More on Nitrous Oxide and Meperidine in Pain Care
Thank you for your responses to my letter about a patient whose back pain was “cured” after a dental procedure where he received meperidine (Demerol) and nitrous oxide.1 I suspected that these two drugs would in some way “realign the stars” but I have not seen much published data regarding the effect on N-methyl-D-aspartate (NMDA) receptors or oth-er mechanisms of changing central nervous system (CNS) plasticity.
It is interesting that most anesthesiologists have never really considered the use of nitrous oxide during pain injection procedures. Perhaps we should take a lesson from our dental colleagues. The most common nerve-related surgery performed in the US it dental root canal surgery. Patients seldom experience issues of long-term pain after oral surgery. It is my understanding from discussions my own dentist that they usually use fentanyl, midazolam, and nitrous oxide in less that 70% concentration. The duration of the procedure is generally 1 hour. I may consider this [recipe] in the future [for the management of] complex regional pain syndrome patients or others that I think may have pain
In regard to Demerol, this seems more interesting. Like you, I have seen patients that report that only Demerol helps to reduce their pain when other opioids do not seem to help. I am not sure if this has to do with a different μ receptor activation or some other mechanism, but as an addiction specialist I also suspect other factors. I can’t help but wonder if the metabolite normeperidine has an interesting and yet unknown pharmacological effect.
Again thanks for your response. I enjoy your insight and discussions. I will let you know if I discover anything regarding the above.
—Scott Hompland, DO
Dear Dr. Hompland,
I find your theories and observations to be cogent if not profound. I have long believed that the malignment of meperidine is misplaced. Some centralized pain patients find it their only relief— and seizures simply don’t happen in everyone.
Thanks for informing all of us about nitrous oxide, and its use in dental surgery. Lets hope that someone else will see this fascinating exchange and weigh in. Send in more of your thoughts and observations. We need a dozen more like you!!
—Forest Tennant, MD, DrPH