It knocked me out for about 3 hours today. I\’ve never experienced such drowsiness from a medication before. I\’ve felt like I was sinking into my … Even if taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Make sure you know how you react to this medicine … Dr. Philip Miller answered … NO: this is not a usual side effect of naproxyn. Dr Rhoads and another doctor agreed. If you become drowsy, dizzy or light-headed after taking NAPROXEN, do NOT drive or operate machinery. NAPROXEN may cause you to become more sensitive to … Quais são os usos do naproxeno? · Analgésico para febre leve a moderada. · Colica menstrual. · Dor de cabeça causada por enxaqueca e sinusite. · Dor de dente. This medicine may cause some people to become drowsy. Even if taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Make sure …