Background Adverse drug reactions (ADRs) to sodium dimercaptosulphonate (DMPS) mercury removal treatment have been reported in occupational mercury poisoning. In recent years, the number of cases of mercury poisoning due to mercury-containing cosmetics has been increasing, and ADRs to the use of DMPS are common in clinical practice.

Objective To investigate the occurrence of ADRs and the influencing factors in patients with chronic mercury poisoning and mercury exposure treated with DMPS for mercury removal.

Methods Patients treated with DMPS due to mercury poisoning at the Occupational Disease Department of Nanjing Prevention and Treatment Center for Occupational Diseases from June 2017 to December 2023 were included in the study. Information on demographics, baseline characteristics, and treatment regimens was collected at admission. Information on secondhand smoke, place of residence, and blood groups not collected at admission was collected in follow-up. The patients were divided into two groups according to whether ADRs occurred after the use of DMPS and were compared for clinical characteristics, and the influencing factors related to the occurrence of ADRs after DMPS treatment were analyzed by binary logistic regression.

Results A total of 72 patients were enrolled in the study, of which 26 reported ADRs during mercury removal. A total of 29 ADRs occurred, mainly rash in 11 cases (37.9%), fever in 5 cases (17.2%), and nausea in 4 cases (13.8%). Most ADRs occurred in the second course (7 cases, 26.9%) and the third course (9 cases, 34.6%). Of the 22 non-menopausal women who experienced ADRs, 13 (59.1%) used DMPS in the week prior to menstruation. The logistic regression analysis showed that smoking (OR=27.911, 95%CI: 2.835, 725.809) and blood type O (OR=6.885, 95%CI: 2.014, 26.896) were associated with elevated occurrence of ADRs after DMPS treatment.

Conclusions The probability of ADRs after DMPS treatment is not low, but mild presentations are predominant and resolved with immediate treatment, with a favourable prognosis. The O blood group, smoking individuals, and female patients using DMPS one week before menstruation may be more prone to ADRs.