Yes, one of the common side effect of Doxylamine+Vitamin B6 (Pyridoxine) is drowsiness. Do not drive, operate heavy machinery or engage in other activities that need your full attention. Do not drink alcohol or take any medicines that may depress the central nervous system like cough and cold medicines, certain pain medicines, and medicines that help you sleep, while you are taking Doxylamine+Vitamin B6 (Pyridoxine). Severe drowsiness can happen or become worse and may cause falls or accidents.