1Increase the cimetidine dose because confusion indicates that gastric acid suppression is inadequate.
2Administer diphenhydramine at bedtime and continue cimetidine to improve sleep during hospitalization.
3Notify the prescriber and review cimetidine as a cause of the acute confusion before the next dose is given.✓ Correct answer
4Document age-related cognitive decline and delay medication review until the next routine appointment.
Explanation
Cimetidine can cause reversible mental confusion, agitation, hallucinations, and disorientation, with increased concern in older or severely ill clients. The close temporal relationship requires prompt medication review and evaluation for other delirium causes before another dose. Increasing the dose or adding diphenhydramine can worsen cognitive effects, and acute confusion should not be dismissed as normal aging.
Clinical reasoning Abrupt inattention or disorientation after a medication change is delirium until evaluated. Cimetidine-associated confusional states can begin within days and resolve after withdrawal.
Decision rule For new confusion after cimetidine initiation, protect safety, assess reversible causes, and obtain prescriber review before continued exposure.
Scenario An older adult began cimetidine for dyspepsia several days ago. The family now reports new confusion and disorientation; cognition was intact before treatment.
Cimetidine-associated confusion — A reversible central nervous system adverse effect that can include disorientation, agitation, hallucinations, or mental confusion.
Medication-induced delirium — An acute change in attention and cognition caused or worsened by a medication.
Beers Criteria H2 — Cimetidine flagged for cognitive risk in older adults; famotidine preferred.