Which of the following molecular actions most likely mediated the analgesic effect of morphine in the patient with multiple fractures?

Correct Answer: D

Rationale: The opening of K+ channels on postsynaptic neurons is a key molecular action that mediates the analgesic effect of opioids like morphine. This action leads to hyperpolarization of the neuron, reducing its excitability and inhibiting pain transmission. Therefore, in a patient with severe pain due to multiple fractures, the opening of K+ channels by morphine would be the most likely mechanism responsible for the analgesic effect.

Correct Answer: A

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

Correct Answer: D

Rationale: Meperidine is a commonly used opioid analgesic that is often used in detoxification programs due to its ability to help manage withdrawal symptoms. In this case, the patient was undergoing a detoxification program supervised by surgery, and a drug was administered intravenously. Meperidine is a likely choice as it can help alleviate withdrawal symptoms and manage pain during the detoxification process.

Correct Answer: B

Rationale: The symptoms described in the scenario, such as elevated mood, rapid speech, muscle twitching, and dilated pupils, are consistent with the effects of marijuana use. Increased heart rate is a common physiological response to smoking marijuana due to the drug's impact on the cardiovascular system. Additionally, euphoria and uncontrollable laughter are typical psychological effects of marijuana use, further supporting the choice of increased heart rate as the correct answer.

Correct Answer: D

Rationale: The patient's signs and symptoms, such as mydriasis, tonic-clonic seizure, shallow respiration, and cardiovascular collapse leading to death, are consistent with LSD intoxication. LSD is known to cause agitation, altered mental status, and severe physiological effects, making it the most likely cause of the patient's death.