Remifentanil and tramadol.

The lack of analgesic efficacy limits tramadol as a sole agent to treat severe pain after surgery. However, it has a relative lack of respiratory depressant and constipating effects compared with morphine and codeine, and does not share the propensity of nonsteroidal anti-inflammatory drugs to provoke asthma, gastrointestinal mucosal damage and renal impairment. It may well have a place in the management of pain after surgery, in combination with another drug, such as paracetamol, or after control of the worst of pain after surgery by a regional local anaesthetic technique.