Which substance can increase central nervous system depression if taken with diphenhydramine?

A. Constipation: Bile acid sequestrants bind bile acids in the intestine, which can slow gastrointestinal motility and increase stool firmness. Constipation is one of the most common adverse effects, particularly in older adults or clients with low fluid intake.

B. Bleeding: These medications do not affect platelet function or coagulation pathways. Bleeding is more commonly associated with anticoagulants or antiplatelet agents rather than lipid-lowering bile acid sequestrants.

C. Hyperglycemia: Bile acid sequestrants do not directly alter glucose metabolism or insulin activity. Elevated blood glucose levels are typically related to endocrine disorders or medications such as corticosteroids.

D. Urinary retention: Bile acid sequestrants act within the gastrointestinal tract and have minimal systemic absorption. Urinary retention is more often linked to anticholinergic medications rather than lipid-lowering agents.

A. Salivation: Diphenhydramine, an antihistamine with anticholinergic properties, typically reduces salivation rather than increases it. Excessive drooling is not a side effect of this medication.

B. Watery eyes: Diphenhydramine works to relieve allergic symptoms, including watery eyes, so this symptom is more likely to be a reason for taking the medication rather than a side effect.

C. Urinary frequency: Anticholinergic effects of diphenhydramine usually cause urinary retention, not increased frequency. Clients may experience difficulty voiding rather than needing to urinate more often.

D. Constipation: The anticholinergic action of diphenhydramine can slow gastrointestinal motility, leading to constipation. Clients should be advised about this potential side effect and strategies to prevent it, such as increased fluid and fiber intake.