Since 1995 - Non Profit Healthcare Advice

Local Anesthetics Don`t Work On Me



Many years ago when I had a wisdom tooth taken out the dentist gave me several injections before the are would become numb, and then it only lasted for maybe 2-3 minutes. I never thought anything about it until I had my first child and the epidural did not work, I had a team of anesthesiologists in my room who after repeated attempts could not get it to work. I don`t know what was more painful the birth or feeling the epidural needle. After the birth of my second child where the epidural did not work again, I had to have surgey and upon waking up found out that I have an immunity to Morphine,Demerol and Coedine, as none of these drugs worked on me at all. That was a fun thing to have to find out after a major surgery! The only pain drug they gave me that worked was Torridol.

After this surgery I found out that my grandfather and an Aunt have the same problems. Pain drugs and local anesthetics do not work on them either.

My grandfathers docotor told him that he thinks his body produces and enzyme, almost like its an allergic reaction to the anesthetic and it attacks it immediately and breaks it down so that it does not localize.

In the past year I`ve had a small area of skin cut off for biopsy and a finger stitched up where once again after several shots the area still did not get numb and I had to bear the pain as they had no other alternative to numb me for these minor procedures. I`ve spoken with my family doctor who seems to be stumped for an explanation of this. I`m trying to find out if there is a name for this condition or any information about it before I need another surgery or minor procedure done, as doctors tend not to believe me until after a half dozen injections I can still feel their needle or razor blade. Minor procedures I`ve tolerated pretty well but if something serious were to happen i`d like to be able to explain it better so I could justify them putting me to sleep for something they normally would do a local anesthetic for.



Thanks for your very interesting question.

It’s very difficult to explain your problems with a single “defect” or condition.

Local anesthetics work on cell receptors called sodium channels and it is possible that you have an altered form of sodium channel which makes you resistant to the effects of local anesthetics. There are two different groups of local anesthetics – amides and esters, and you should ask your doctors to make sure they try at least one from each group.

There are also people who have different endorphine receptors – these are the receptors for morphine, and other narcotic (pain-killer) drugs. However morphine and Demerol have completely different structures and it’s hard to explain why you would be resistant to both of them. There are other narcotics that may not have been tried in your case, such as fentanyl, alfentanil and sufentanil, so your doctors could perhaps try those. Finally, there are genetic variations in the way people break down and get rid of drugs like codeine, which can dramatically affect the dose need to get pain relief.

Receptors might not be the problem at all, rather some abnormality of pain perception or of conduction (nerve) pathways. Do you have increased sensitivity to painful things, or things that would not ordinarily cause pain? Are you taking any other medications that might affect your perception of pain? Are there any other medications to which you have had an unusual response? These are questions your doctors might want to ask, and if you want to pursue it further you could go to the anesthesia department in your local academic medical center to find out whether anyone would like to help you get to the bottom of this interesting and unusual problem.

For more information:

Go to the Anesthesia health topic.