Hi, Conrado.

I think that this articles will be useful for your investigation. First of them, Goyenechea Jaramillo et al., (2006) concluded that withholding buprenorphine therapy 6-8 hours before anaesthesia incorporating pure mu receptor agonists is probably advisable. Alternative methods of analgesia should be provided in this period.

In the second one, Andaluz et al (2008) published the pharmacykinetics of buprenorphine in dogs after a single intravenous bolus.

Kindest regards

https://www.ncbi.nlm.nih.gov/pubmed/17083612

https://www.ncbi.nlm.nih.gov/pubmed/18467137

Conrado,

I find your question interesting due to the limited choice. My suggestion is to look at other interventions, such as peripheral nerve blocks, epidural infusion, ketamine infusions, etc. Fentanyl will work to control immediate uncontrolled pain but will not be the most definitive way to address the postoperative pain issue.

Thank you very much! I have read all those papers but https://www.ncbi.nlm.nih.gov/pubmed/18467137 because I only had access to the abstract. I found the answer I was looking for. I hope more bibliography come soon in this line because I want to know why is secure to give opioids while a treatment with buprex but not buprex while you are using opioids. 

Conrado,

The reason one can give fentanyl to a patient experiencing unrelieved pain while receiving Buprex is due to the agonist effect of the fentanyl. Buprex functions as an agonist/antagonist. When a patient is receiving moderate or high dose fentanyl (or other opioid agonist) when Buprex (or other opioid agonist/antagonist) is administered the antagonist activity will increase the patients pain rather than improve it. Just as one would expect if administering naloxone.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3947912/

Regards

This has been studied in rats. If you email me I can send you the section in my Masters thesis on these drugs in particular. It depends on the order in which the drugs are administered and binding affinity. I also have a the ranking order of binding affinity for all opioids in the thesis as well.  We evaluate the effects of buprenorphine on hydromorphone analgesia in cats if you want to read that manuscript. I believe i uploaded it on RG.

Dear mates: In this article you´ll find an excellent revision about this topic: The perioperative management of patients maintained on medications used to manage opioid addiction. Curr Opin Anaesthesiol. 2014 Jun;27(3):359-64.

CONCLUSION: "(..)Summary: When possible, patients maintained on buprenorphine should be evaluated preoperatively to assess the feasibility of discontinuing the buprenorphine 72 h before surgery. If buprenorphine is continued during the perioperative period, patients may require significantly increased doses of standard opioids for analgesia.(..)".

https://www.ncbi.nlm.nih.gov/pubmed/?term=curr+opin+anesthesiol+2014+27%3A359+-+364