Instructed patient and caregiver about Tramadol. It is an opioid pain medication used to treat moderate to moderately severe pain. Serious side effects of Tramadol may include: seizures, increased risk of serotonin syndrome, decreased alertness, and drug addiction. Common side effects include: constipation, itchiness and nausea, etc. A change in dosage may be recommended in those with kidney or liver problems.