A Rare Case of Famotidine-Induced Delirium in a Peritoneal Dialysis Patient

Effects of anti-ulcer drugs on delirium in trauma patients

OBJECTIVE

Histamine-2 receptor antagonists (H2RAs) may induce a higher risk of developing delirium than proton pump inhibitors (PPIs), but current evidence is insufficient. Therefore, this study aimed to investigate whether anti-ulcer drugs increase delirium risk.

METHOD

Data were obtained from the medical records of patients admitted to a hospital due to trauma. We compared the incidence of delirium in patients who received H2RAs and PPIs with that in patients who received no anti-ulcer drugs.

RESULTS

A total of 150, 158, and 238 patients received H2RAs, PPIs, and no anti-ulcer drugs, respectively. Delirium incidence was significantly higher in patients who received H2RAs (34.0%) and PPIs (44.9%) than in those who did not receive anti-ulcer drugs (22.3%). Even after adjustment for possible confounding factors, the association between H2RAs and delirium remained (adjusted OR 1.78; 95% CI 1.04-3.05), but that between PPIs and delirium was attenuated (adjusted OR 1.25; 95% CI 0.71-2.23).

CONCLUSIONS

Our results show that H2RAs are associated with delirium risk. We replicated findings of a previous data-driven study. Clinicians need to consider the effect of delirium in anti-ulcer drug selection.

Delirium and its Pharmacological Causes in Older People, Part Two

Delirium is a syndrome that can arise from many causes or underlying conditions, and though it has been reported in younger patients, it is more prevalent in older people, though it can occur in other age groups as well. Identifying delirium is challenging in older people because of the coexistence of underlying dementia or depression, which may further complicate the presentation. Drug-induced delirium is one of the major causes of delirium, and evaluation of this potential cause or contribution is an important component of the evaluation process, since it can lead to poor patient outcomes. Part one of this three part series reviewed the epidemiology, pathophysiology, evaluation, diagnostic process, and causes of delirium in older people, with a focus on the pharmacological causes. Part two of this series continues to review drugs and drug classes that can cause or contribute to delirium in older people.

Delirium risk of histamine-2 receptor antagonists and proton pump inhibitors: A study based on the adverse drug event reporting database in Japan

OBJECTIVE

Although histamine-2 receptor antagonists (H2RAs) have been shown to be more likely to cause delirium than proton pump inhibitors (PPIs), these results were not adjusted for potential confounding factors. Accordingly, we investigated whether H2RAs and PPIs are risk factors for delirium, even when adjusting for other risk factors by analyzing adverse drug event reports compiled in the post-marketing stages of drugs provided by the Japanese regulatory authorities.

METHOD

We analyzed 577,431 reports in the Japanese Adverse Drug Event Report database from April 2004 to July 2020.

RESULTS

Of all reports analyzed, 2532 described delirium, and 574,899 described other adverse events. Delirium was associated with H2RAs (crude reporting odds ratio, ROR, 4.17; 95% CI, 3.34-5.22) but not PPIs (crude ROR 0.62; 95% CI 0.43-0.90). Even with adjustment for age, sex, history of dementia or depression, and concomitant drugs reported as risk factors for delirium, the use of H2RAs showed a significantly higher adjusted ROR than that of PPIs (H2RAs: adjusted ROR 3.99; 95% CI 3.18-5.01 and PPIs: adjusted ROR 0.58; 95%CI 0.40-0.84).

CONCLUSIONS

These results suggest that, from a cognitive perspective, PPIs may be preferable to H2RAs for patients with or at risk for delirium.

Reduction in the rate of postoperative delirium by switching from famotidine to omeprazole in Japanese hepatectomized recipients

Background

Hepatectomy is a highly invasive procedure with a high probability of postoperative delirium. Treatment with antiulcer drugs is indispensable after hepatectomy for anastomotic ulcer management. The clinical pathway for hepatectomy was reviewed and the antiulcer drug used was switched from famotidine, a H₂-receptor antagonist, to omeprazole, a proton pump inhibitor, owing to the pharmacist’s intervention.

Methods

Hepatectomized recipients over 65 years of age, except in the cases of laparoscopic surgery and intensive care unit entry, were treated with famotidine injections (10 patients) or omeprazole injections (11 patients), and the incidence rates and severity of delirium were compared between the famotidine and omeprazole groups. The delirium after hepatectomy was assessed using the Japanese version of the NEECHAM confusion scale.

Results

The incidence rates of delirium were 90% in the famotidine group and 27.3% in the omeprazole group. Four out of 9 recipients in the famotidine group were injected with haloperidol to treat for delirium, but no recipients needed this treatment in the omeprazole group.

Conclusions

Compared with famotidine, the use of omeprazole was found to be effective in reducing the incidence rate and severity of postoperative delirium in patients undergoing hepatectomy. Pharmacists should actively strive to mitigate the risks of delirium.