Two nurses are discussing the theories of drug-receptor interaction. Which statements are true regarding the affinity of a drug and for its receptor? (Select all that apply)

Choice A reason: ACE inhibitors cause dry cough by inhibiting bradykinin breakdown, which accumulates and irritates the airways. ARBs block angiotensin II receptors without affecting bradykinin, eliminating this side effect. This makes ARBs a suitable alternative for patients experiencing cough, confirming this as the correct choice.

Choice B reason: Hyperkalemia occurs with both ACE inhibitors and ARBs due to reduced aldosterone production, which decreases potassium excretion. Both drug classes affect the renin-angiotensin-aldosterone system similarly, so switching to an ARB does not eliminate this risk, making this choice incorrect for the question.

Choice C reason: Hypotension is a shared side effect of ACE inhibitors and ARBs, as both reduce blood pressure by inhibiting the renin-angiotensin system. ARBs block angiotensin II receptors, causing vasodilation similar to ACE inhibitors, so this side effect persists, making this choice incorrect.

Choice D reason: Angioedema, though rare, can occur with both ACE inhibitors and ARBs. While less common with ARBs, it’s not eliminated, as it may result from mechanisms beyond bradykinin accumulation. Switching to an ARB doesn’t guarantee avoidance of angioedema, making this choice incorrect.

Choice A reason: Theophylline is rarely used due to toxicity risks and less efficacy compared to beta-agonists. Increasing fluticasone dose doesn’t address acute exacerbations, as inhaled corticosteroids act slowly. Oxygen is appropriate, but this regimen lacks rapid-acting bronchodilators, making it inadequate for acute asthma management.

Choice B reason: Four puffs of albuterol via inhaler may be insufficient for severe asthma (90% saturation, wheezes). Theophylline is outdated, and nebulized treatments are more effective in emergencies. Oxygen is needed, but this combination lacks systemic steroids for inflammation, making it less optimal.

Choice C reason: Intravenous glucocorticoids reduce airway inflammation rapidly, nebulized albuterol and ipratropium provide synergistic bronchodilation, and oxygen corrects hypoxia (90% saturation). This aligns with guidelines for acute asthma exacerbations, addressing inflammation, bronchoconstriction, and oxygenation, making it the correct and comprehensive treatment choice.

Choice D reason: Intramuscular glucocorticoids are slower than intravenous for acute asthma. Salmeterol, a long-acting beta-agonist, is inappropriate for acute exacerbations, as it lacks rapid onset. Oxygen is needed, but this regimen doesn’t address immediate bronchoconstriction effectively, making it incorrect for emergency management.