The level of contamination of the aquatic environment with residues of drugs as metoprolol, enalapril and metformin is constantly increasing. One of the reasons is the increasing prescribes and uses of these drugs, second is imperfect purification in wastewater treatment plants. Since the pharmaceuticals are entering water bodies continuously, they represent a potential risk for non-target aquatic biota. In our study, the toxicity of metformin, metoprolol and enalapril on zebrafish (Danio rerio) embryos in five different concentrations was tested. The acute toxicity test was performed according to OECD Guideline No. 236: Fish Embryo Acute Toxicity Test. The aim of this experiment was to study toxic effects of typical drugs used for treatment of diseases of affluence as diabetes, cardiovascular diseases and hypertension on fish early life stages. Metformin is the most common drug used to treat type II. diabetes, metoprolol and enalapril are used to treat diseases of the cardiovascular system and hypertension. The results showed that the tested substances had a negative effect on hatching of embryos at all tested concentrations and also they have influenced mortality and heartbeat.

Keywords: zebrafish; toxicity tests; development; mortality