PTCB Pharmacology for Technicians 2 — Questions and Answers
Question 1: Which drug interaction occurs between warfarin and vitamin K?
- Synergistic — increases anticoagulation
- Antagonistic — vitamin K reduces warfarin's effectiveness (Correct answer)
- Additive — equal effects
- Potentiation — vitamin K increases INR
Correct answer: Antagonistic — vitamin K reduces warfarin's effectiveness
Vitamin K antagonizes warfarin by providing the substrate warfarin works to deplete, reducing anticoagulant effect and lowering INR.
Question 2: What is the term for the time it takes for a drug's plasma concentration to decrease by 50%?
- Peak time
- Half-life (Correct answer)
- Onset of action
- Duration of action
Correct answer: Half-life
The half-life (t½) is the time required for the drug concentration in the plasma to decrease by half, determining dosing intervals.
Question 3: Which of the following is a potential side effect of long-term corticosteroid use?
- Hypoglycemia
- Hyperkalemia
- Osteoporosis (Correct answer)
- Hypothyroidism
Correct answer: Osteoporosis
Long-term corticosteroid use can cause osteoporosis by inhibiting osteoblast activity and increasing calcium excretion.
Question 4: Insulin glargine is classified as which type of insulin?
- Rapid-acting
- Short-acting (regular)
- Intermediate-acting (NPH)
- Long-acting (basal) (Correct answer)
Correct answer: Long-acting (basal)
Insulin glargine (Lantus, Basaglar) is a long-acting basal insulin with a duration of approximately 24 hours.
Question 5: Which drug class can cause photosensitivity as a side effect?
- Beta-blockers
- ACE inhibitors
- Tetracycline antibiotics (Correct answer)
- Calcium channel blockers
Correct answer: Tetracycline antibiotics
Tetracycline antibiotics (e.g., doxycycline) frequently cause photosensitivity, increasing the risk of sunburn.
Question 6: What is the mechanism of action of benzodiazepines?
- Block dopamine receptors
- Enhance GABA activity in the CNS (Correct answer)
- Inhibit serotonin reuptake
- Block NMDA receptors
Correct answer: Enhance GABA activity in the CNS
Benzodiazepines enhance the effect of GABA (gamma-aminobutyric acid) at GABA-A receptors, producing sedation and anxiolysis.
PTCB Pharmacology for Technicians 2
Which drug interaction occurs between warfarin and vitamin K?