Nokea
Which statement accurately describes a drug agonist?
- A. A drug that reacts with specific receptor sites on a cell and prevents the reaction of another chemical with a different receptor site on that cell
- B. A drug that interferes with the enzyme systems that act as catalysts for different chemical reactions
- C. A drug that interacts directly with receptor sites to cause the same activity that a natural chemical would cause at that site
- D. A drug that reacts with receptor sites to block normal stimulation, producing no effect
Correct Answer: C
Rationale: Agonists are drugs that produce effects similar to those produced by naturally occurring neurotransmitters, hormones, or other substances found in the body. Noncompetitive antagonists are drugs that react with certain receptor sites, preventing the reaction of another chemical with a different receptor site. Drug-enzyme interactions interfere with the enzyme systems that stimulate various chemical reactions.
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Hypoglycemic mechanism of biguanides is:
- A. Enhance closure of ATP sensitive K+ channels
- B. Inhibits gluconeogenesis in the liver
- C. Enhance glucose absorption from gastro-intestinal tract
- D. Decrease glycolysis in the peripheral tissue
Correct Answer: B
Rationale: Biguanides like metformin inhibit hepatic gluconeogenesis, reducing blood glucose production.
Suzanne is started on paroxetine (Paxil), a selective serotonin reuptake inhibitor (SSRI), for depression. Education regarding her antidepressant includes:
- A. SSRIs may take 2 to 6 weeks before she will have maximum drug effects.
- B. Red-green color blindness may occur and should be reported.
- C. If she experiences dry mouth or heart rates greater than 80, she should stop taking the drug immediately.
- D. She should eat lots of food high in fiber to prevent constipation.
Correct Answer: A
Rationale: SSRIs require 2-6 weeks for full effect, a key patient education point.
A patient may develop neutropenia from using topical Silvadene for burns. Neutropenia is a(n):
- A. Cytotoxic hypersensitivity reaction
- B. Immune complex hypersensitivity
- C. Immediate hypersensitivity reaction
- D. Delayed hypersensitivity reaction
Correct Answer: A
Rationale: Neutropenia from Silvadene (silver sulfadiazine) is a Type II cytotoxic reaction , targeting blood cells, not immune complex , immediate , or delayed .
Amphetamine is used in
- A. Narcolepsy
- B. Psychosis
- C. Anxiety disorders
- D. Obsessive compulsive neurosis
Correct Answer: A
Rationale: Amphetamine treats narcolepsy by promoting wakefulness.
The volume of distribution (Vd) for a drug that is completely retained in the vascular compartment would be?
- A. High
- B. Low
- C. Unchanged
- D. Cannot be determined
Correct Answer: B
Rationale: A drug confined to the vascular compartment (e.g., plasma) has a low Vd, close to plasma volume (about 0.06 L/kg), indicating limited distribution.