Metanalysis of Tramadol included 19 PBO-RCTs, 6506 pts, showing a very modest benefit on chronic pain (low certainty of evidence), but a doubling of risk for serious adverse events (OR 2.13); including nausea (NNH 7), dizziness (NNH 8), constipation (NNH 9), somnolence (NNH 13) https://t.co/0ZEIoy1gqC