I m 3rd yr medical student. and studies are really hard. i get sleepy all the time. any recommended medicine to increase attention span n performanc?

Few options: Provigil (modafinil) has minimal side effects and help with wakefulness. Caffeine can be overcome by fatigue too easily. 5-hr energy / red bull / monster type energy drinks can be used in moderation (like one in early afternoon as start to "fade" out). Unfortunately, best answer is good time management and adequate sleep.

No: Medication may keep you up longer to study but it will not help with retention of information, comprehension, and attention span. You need to follow a strict schedule of studying and sleeping at least 6-7 hours per day (8 better). Take breaks every 2-3 hours for about 15 min where you do something physical and don't think about school at all. No phone, texting, email.