Atropine is frequently used prior to administration of inhalant anesthetics to reduce:

Correct Answer: B

Rationale: The correct answer is B: Secretions. Atropine is used to reduce respiratory secretions before inhaling anesthetics as it helps prevent airway obstruction and aspiration. It does not affect muscle tone or nausea/vomiting. Choice A is incorrect because atropine can actually increase muscle tone. Choice C is incorrect because atropine does not directly address nausea and vomiting. Overall, the main purpose of using atropine in this context is to decrease secretions, making option B the correct answer.

Correct Answer: D

Rationale: The correct answer is D: Epinephrine. 1. Epinephrine is the drug of choice in anaphylactic shock due to its alpha and beta-adrenergic effects, which help reverse vasodilation, bronchoconstriction, and increased vascular permeability. 2. Methoxamine (A) acts as a selective alpha-1 adrenergic agonist and may worsen the vasodilation in anaphylactic shock. 3. Terbutaline (B) is a beta-2 adrenergic agonist used in asthma but may not be as effective in reversing the systemic effects of anaphylactic shock. 4. Norepinephrine (C) is a potent vasoconstrictor but lacks the beta-adrenergic effects needed to reverse bronchoconstriction and vascular permeability in anaphylactic shock.

Correct Answer: D

Rationale: The correct answer is D: Hyperglycemia. Beta-blockers can cause bronchoconstriction (Choice A) by blocking beta-2 receptors, leading to airway constriction. They depress myocardial contractility and excitability (Choice B) by blocking beta-1 receptors in the heart. "Supersensitivity" of beta-receptors (Choice C) can occur upon rapid withdrawal of beta-blockers due to upregulation of receptors. However, beta-blockers typically do not cause hyperglycemia (Choice D) as they may actually mask the symptoms of hypoglycemia.

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: Selegiline. Selegiline is a monoamine oxidase inhibitor used in the treatment of Parkinsonian disorders by increasing dopamine levels in the brain. Phenytoin (A) is an anticonvulsant, not used for Parkinson's. Haloperidol (C) is an antipsychotic, may worsen Parkinson's symptoms. Fluoxetine (D) is an antidepressant, not specific for Parkinson's treatment. Therefore, Selegiline is the most appropriate choice due to its mechanism of action in increasing dopamine levels to alleviate Parkinsonian symptoms.