A 72-year-old woman recently diagnosed with Alzheimer disease started pharmacotherapy with donepezil. Which of the following sets of adverse effects most likely occurred during the first days of treatment?

Correct Answer: B

Rationale: The common side effects of donepezil, a cholinesterase inhibitor used in Alzheimer's disease, include gastrointestinal disturbances such as nausea, vomiting, and diarrhea. These adverse effects are often experienced in the initial days of treatment as the body adjusts to the medication.

Correct Answer: A

Rationale: β\(_2\)-adrenergic receptors are G-protein-coupled receptors that have seven transmembrane domains, which is a characteristic feature of this receptor family.

Correct Answer: A

Rationale: Hydralazine causes vasodilation, which can lead to reflex tachycardia, headache, and postural hypotension.

Correct Answer: A

Rationale: The correct answer is A. Increased synthesis of adenylyl cyclase. One of the leading hypotheses about the molecular mechanism of action of lithium is its ability to increase the synthesis of adenylyl cyclase. Adenylyl cyclase is an enzyme involved in the production of cyclic adenosine monophosphate (cAMP), which plays a role in cellular signaling pathways. By increasing the synthesis of adenylyl cyclase, lithium may help to regulate intracellular signaling and neurotransmitter release, contributing to its mood-stabilizing effects in bipolar disorder.

Correct Answer: C

Rationale: Lithium reaches its peak serum levels typically within 2 to 4 hours after oral administration.