The Hospice Clinician Blog

Hospice patients are, by definition, at high risk of delirium due to advanged age and terminal illness. Patients with dementia or cognitive impairment or who have a history of delirium are at even higher risk. In these patients, Histamine-2 Receptor Antagonists (H2RAs) such as ranitidine (Zantac), famotidine (Pepcid) and cimetidine (Tagamet) may cause delirium or other mental status changes, or may worsen cognitive impairment. Cimetidine, in particular, has been on the Beers List for years due, in part, to its potential for causing adverse CNS effects in the elderly. As of the 2012 update, the Beers List now contains the entire class of H2RAs. (See our Updated Beers List Blog Series)

How do H2RAs cause delirium?

It is well understood that drugs with anticholinergic activity can cause delirium and cognitive decline in elderly patients, especially those with Alzheimer’s disease or dementia. The H2RAs have varying degrees of anticholinergic activity (ranitidine and cimetidine – medium to high;  famotidine and nizatidine – low). There is inconsistent evidence linking H2RAs to delirium in clinical trials, but numerous case reports (particularly with cimetidine) indicate a possible relationship. When a patient suffers from delirium or an acute decline in cognitive status, always review their medication list. The obvious culprits, such as benzodiazepines and first-generation antihistamines, will stand out, but don’t overlook H2RAs as possible contributors.

Should H2RAs be avoided in hospice patients?

Sometimes. For patients at especially high risk of delirium, including those with cognitive impairment, consider another agent for acid suppression, such as an antacid or proton-pump inhibitor (PPI). For best cost-effectiveness, we recommend Prilosec OTC as the PPI of choice. When using an H2RA, keep the patient’s renal function in mind. All H2RAs are eliminated by the kidneys and have to be dose-adjusted for renal impairment; failure to do so will increase the risk of all side effects, including delirium. As a rule of thumb, cut the dose in half if the patient’s creatinine clearance is less than 50 mL/min, and consider further reductions in either dose or dosing frequency as renal function declines further.

Please post your comments/questions below. Outcome Resources strives to provide the very best hospice medication information to ensure not only cost efficiencies but best patient care. Contact Us to learn more about the resources available to help your hospice succeed.