Posted by Ame Sans Vie on August 16, 2003, at 15:36:15
In reply to Re: Parnate and Anaesthesia, posted by Caleb462 on August 16, 2003, at 13:58:12
> Why *is* anesthesia + MAOI risky? I don't understand the mechanisms behind this - care to enlighten me?
That's a good question... I believe that it may be due to the danger of life-threatening hypotension. I'll see if I can find some more info for you.
> Also - you say opiods are cautioned against while on MAOI therapy, but it was my understanding that only those which also block monoanime reuptake (Demerol, Ultram, etc) need to be avoided. For instance, I see no reason why MAOI + hydrocodone would be a problem.
Once again, good question. Demerol should definitely be avoided while on MAO inhibitors, but sources seem to vary in their opinions on the use of other narcotics concomitantly with MAOIs. Here are a few examples of what these sources say with regard to specific narcotics together with MAO inhibitors:
"Mosby's Drug Guide for Nurses":
alfentanil -- do not use [MAOIs] within 2 wk of alfentanil
buprenorphine -- do not use [MAOIs] 2 wk before buprenorphine
butorphanol -- do not use [MAOIs] 2 wk before butorphanol
codeine -- use with caution
fentanyl -- do not use [MAOIs] 2 wk before fentanyl
hydrocodone -- do not use [MAOIs] for 2 wk before taking hydrocodone
hydromorphone -- serious reactions; dosage should be reduced
levorphanol -- increases respiratory depression
meperidine -- do not use [MAOIs] for 2 wk before taking meperidine
methadone -- do not use [MAOIs] for 2 wk before taking methadone
morphine -- reduce dosage; unpredictable reaction may occur
oxycodone -- do not use [MAOIs] for 2 wk before oxycodone
oxymorphone -- do not use [MAOIs] for 2 wk before oxymorphone
pentazocine -- use cautiously; results are unpredictable
propoxyphene -- use decreased dosage; reaction is unpredictable
remifentanil -- (no interactions listed for MAOIs)
sufentanil -- do not use [MAOIs] 2 wk before sufentanil
tramadol -- inhibition of serotonin and norepinephrine reuptake; use together with cautionhttp://www.nlm.nih.gov/medlineplus/druginfo/uspdi/202054.html
Medline only warns against the use of meperidine with MAOIs; it never even makes mention of the others.
http://www.nursespdr.com/members/database/ndrhtml/phenelzinesulfate.html
Just says that all narcotics should be used with caution while on MAOI therapy. It also lists general anesthetics as causing an increased hypotensive effect, so I suppose I was correct in my earlier assumption.
http://www.sma.org/smj/97aug14.htm
"ADVERSE INTERACTIONS between the monoamine oxidase inhibitors (MAOIs) and anesthetic drugs are well recognized. Although controversial, the most current recommendation pertaining to patients who, while taking MAOIs, require surgery and anesthesia suggests that the MAOI can be continued perioperatively as long as meperidine is avoided."
So it's pretty obvious that there's no real consensus yet as to which narcotics are "okay" while on MAOIs. Though it seems to me that "Mosby's Drug Guide for Nurses" may be a little overly conservative, as I've personally spoken with an anesthetist about this very issue, and he says he's never had any problems inducing anesthesia on MAOI patients with morphine, fentanyl, alfentanil, or sufentanil; and though the book says not to use hydrocodone or propoxyphene during MAOI therapy, I used them with no problems while on very high-dose Nardil. I imagine this means I also could have used oxycodone, codeine, and probably methadone (since it's related to propoxyphene) with no problems.
I guess the important thing is to avoid meperidine at all costs, and to just take it slow with any other narcotic.
poster:Ame Sans Vie
thread:250988
URL: http://www.dr-bob.org/babble/20030812/msgs/251368.html