Morphine causes the following effects EXCEPT:

Correct Answer: B

Rationale: The correct answer is B: Dilatation of the biliary duct. Morphine does not cause dilation of the biliary duct; instead, it can lead to biliary spasm and constriction. Morphine commonly causes constipation by decreasing gut motility, urinary retention by affecting the bladder sphincter, and bronchiolar constriction by acting on the respiratory system. These effects are well-documented pharmacological actions of morphine.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Monoamine Oxidase A (MAO-A) is an enzyme responsible for metabolizing neurotransmitters such as norepinephrine, serotonin, and tyramine. 2. MAO-A specifically targets norepinephrine and serotonin, making choice A correct. 3. Choices B, C, and D are incorrect as they incorrectly describe the functions and selectivity of MAO-A. In summary, MAO-A is responsible for norepinephrine, serotonin, and tyramine metabolism, making choice A the correct answer.

Correct Answer: C

Rationale: The correct answer is C because cordiamine does not decrease aortic and coronary flow; instead, it actually increases coronary flow. Cordiamine stimulates the CNS, facilitates movement coordination, acts as a respiratory analeptic, and counteracts central depression from other drugs. Choice A is incorrect as cordiamine does stimulate the CNS and facilitates movement coordination. Choice B is incorrect as cordiamine is indeed a respiratory analeptic of mixed action. Choice D is incorrect as cordiamine does counteract central depression from other drugs like barbiturates.

Correct Answer: C

Rationale: The correct answer is C because sharp swings from a cheerful mood to an aggressive state are not typically associated with barbiturate intoxication. Barbiturates generally depress the central nervous system, leading to symptoms such as stupor, confusion, and slowed thinking. Choice A includes symptoms like vertigo and myasthenia, which can be experienced during barbiturate intoxication. Choice B includes symptoms like perceptual distortions, behavior changes, and speech excitation, which are commonly seen in barbiturate intoxication. Choice D mentions sleep with subsequent weakness and headaches, which are also common symptoms of barbiturate intoxication. Overall, the incorrect choices describe symptoms that align with barbiturate intoxication, making C the outlier.

Correct Answer: B

Rationale: The correct answer is B: Aethylmorphine hydrochloride. Antitussives of narcotic type act on the cough center in the brain to suppress cough reflex. Aethylmorphine is an opioid derivative that exerts its antitussive effect centrally. Glaucine hydrochloride (A) is a non-narcotic antitussive derived from plants. Tusuprex (C) is a non-narcotic antitussive that acts peripherally. Libexine (D) is an antihistamine, not an antitussive.