The duration of Demerol's pain relieving effects is shorter than other narcotics and its production of toxic metabolites make it an inferior medication for pain control. Demerol also has a long list of potentially dangerous interactions with other medications. For these reasons, Demerol is now less frequently used to treat pain.
Demerol can be toxic when high doses are used and has a long list of side effects which include:
Respiratory depression (slowed breathing)
Dizziness, lightheadedness
Blurred vision
Low blood pressure
Tremors or seizures
Rapid heart rate or abnormal hear beats
Nausea and vomiting, among others.
Yes, tolerance can happen with any narcotic (although not all patients experience it).
I believe the main reason most docs don't prescribe demerol in pill form is research has shown that it does not have the pain relieving ability in that form that it does in IV or IM form and the pain relief is usually very short lived - 2-3 hours as opposed to 4-6 hours for other short acting narcotics.
but a tolerance happen's in every drug taken. and if your in pain,what are you suppose to do. just stop and continue being in pain?
Doctors are often reluctant to prescribe demerol because its a narcotic pain pill, and therefore can be addictive, and it has a potential for mis-use. I'm not saying you are planning to abuse it or are addicted to it, but it does happen so doctors are cautious.
Also, tolerance, (if taken regularly) builds quickly, so more and more is needed for the same pain killing properties of it.
Hope this helps.