The release of pharmaceutical products has increased in terrestrial and aquatic ecosystems, putting the biota at risk, being able to generate multiple impacts on organisms, from modifying enzymatic expression to intergenerational impact on exposed organisms. This study evaluated the influence of phenobarbital and ibuprofen on tolerance to the insecticide temephos in two populations of Aedes aegypti, La Esperanza (LE) and Rockefeller (Rock). Larvae I were exposed to 17.7 μg/ml ibuprofen and 200 μg/ml phenobarbital until reaching stage III; subsequently, larvae mortality to temephos (0.005, 0.025 and 0.050 μg/ml) and the enzymatic activity of esterases were determined. Phenobarbital was found to favors a higher tolerance to 0.025 μg/ml of temephos, at 24 hours of exposure, in the LE population (44.00 ± 6.93% mortality) as opposed to Rock (97.33 ± 2.67% mortality); furthermore, it d...