticosteroid side effects
- C. Intraocular pressure
- D. CNS penetration
Correct answer: B. Systemic corticosteroid side effects
45. What is the role of esterases in prodrug activation?
- A. Prevent hydrolysis
- B. Oxidize prodrugs
- C. Cleave ester bonds to release active drug
- D. Transport prodrugs across membranes
Correct answer: C. Cleave ester bonds to release active drug
46. What functional group is often modified in prodrug design?
- A. Alcohols
- B. Carboxylic acids
- C. Ketones
- D. Amines
Correct answer: B. Carboxylic acids
47. Which prodrug is used to reduce gastrointestinal side effects of its active form?
- A. Levodopa
- B. Aspirin
- C. Sulfasalazine
- D. Nabumetone
Correct answer: D. Nabumetone
48. What is the most desired property of soft drugs in clinical use?
- A. Long half-life
- B. Rapid and predictable deactivation
- C. Broad spectrum activity
- D. CNS stimulation
Correct answer: B. Rapid and predictable deactivation
49. What is a key design challenge for soft drugs?
- A. Low potency
- B. Maintaining activity while allowing controlled inactivation
- C. Long metabolic pathways
- D. High molecular weight
Correct answer: B. Maintaining activity while allowing controlled inactivation
50. Which of the following represents a combination of a prodrug and a soft drug strategy?
- A. Enalapril
- B. Loteprednol
- C. Dipivefrin
- D. Remifentanil
Correct answer: C. Dipivefrin