A patient with asthma is prescribed salbutamol. Salbutamol works by:

Correct Answer: B

Rationale: The correct answer is B because salbutamol is a beta-2 adrenergic receptor agonist, which leads to bronchodilation by relaxing bronchial smooth muscle. This mechanism helps to relieve bronchoconstriction in asthma. Option A is incorrect as leukotriene receptors are not targeted by salbutamol. Option C is incorrect because salbutamol does not inhibit histamine release. Option D is incorrect as salbutamol does not increase mucus production; in fact, it may help reduce mucus secretion by improving airflow.

Correct Answer: A

Rationale: The correct answer is A: Methotrexate. Methotrexate is a disease-modifying antirheumatic drug (DMARD) that suppresses the immune system to reduce inflammation in rheumatoid arthritis. It helps to slow down the progression of the disease and prevent joint damage. Prednisone (B) is a corticosteroid that helps reduce inflammation but does not suppress the immune system in the same way as Methotrexate. Aspirin (C) is a nonsteroidal anti-inflammatory drug (NSAID) that helps with pain and inflammation but does not alter the immune response. Hydroxychloroquine (D) is an antimalarial drug that can be used to treat rheumatoid arthritis but does not primarily suppress the immune system like Methotrexate.

Correct Answer: B

Rationale: The correct answer is B: Improving insulin sensitivity in peripheral tissues. Metformin enhances the response of peripheral tissues to insulin, allowing for better utilization of glucose, reducing blood sugar levels. This mechanism helps to decrease insulin resistance, a key feature in type 2 diabetes. Other choices are incorrect because metformin does not directly increase insulin secretion from the pancreas (choice A), inhibit glucose absorption in the intestine (choice C), or increase the excretion of glucose in the urine (choice D). These mechanisms do not align with how metformin primarily works to improve glucose control in type 2 diabetes.

Correct Answer: A

Rationale: The correct answer is A: Epinephrine. Epinephrine is the drug of choice for treating anaphylaxis due to its rapid action in constricting blood vessels, relaxing smooth muscles, and opening airways. It helps counteract the severe allergic reaction and can save a person's life. Diphenhydramine (B) is an antihistamine that can help relieve itching and hives but is not as effective or fast-acting as epinephrine in treating anaphylaxis. Loratadine (C) is also an antihistamine, which is used for allergies but not for immediate treatment of anaphylaxis. Ibuprofen (D) is a nonsteroidal anti-inflammatory drug (NSAID) used for pain relief and inflammation, but it does not have the life-saving properties needed to treat anaphylaxis.

Correct Answer: A

Rationale: The correct answer is A: Cough and throat irritation. Albuterol is a bronchodilator commonly used to treat asthma and COPD. The mechanism of action of albuterol can lead to irritation of the throat and trigger coughing as a common adverse effect. This is due to the stimulation of beta-2 adrenergic receptors in the airways, causing relaxation of the smooth muscles but also potentially irritating the throat lining. Choices B, C, and D are incorrect because constipation, hypertension, and increased urination are not typically associated with albuterol inhalation therapy.