Fluoxetine is an SSRI and is used to treat major depressive disorder. Cymbalta contains duloxetine which is an SSNRI. Fluoxetine is better than duloxetine in side effect profile. Duloxetine causes vision changes, dry mouth, drowsiness, dizziness, tired feeling, loss of appetite and increased sweating. Common fluoxetine side effects include insomnia, strange dreams, headache, dizziness, vision changes, tremors, feeling anxious or nervous, weakness, yawning, loss of appetite, nausea, vomiting, diarrhea, dry mouth, sweating, changes in weight or appetite, stuffy nose, sinus pain, sore throat, flu symptoms, decreased sex drive, or difficulty having an orgasm etc. Duloxetine is more likely to cause problems if you drink alcohol or you have high blood pressure. Fluoxetine is more energizing than other antidepressants, but may not be the best choice for people who have trouble sleeping. I hope this information will help you Thanks!!