Sulfamethoxazole (SMX) is a member of the sulfonamides group of antibiotics which is used extensively in aquaculture throughout the world. In this study, common carp (Cyprinus carpio) was used as the bioindicator to assess the toxicity potential of SMX. Effects were based on chronic toxicity of environmentally relevant dosages of 25, 50, 100, and 200 μg/L of SMX for 28 days. Cytotoxicity through hematology and biochemistry showed a dose–response relationship. Numerous variations were recorded in blood profile and biochemical parameters in SMX-exposed groups when compared to control. Hemoglobin, platelet, and erythrocyte levels were significantly decreased. Leukocyte level was significantly increased with values ranging from 131 to 303 (×10³/μL). Changes in biochemical indices: glucose, total protein, and triglycerides showed biphasic trend, but alanine transaminase secretion was significantly increased from 25.13 to 204 U/L at higher concentration compared to control, suggesting liver damage. Spectrophotometric nitroblue tetrazolium reduction assay showed that respiratory burst activity increased as a function of SMX dose and exposure time (0.48–1.33 absorbance) ultimately leading to reduction in immunity. The present study highlights that prolonged exposure of SMX affects biochemistry, hematology, and immunohematology of fish and these biomarkers act as an effective tool for environmental risk assessment of drugs in the aquatic environment.

磺胺甲基异恶唑（SMX）是磺胺类抗生素的成员，该磺胺类在世界各地的水产养殖中广泛使用。在这项研究中，鲤鱼（Cyprinus carpio）被用作生物指标，以评估SMX的潜在毒性。效果基于环境相关剂量的SMX 25、50、100和200μg/ L持续28天的慢性毒性。通过血液学和生物化学的细胞毒性显示出剂量-反应关系。与对照组相比，SMX暴露组的血液概况和生化参数记录了许多变化。血红蛋白，血小板和红细胞水平显着降低。白细胞水平显着升高，范围为131至303（×10 ³/μL）。生化指标的变化：葡萄糖，总蛋白和甘油三酸酯呈双相趋势，但与对照相比，高浓度的丙氨酸转氨酶分泌从25.13增加到204 U / L，提示肝脏受损。分光光度法测定硝基蓝四唑鎓的分析结果表明，呼吸爆发活性随SMX剂量和暴露时间（0.48–1.33吸收）而增加，最终导致免疫力降低。本研究强调，SMX的长时间接触会影响鱼类的生物化学，血液学和免疫血液学，而这些生物标志物可作为评估水生环境药物环境风险的有效工具。