Evaluation of the Direct Costs of Managing Adverse Drug Events in all Ages and of Avoidable Adverse Drug Events in Older Adults in Japan.

In Japan, medical costs are increasing annually, and the increase in national medical costs, particularly in the direct cost of managing adverse drug events, is high. An in-depth understanding of these costs is important for their reduction. This study aimed to calculate the direct cost of managing adverse drug events in all ages, including older adults, and that of avoidable adverse drug events in older adults. We conducted a retrospective survey on patients aged 1 year or older who visited Gifu Municipal Hospital in Japan. We investigated and calculated the direct cost of managing adverse drug events and that of avoidable adverse drug events based on the Beers Criteria Japanese version (BCJ) and "Guidelines for medical treatment and its safety in the elderly 2015" (GMTSE-2015) in inpatients and outpatients. Among 6,504 patients, 11.1% visited the hospital or were hospitalized due to adverse drug events. The direct costs per patient with adverse drug events were 21,281 and 22,590 yen (166 and 176 euros as on September 13, 2021) for outpatients, and 853,175 and 874,582 yen (6,648 and 6,815 euros) for inpatients of all ages and older adults, respectively. The direct costs of avoidable adverse drug events per patient using drugs listed in the BCJ and GMTSE-2015 for older adults were 3,212 and 3,341 yen (25 and 26 euros) for outpatients, and 55,548 and 80,246 yen (433 and 625 euros) for inpatients, respectively. In sum, considering both inpatients and outpatients in the whole country, the direct costs of managing adverse drug events were 804.53 billion and 597.19 billion yen (6,269 million and 4,653 million euros) per year for all ages and older ages, respectively. The direct cost of avoidable adverse drug events in older adults was 83.43-258.44 billion yen (650-2,013 million euros) per year. We found that, in Japan, high medical costs are often caused by managing adverse drug events, and that the costs of avoidable adverse drug events in older adults based on the BCJ and GMTSE-2015 account for a substantial proportion of the medical cost. Therefore, by using the BCJ and GMTSE-2015, avoiding adverse drug events and reducing medical costs may be possible.

Angioedema Caused by Drugs That Prevent the Degradation of Vasoactive Peptides: A Pharmacovigilance Database Study.

Angioedema results from the decreased degradation of vasoactive peptides such as substance P and bradykinin. In this study, we sought to clarify whether dipeptidyl peptidase-4 (DPP-4) and angiotensin-converting enzyme (ACE) inhibitors that suppress the degradation of substance P and bradykinin are involved in angioedema onset. We calculated information coefficients (ICs) by performing a disproportionality analysis to evaluate DPP-4/ACE inhibitor-induced angioedema using the Japanese Adverse Drug Event Report (JADER) database. No angioedema signals were detected for DPP-4 inhibitors; however, a signal was detected for ACE inhibitors (IC: 2.42, 95% confidence interval (CI): 2.19 to 2.65). Of the patients treated with DPP-4 inhibitors, four developed drug-induced angioedema in combination with ACE inhibitors, and all were taking vildagliptin. Signals were detected for enalapril (IC: 2.39, 95% CI: 2.06 to 2.71), imidapril (IC: 2.83, 95% CI: 2.38 to 3.27), lisinopril (IC: 2.28, 95% CI: 1.55 to 3.00), temocapril (IC: 1.35, 95% CI: 0.29 to 2.40), and trandolapril (IC: 1.57, 95% CI: 0.19 to 2.95). Both inhibitors inhibited the degradation of substance P and bradykinin and were thus expected to cause angioedema. However, no signal of angioedema was detected with the DPP-4 inhibitors, in contrast to some ACE inhibitors. This study found that ACE inhibitors and DPP-4 inhibitors, which inhibit the degradation of substance P and bradykinin, tended to have different effects on the onset of angioedema in clinical practice.

Effects of the number of drugs used on the prevalence of adverse drug reactions in children.

In pediatric individuals, polypharmacy would increase the prevalence of adverse drug reactions (ADRs). However, there is no report on the ADR increase adjusted for the influence of concomitant disease types. We conducted a retrospective study in pediatric patients to determine whether polypharmacy is a risk factor for ADR development, after the adjustment. Patients aged 1-14 years on medication who visited Gifu Municipal Hospital (Gifu, Japan) were included. We evaluated patient characteristics, ADR causality, ADR classification and severity, and ADR-causing drugs. We examined the association between ADR prevalence and number of drugs used. We performed multiple logistic regression analyses to investigate risk factors for ADR development. Of 1330 patients, 3.5% sought medical attention for ADRs. ADR causality was most often assessed as "possible," with gastrointestinal ADRs being the most common. Grade 1 ADRs were the most and antibiotics were the most common suspected ADR-inducing drug. The multiple logistic regression analysis showed that ≥ 2 or ≥ 4 drug use, neoplasms, mental and behavioral disorders, and circulatory system diseases significantly increased ADR prevalence. Polypharmacy increased the prevalence of ADR resulting in hospital visits in children, after adjusting for the influence of disease types. Therefore, proactive polypharmacy control measures are necessary for children.

Association between dipeptidyl peptidase-4 inhibitor and aspiration pneumonia: disproportionality analysis using the spontaneous reporting system in Japan.

PURPOSE: Dipeptidyl peptidase-4 inhibitor (DPP-4-Is), a kind of drug used for the treatment of diabetes, is considered to prevent the degradation of substance P that suppresses the occurrence of dysphagia. On the other hand, DPP-4 inhibitors are also known to act on the immune system. In this study, we used a spontaneous reporting system to evaluate the signals for dysphagia and aspiration pneumonia with DPP-4-Is. METHODS: We calculated reporting odds ratio (ROR) and information coefficients (IC) as disproportionality analysis to evaluate DPP-4-Is induced dysphagia and aspiration pneumonia using the Japanese Adverse Drug Event Report (JADER) database. RESULTS: For DPP-4-Is as a class, no signals were detected for dysphagia, but the signal for aspiration pneumonia was detected at ROR 1.67 (95% confidence interval [95% CI]: 1.20 to 2.34) and IC 0.70 (95% CI: 0.21 to 1.19). For aspiration pneumonia, trelagliptin was the only drug among the DPP-4-Is for which both ROR and IC signals were detected (ROR 9.99, 95% CI: 4.10 to 24.36; IC: 1.98, 95% CI: 0.78 to 3.18). ROR signals, but not IC signals, were detected for linagliptin (ROR 2.66, 95% CI: 1.19 to 5.94; IC: 1.09, 95% CI: - 0.004 to 2.19) and sitagliptin (ROR 1.84, 95% CI: 1.04 to 3.25; IC: 0.78, 95% CI: - 0.03 to 1.58). CONCLUSION: Since DPP-4 inhibitors prevent the degradation of substance P involved in swallowing reflex, DPP-4 inhibitors were expected to prevent dysphagia and aspiration pneumonia. However, this study revealed that DPP-4 inhibitors strongly were associated with onset rather than preventing aspiration pneumonia. This result suggests that DPP-4 inhibitors may affect the immune function associated with the development of aspiration pneumonia. Furthermore, there is a possibility that the amount of DPP-4-Is used clinically cannot increase the amount of substance P in sufficient quantity to prevent aspiration pneumonia.