Correct Answer: A

Rationale:
Choice A is correct because hypoalbuminemia lowers albumin levels, which bind drugs in plasma; this alters distribution to tissues, potentially increasing free drug concentrations and affecting efficacy or toxicity.
Choice B is incorrect as solubility relates to absorption, not albumin binding.
Choice C is wrong because less albumin means more free drug, not less, due to reduced binding.
Choice D is incorrect since albumin-bound drugs are less readily excreted; lower binding prolongs drug presence in circulation.

Correct Answer: C

Rationale:
Choice C is correct because receptor agonists, which activate receptors, can lead to desensitization or downregulation with continuous use as the body reduces receptor sensitivity or number to compensate.
Choice A is incorrect as irreversible binding is rare and not typical for agonists.
Choice B is wrong because upregulation occurs with antagonists, not agonists.
Choice D is incorrect since agonists typically show a direct, not inverse, concentration-action relationship.

Correct Answer: D

Rationale:
Choice D is correct because unbinding a drug from plasma proteins increases its free fraction, allowing more to be filtered and excreted by the kidneys, enhancing renal clearance.
Choice A is incorrect as reduced kidney perfusion decreases excretion.
Choice B is wrong because chronic renal disease impairs excretion, not increases it.
Choice C is incorrect since competition for transport sites would reduce, not enhance, excretion.

Correct Answer: B

Rationale:
Choice B is correct because crushing a sustained-release capsule releases all drug at once, bypassing controlled release, which can lead to toxic levels quickly.
Choice A is incorrect as disintegration isn't harmful itself, just alters release.
Choice C is wrong because malabsorption isn't the primary risk—overdose is.
Choice D is incorrect since deterioration implies drug degradation, not the immediate danger of crushing.

Correct Answer: C

Rationale:
Choice C is correct because women generally have a higher percentage of body fat, affecting the volume of distribution for lipophilic drugs, a key pharmacokinetic difference.
Choice A is incorrect as body temperature differences are minimal and don't significantly alter pharmacokinetics.
Choice B is wrong because men, not women, typically have greater muscle mass.
Choice D is incorrect since subjective factors aren't proven pharmacokinetic variables.