Characterizing pharmacobezoar formation: a descriptive analysis from VigiBase

Pharmacobezoars are concretions of drugs that can persist within the gastrointestinal tract and can lead to mechanical obstruction and pharmacological toxicity. We aimed to provide a descriptive analysis of reported cases of pharmacobezoar in VigiBase, the World Health Organization global database of adverse event reports for medicines and vaccines.

We conducted a descriptive analysis of all de-duplicated individual case safety reports related to pharmacobezoars recorded in VigiBase, from its inception in 1968 to March 2, 2025. In a subgroup analysis, we selected reports containing at least one Preferred Term related to drug overdose, misuse, or suicidal behavior to identify potential cases of acute intoxication.

A total of 632 individual case safety reports related to pharmacobezoars were analyzed. These primarily involved male patients (n = 318; 50.3%), with a median age of 60.0 years (IQR 43.0-71.0 years). Overall, 432 reports (68.4%) described serious adverse drug reactions. The most frequently involved drugs were carbidopa/levodopa (n = 148; 23.4%), quetiapine (n = 63; 10.0%), sucralfate (n = 46; 7.3%), nifedipine (n = 41; 6.5%), and acetylsalicylic acid (n = 40; 6.3%). The subgroup analysis included 158 reports related to acute intoxications, mostly involving female patients (n = 103; 65.2%), with a median age of 43.0 years (IQR 24.0-54.0 years). Almost all were serious (n = 156; 98.7%), with quetiapine, venlafaxine, ibuprofen, acetylsalicylic acid, paracetamol, and lorazepam most frequently reported.

The findings highlight the clinical severity and heterogeneous presentation of pharmacobezoars. Carbidopa/levodopa was frequently reported, possibly reflecting underlying conditions such as Parkinson disease with delayed gastric motility. The high prevalence of psychotropics underscores the need for targeted prevention in at-risk populations, particularly those with psychiatric comorbidities.

While pharmacobezoars are rare, their association with serious and potentially fatal outcomes warrants increased clinical awareness. Early recognition and appropriate management may be particularly important in cases involving high-risk drugs.