Beta-adrenoceptor antagonists:

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: The correct answer is B (1.7 mEq/L). Blurred vision, tinnitus, and severe diarrhea are symptoms of lithium toxicity. A level of 1.7 mEq/L falls within the toxic range (1.5-2.5 mEq/L). This level indicates an increased risk of toxicity symptoms. Choices A, C, and D are outside the toxic range and would not typically present with these severe symptoms. Option A is slightly elevated but not typically associated with severe symptoms. Option C is above normal but not yet toxic. Option D is significantly high and would likely present with more severe symptoms than just blurred vision, tinnitus, and diarrhea.

Correct Answer: B

Rationale: The correct answer is B: lamotrigine (Lamictal). Step-by-step rationale: 1. Divalproex, carbamazepine, and gabapentin are all anticonvulsant medications commonly used to treat seizures and mood disorders. 2. Lamotrigine also belongs to this group as it is an anticonvulsant used for epilepsy and bipolar disorder. 3. Clonazepam is a benzodiazepine used for anxiety and seizures, not in the same class as the other drugs. 4. Risperidone and aripiprazole are antipsychotic medications used for schizophrenia and bipolar disorder, not in the same class as the other drugs.

Correct Answer: B

Rationale: The correct answer is B: Hypokalemia. Hydrochlorothiazide is a diuretic that can lead to potassium loss, increasing the risk of hypokalemia. Digoxin toxicity is more likely to occur in the presence of hypokalemia. Hypocalcemia (A) is not directly related to these medications. Hyperkalemia (C) and hypermagnesemia (D) are unlikely with hydrochlorothiazide and digoxin use.