A patient is using albuterol inhaler before exercise. What is the most likely reason for this use?

Correct Answer: A

Rationale: The correct answer is A: Prevention of bronchospasm. Albuterol is a bronchodilator commonly used to relieve bronchospasm in conditions like asthma. Before exercise, albuterol can help prevent exercise-induced bronchospasm by opening up the airways and making breathing easier. Choice B, pain management, is incorrect as albuterol is not used for pain relief. Choice C, reduction of blood pressure, is incorrect as albuterol primarily targets the lungs, not the cardiovascular system. Choice D, treatment of COPD, is incorrect as while albuterol can be used in COPD management, using it specifically before exercise is more indicative of preventing bronchospasm in asthma.

Correct Answer: A

Rationale: Rationale: Diphenhydramine is a first-generation antihistamine that works by blocking histamine receptors in the respiratory tract. Histamine is released during an allergic reaction and causes symptoms like a runny nose. By blocking histamine receptors, diphenhydramine effectively reduces these symptoms. Therefore, option A is correct. Option B is incorrect because diphenhydramine does not stimulate beta-2 receptors. Option C is incorrect as diphenhydramine does not increase mucus production. Option D is incorrect as diphenhydramine does not block acetylcholine receptors in the brain.

Correct Answer: B

Rationale: The correct answer is B: Dilating the bronchioles. Albuterol is a beta-2 adrenergic agonist that acts on bronchial smooth muscle to cause bronchodilation, improving airflow in patients with COPD. This effect helps relieve symptoms of bronchoconstriction and shortness of breath. Choices A, C, and D are incorrect because albuterol does not increase mucus production, decrease bronchial inflammation, or inhibit histamine release. It primarily targets bronchial smooth muscle to promote bronchodilation.

Correct Answer: B

Rationale: The therapeutic index value of 2 indicates that the toxic dose is 2 times the effective dose. To have a 50% chance of developing toxic side effects, the patient would need to take a dose that is half of the toxic dose. This means the patient would need to take 1/2 of the toxic dose at each administration. Since the therapeutic index is 2, the patient would need to divide the toxic dose into 2 equal parts, which results in 2 doses. Therefore, the correct answer is B: Two doses. Summary: A: Incorrect - Taking one dose would exceed the therapeutic index and increase the risk of toxic side effects. C: Incorrect - Not providing a clear answer. D: Incorrect - Incomplete option.

Correct Answer: A

Rationale: The correct answer is A: Cyproheptadine. Cyproheptadine is a histamine and serotonin receptor antagonist, making it suitable for treating intestinal hypermobility of carcinoid tumors. Histamine and serotonin play a role in intestinal motility, and blocking their receptors can help alleviate symptoms. Summary of other choices: B: Ergonovine is a uterine stimulant and is not indicated for treating intestinal hypermobility. C: Loratadine is a selective histamine H1 receptor antagonist used for allergies, not for intestinal hypermobility. D: Promethazine is an antihistamine and antiemetic, but it is not commonly used for treating intestinal hypermobility associated with carcinoid tumors.