I switch from cymbalta (duloxetine) 90mg to zoloft 50mg when i stop the last dose of cymbalta (duloxetine) 30mg i get insomnia what could bi the reason ? and what i do

Cymbalta (duloxetine) withdrawal : Or Cymbalta (duloxetine) discontinuation syndrome. There are various Cymbalta (duloxetine) withdrawal symptoms. Insomnia is only one of the many. Hope it helps.

It would be best if your medication is managed by a Psychiatrist. If you are not confident with your doctor please see another for a second opinion. If you are not feeling well you may need a physical exam to find out if you are ill. Your Doctor may recommend a sleep study.