If you’re a safer driver when you take your medication, you should always be on it when you drive, day or night. But try to time your dose so that it wears off by the time you go to bed. For example, if you need to drive between 8 and 10 p.m. and want to go to sleep by 11 p.m., you might take a four-hour dose at 6 p.m. If any dose, especially one taken much earlier in the day, causes sleep problems after it should have worn off, ask your doctor about using a different medication.