Name the following Arterial Blood Gas (ABG) values: pH 7.31, PaCO2 44, HCO3- 12

Choice A reason: Affinity is not about dosage form but the strength of drug-receptor binding. Dosage is unrelated to receptor interaction, so this is incorrect for affinity’s definition.

Choice B reason: Low affinity means weak attraction to receptors, not strong. High affinity indicates strong binding, so this statement is incorrect.

Choice C reason: High affinity means strong attraction between drug and receptor, enhancing binding and effect. This is accurate, making it a correct choice.

Choice D reason: Affinity influences potency; higher affinity often means greater potency at lower doses. This relationship is correct, making it a correct choice.

Choice E reason: Affinity is the strength of attraction between drug and receptor, a fundamental pharmacological concept. This definition is accurate, so this is a correct choice.

Choice A reason: Adrenergic neuron blockers, like guanethidine, reduce blood pressure by inhibiting norepinephrine release. They are not first-line for stage 1 hypertension (140-159/90-99 mm Hg). Their side effects, like orthostatic hypotension, make them less suitable. Lifestyle changes are preferred initially for this patient’s mild elevation and normal diagnostic tests, making this choice inappropriate.

Choice B reason: Beta blockers, like atenolol, reduce heart rate and cardiac output, lowering blood pressure. They are not first-line for stage 1 hypertension without compelling indications (e.g., heart failure). Guidelines recommend lifestyle modifications first for this patient’s blood pressure range, as they effectively reduce risk without medication side effects, making this choice less suitable.

Choice C reason: For stage 1 hypertension (140-159/90-99 mm Hg) with normal diagnostic tests, guidelines recommend lifestyle changes, such as diet, exercise, and weight loss, as first-line treatment. These reduce blood pressure by improving vascular health and reducing cardiac strain, offering a low-risk approach to manage mild hypertension effectively, making this the correct choice.

Choice D reason: ACE inhibitors, like lisinopril, block angiotensin II formation, reducing blood pressure. They are effective but not first-line for stage 1 hypertension without comorbidities. Lifestyle changes are prioritized to avoid medication side effects like cough or hyperkalemia, making this choice less appropriate for initial management in this patient.