Background/Objectives: Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly associated with gastrointestinal (GI) adverse events. This study aimed to assess the incidence and patterns of NSAID-induced GI disorders using the FDA Adverse Event Reporting System (FAERS) database and to compare the risks among different NSAIDs. Methods: NSAID-related reports were extracted from FAERS, focusing on 21 ulcer-related GI events with ≥1000 reports each, based on MedDRA v26.0. The number of reports, reporting odds ratios, and p-values were calculated and visualized using a volcano plot. Principal component analysis(PCA) was carried out to reduce the dimensionality of the dataset and revealed under-lying patterns in the data.PCA was performed to identify patterns related to risk, severity, and injury site, whereas hierarchical clustering was used to group NSAIDs based on these patterns. Hierarchical cluster analysis is a method of grouping similar data to generate a classification. Results: Statistically significant signals were identified for 19 of the 21 GI-related adverse events, including the serious condition of perforation. PCA revealed that the first component represented risk, the second severity, and the third the site of injury (upper vs. lower GI tract). Cyclooxygenase-2 (COX-2) selective NSAIDs (e.g., celecoxib, rofecoxib) were associated with a lower incidence but greater severity, primarily in the upper GI tract. Conversely, nonselective NSAIDs (e.g., acetylsalicylic acid, lornoxicam) showed higher incidence rates, though the events were generally milder. In our dataset, acetylsalicylic acid had the highest incidence, whereas meloxicam showed the highest severity. Clustering analysis revealed three distinct NSAID groups with differing patterns in risk, severity, and affected GI site. Mild adverse events may be underreported in FAERS. Dosage-related effects were not assessed in this study. Conclusions: NSAIDs differ significantly in their gastrointestinal adverse event profiles, attributable to COX selectivity. When selecting an NSAID, both the likelihood and the nature of potential GI harm should be considered.

Background/Objectives: There exist multiple opioid-based treatments in palliative care, each with distinct side effect profiles. When adverse events occur, switching opioids can help maintain effective pain management. However, owing to limited clinical evidence, no comprehensive guidelines exist for opioid switching. This study employed the Side Effect Resource (SIDER) database, which aggregates adverse event data from clinical trials and package inserts, to analyze the side effects of five commonly used “strong opioids” in palliative care in Japan, namely morphine, fentanyl, oxycodone, hydromorphone, and tapentadol. Methods: Data on the names and incidence of adverse events for each opioid were extracted from SIDER 4.1, developed by the Max Delbrück Center for Molecular Medicine. Cluster analysis and principal component analysis were performed to interpret the data. Results: The key side effects of opioids were nausea, vomiting, constipation, and drowsiness. Fentanyl was more frequently associated with nausea and vomiting but less frequently with constipation and drowsiness. Tapentadol caused nausea relatively more frequently and constipation less frequently. Oxycodone was prominently linked to drowsiness, whereas morphine was frequently associated with constipation and drowsiness. Hydromorphone was associated with higher rates of constipation and vomiting but lower incidences of nausea and drowsiness. Conclusions: All side effects characterizing the opioids were related to μ-opioid receptor stimulation, although the present study findings highlight differences in the frequency of specific side effects among the opioids. These results provide objective insights that can guide opioid switching in response to adverse effects.

Conclusions: NSAIDs differ significantly in their GI adverse event profiles, influenced by COX selectivity and dosage. Both the likelihood and nature of potential GI harm should be considered when selecting an NSAID.

Background/Objectives: Opioid-based treatments in palliative care involve multiple options, each with distinct side effect profiles. When adverse effects occur, switching opioids can help maintain effective pain management. However, owing to limited clinical evidence, no comprehensive guidelines exist for opioid switching. This study employed the Side Effect Resource (SIDER) database, which aggregates adverse event data from clinical trials and package inserts, to analyze the side effects of five commonly used “strong opioids” in palliative care in Japan: morphine, fentanyl, oxycodone, hydromorphone, and tapentadol. Methods: Data on adverse event names and incidence rates for each opioid were extracted from SIDER 4.1, developed by the Max Delbrück Center for Molecular Medicine. Cluster analysis and principal component analysis were performed to interpret the data. Results: The key side effects for the opioids were nausea, vomiting, constipation, and drowsiness. Fentanyl was more frequently associated with nausea and vomiting but less often with constipation and drowsiness. Tapentadol caused nausea relatively more often and constipation less frequently. Oxycodone was prominently linked to drowsiness, whereas morphine-induced constipation and drowsiness more frequently. Hydromorphone was associated with higher rates of constipation and vomiting but fewer incidences of nausea and drowsiness. Conclusions: All the side effects characterizing the opioids were related to μ-opioid receptor stimulation, although the present findings highlight differences in the frequency of specific side effects among the opioids. These results provide objective insights that can guide opioid switching in response to adverse effects.