How do you get rid of insomnia induced from dexedrine (dextroamphetamine)?

Stop the drug: If you are taking an amphetamine rx'd by a dr. I'd assume they dx'd adhd.If you are experiencing insomnia i'd question the dx(diagnosis) or you may be taking a dose too late in the day.

For dieting?: Change to another med is one solution. In the meantime use excellent sleep hygiene. 1. Keep a regular bedtime & wakening time (to include weekends). Get up the same time each day, regardless of what time you fell asleep. 2. Make a regular, relaxing bedtime routine. Relaxing rituals prior to bedtime may include a warm bath or shower, aroma therapy, reading, or listening to gentle music.