According to different studies carried out by the United States Federal Aviation Administration, possible causal links have been found between fatal accidents and the consumption of first-generation antihistamines. The fundamental aim of this project is to analyze through a study with pilots, how the consumption of over-the-counter flu medicine affect their flight performance. We collected the data using a static flight simulator. Eight pilots with more than 150 hours of flight experience completed specific tests exposed to a consumption of first-generation antihistamines or a placebo. A two-factor ANOVA test confirmed that the consumption of first-generation antihistamine does influence pilot performance (p<0.05). Through observation, we found that pilots decreased their capacity to remember basics activities and their ability to react in an emergency in flight.