The medicine Odep increases the levels of chemical messengers in the brain that help in regulating the mood and treat depression. The usual side effects are Sleepiness, Blurred vision, Increased heart rate, Dry mouth, Constipation, Weight gain, Difficulty in urination, Orthostatic hypotension (sudden lowering of blood pressure on standing). Your headache may not be due to Odep, talk to your doctor who is treating you for depression or neuropathic pain, who will be the right person to modify the dosage, if required.