Equivalent dose tables are available when switching route or changing drugs. Tolerance occurs when increased doses are needed to maintain an effect. Physical dependence is return of pain when the opiate is cut back. Neither is addiction. Start with a brief intravenous course of an opioid but the oral course is better.
Some patients use self controlled dosage devices.
You push a button for an immediate IV dose. Depression, anger, and anxiety can develop and aggravate pain and can be treated. Pleasant diversion and vigorous exercise help as they increase the inborn production of pain killers called endorphins or enkephalins. The keys to good treatment are careful pain charting, early treatment, ongoing assessment, and clear doctor-patient communication. If all else fails, pain nerves can be temporarily or permanently blocked.