Characteristics of salmeterol include all of the following EXCEPT:

Correct Answer: C

Rationale: The correct answer is C because salmeterol does not stimulate heart rate, contractility, or cardiac output. Salmeterol is a long-acting beta2 agonist that primarily acts on the bronchial smooth muscles to provide bronchodilation in conditions like asthma and chronic obstructive pulmonary disease. Choice A is incorrect because salmeterol is indeed a potent selective beta2 agonist. Choice B is also incorrect as salmeterol does not cause uterine relaxation. Choice D is incorrect as salmeterol is commonly used in the therapy of asthma to provide long-term symptom control.

Correct Answer: A

Rationale: The correct answer is A: Triazolam. Triazolam has a short half-life, leading to quicker elimination from the body, which can cause a more pronounced "rebound" effect after discontinuation, resulting in rebound insomnia. Flurazepam and Temazepam have longer half-lives, so they are less likely to cause rebound insomnia. Choice D is incorrect as not all benzodiazepines cause rebound insomnia equally.

Correct Answer: B

Rationale: The correct answer is B: Carbamazepine. Carbamazepine is most commonly associated with the development of Steven-Johnson syndrome due to its high risk of causing severe hypersensitivity reactions. This drug has been widely reported to be a major cause of Steven-Johnson syndrome compared to the other options. Phenytoin (choice A) is known for causing different types of skin reactions but is less commonly linked to Steven-Johnson syndrome. Valproate (choice C) and Lamotrigine (choice D) have also been associated with skin reactions, but the incidence of Steven-Johnson syndrome with these drugs is lower compared to Carbamazepine.

Correct Answer: B

Rationale: The correct answer is B: Morphine. Morphine is a phenanthrene derivative as it belongs to the opioid class of analgesics derived from the phenanthrene nucleus. Fentanyl (A) is a synthetic opioid, not derived from phenanthrene. Methadone (C) is a synthetic opioid unrelated to phenanthrene. Pentazocine (D) is a mixed opioid agonist-antagonist, not a phenanthrene derivative. Therefore, based on the chemical structure and classification, morphine is the only phenanthrene derivative among the options.

Correct Answer: C

Rationale: The correct answer is C: Aspirin. Salicylic acid is the parent compound of aspirin. Aspirin is a salicylic acid derivative commonly used for its anti-inflammatory and analgesic properties. Phenylbutazone (A) is a pyrazolone derivative, Ketamine (B) is a dissociative anesthetic, and Tramadol (D) is a synthetic opioid. Aspirin's chemical structure contains the salicylic acid moiety, making it the only salicylic acid derivative among the options provided.