Which of the following was most likely the half-life of the drug (in hours)?

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: D

Rationale: The law of mass action governs the relationship between the concentration of a drug and the association and dissociation of the drug-receptor complex. According to this law, the rate of a chemical reaction is directly proportional to the product of the concentrations of the reacting substances. In the context of pharmacology, this means that the concentration of a drug influences its interaction with receptors, affecting the pharmacological response.

Correct Answer: D

Rationale: The coma caused by thio- pental is most likely due to a pseudoallergic reaction, as this type of reaction can lead to severe symptoms such as seizures and coma. Pseudoallergic reactions are non-immunologic reactions that can occur in individuals even without prior exposure to the drug, making them unpredictable and potentially life-threatening. In this case, the patient's history of acute intermittent porphyria may have contributed to the pseudoallergic reaction to thio- pental.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Lipid solubility of a drug is influenced by its pKa value. Since valproic acid has a pKa of 5, it would likely be lipid soluble at a pH of 7 in the duodenal lumen. The Henderson-Hasselbalch equation suggests that when the pH is higher than the pKa, the drug will predominantly be in its non-ionized, lipid-soluble form. In this case, the drug would be about 24% lipid soluble in the duodenal lumen, making choice B the correct answer.