Rapidly emerging occurrence of micropollutants in aquatic systems has increased their potential to alter aquatic foodwebs. In addition to direct effects, micropollutants elicit indirect effects in tolerant species that can either be density-mediated or trait-mediated through changes in biomass or behavior of competitors and predators. In environment, aquatic organisms are continuously exposed to a pool of various classes of micropollutants at concentrations ranging between ng/L to µg/L. It is critical to evaluate combined effect these contaminants pose to aquatic ecosystems. In this study, ecological relevance of combined effects caused by pharmaceuticals and microplastics, two ubiquitous micropollutants in Anthropocene are being investigated. Given their ability to cause direct and indirect effects in aquatic organisms individually, we hypothesized a synergistic effect on aquatic organisms and associated trophic interactions. More specifically, decrease in ecosystem functions, such as biomass production and decomposition rate. Considering it prevalence in aquatic systems, fluoxetine hydrochloride -a psychoactive drug was chosen. Experiments were performed in 9 indoor mesocosms called limnotrons with 845L water and 40L sediment. Microplastics(diameter:10.23µ) were spiked into sediment and water at environmentally relevant concentration of 529 spheres/Kg dry weight and 19 spheres/L respectively. Concentration of fluoxetine in water phase varied from 10 to 500 ng/L. Limnotrons were monitored for 100 days at 20°C with 16:8(L:D) light regime. Parameters such as phytoplankton and zooplankton composition, decomposition rate were monitored along with fluoxetine hydrochloride, dissolved and particulate nutrients and dissolved oxygen (mg/L). Preliminary results indicate fluoxetine hydrochloride to play a crucial role in biomass accumulation and decomposition rate.