A patient has allergies and takes an antihistamine. The patient wants to know how the drug works. The nurse understands that antihistamines work because they are what?

Choice A reason: Dry cough is a common, not serious, side effect of ACE inhibitors due to bradykinin accumulation. While bothersome, it’s not life-threatening like angioedema. It often necessitates switching to an ARB, but calling it serious overstates the risk, making this choice incorrect.

Choice B reason: Dry cough occurs in 5-20% of ACE inhibitor users but doesn’t typically subside with continued use, as bradykinin accumulation persists. Patients often require a medication change (e.g., to ARBs), making the claim that it will subside over time inaccurate and incorrect.

Choice C reason: Dry cough is common but not universal in ACE inhibitor users, affecting 5-20% of patients due to variable bradykinin sensitivity. Stating it occurs in all patients is inaccurate, as many tolerate ACE inhibitors without cough, making this choice incorrect.

Choice D reason: Dry cough, caused by bradykinin buildup, affects some ACE inhibitor users and is uncomfortable, often requiring a switch to an ARB, which doesn’t affect bradykinin. This accurately reflects the side effect’s impact and management, making it the correct choice for the nurse’s response.

Choice A reason: Metabolic acidosis has low pH and HCO3-. Normal pH (7.41) and high HCO3- (30) suggest alkalosis, not acidosis, so this is incorrect for the ABG values.

Choice B reason: Respiratory acidosis has high PaCO2 and low pH. Normal pH and high HCO3- indicate metabolic alkalosis, not respiratory acidosis, so this is incorrect.

Choice C reason: Respiratory alkalosis has low PaCO2 and high pH. High PaCO2 (46) and HCO3- rule this out, pointing to metabolic alkalosis, so this is incorrect.

Choice D reason: Normal pH (7.41), high PaCO2 (46), and high HCO3- (30) indicate metabolic alkalosis fully compensated by respiratory CO2 retention. This is correct.