Nokea
Which one of the following is a fundamental difference between competitive and noncompetitive antagonist?
- A. Competitive and non competitive work on different receptors
- B. Competitive antagonist reduces agonist potency (increase EC50) and non competitive antagonist reduces agonist efficacy (decrease E max)
- C. There is no difference between them, they are exactly the same
- D. Non competitive antagonist causes an upward shift of the E max while competitive antagonist does the opposite
Correct Answer: B
Rationale: Competitive antagonists shift potency (EC50), while noncompetitive reduce efficacy (Emax), a key pharmacological distinction.
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Inhaled corticosteroids in Bronchial Asthma:
- A. Produce modest immediate bronchodilation
- B. Are synergistic with inhaled methacholine
- C. Are antagonized by atropine
- D. Inhibit IgE-antigen binding
Correct Answer: D
Rationale: Inhaled corticosteroids reduce inflammation by inhibiting IgE-mediated responses.
The nurse is teaching a patient about rifampin. Which statement by the patient indicates understanding of the teaching?
- A. I should not wear soft contact lenses while taking rifampin
- B. I will need regular eye examinations while taking this drug
- C. I will report orange urine to my provider immediately
- D. I understand that renal toxicity is a common adverse effect
Correct Answer: A
Rationale: Rifampin stains fluids red-orange, risking soft lens damage; eye exams are for ethambutol, and urine color is benign. Patients taking rifampin should be warned that urine, feces, saliva, sputum, sweat, and tears may turn a harmless red-orange color.
Glucocorticoids causes:
- A. Protein catabolism and muscle atrophy
- B. Protein anabolism and increase of muscle mass
- C. Stimulation of growth in children
- D. Decrease of \mathrm{Na}+ reabsorbtion and \mathrm{K}+\mathrm{K}+ excretion
Correct Answer: A
Rationale: Glucocorticoids cause protein catabolism and muscle atrophy by breaking down proteins.
Varicella vaccine is recommended to be given to patients who are:
- A. HIV positive with a CD4+ T-lymphocyte percentage less than 15%
- B. Taking corticosteroids (up to 2 mg/kg/day or less than 20 mg/day)
- C. Pregnant
- D. Immunocompromised
Correct Answer: B
Rationale: Varicella vaccine is safe with low-dose steroids; HIV with low CD4 , pregnancy , or immunocompromise contraindicate it.
In choosing a benzodiazepam to treat anxiety the prescriber needs to be aware of the possibility of dependence. The benzodiazepam with the greatest likelihood of rapidly developing dependence is:
- A. Chlordiazepoxide (Librium)
- B. Clonazepam (Klonopin)
- C. Alprazolam (Xanax)
- D. Oxazepam (Serax)
Correct Answer: C
Rationale: Alprazolam's short half-life increases dependence risk.