Hello, Your doctor has prescribed you Nucynta which contains Tapentadol which is central acting analgesic used to treat moderate to severe pain.It is very effective and comparable to other opioid analgesics like pethidine,oxycodone etc.It has advantages over opioid analgesic that it causes lesser side effects. The main side effects include nausea,vomiting,constipation,dizziness which are less as compared with other central drugs. Secondly about pain pump,its a relatively newer technique to control the pain by patient himself whenever he feels pain.It has some instructions to learn.Its safe if used properly as per guidelines. Hope this helps.Take care. Thank you