Coffee can be consumed while taking Modvigil, although caution is advised. Since both modafinil and caffeine are stimulants, combining them may exacerbate side effects including anxiety, a fast heartbeat, restlessness, or difficulty falling asleep. Large doses of coffee can exacerbate adverse effects and make the medicine seem overpowering, although little quantities are often tolerated. See how your body responds when you start with less caffeine than normal. When using Modvigil, cut back on or stay away from coffee if you experience anxiety or jitters.