Indicate an antiseizure drug, inhibiting central effects of excitatory amino acids:

Correct Answer: D

Rationale: Step-by-step rationale: 1. Tiagabine inhibits the reuptake of GABA, an inhibitory neurotransmitter, reducing excitatory effects of amino acids. 2. This mechanism helps prevent seizures by increasing GABA levels in the brain. 3. Ethosuximide is used for absence seizures, not related to amino acids. 4. Lamotrigine blocks voltage-gated sodium channels. 5. Diazepam enhances the effects of GABA but does not directly inhibit excitatory amino acids.

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: The correct answer is A: Carbamazepine. Carbamazepine has a dual mechanism of action, functioning as both an antiseizure medication and an analgesic. It is commonly used to treat neuropathic pain and trigeminal neuralgia. Carbamazepine's analgesic properties stem from its ability to block voltage-gated sodium channels, reducing neuronal excitability and pain transmission. Summary of other choices: B: Ethosuximide - Primarily used for absence seizures, lacks analgesic properties. C: Phenytoin - Effective against various seizure types but does not have significant analgesic effects. D: Clonazepam - A benzodiazepine used as an antiseizure medication, but does not possess analgesic properties.

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.