Combination of tramadol with full opioids?

Re: Combination of tramadol with full opioids?

Matt Gurney — Thu, 15 Apr 2010 16:52:17 GMT

Methadone is a useful opioid in cats. It is a pure mu agonist and unlike morphine is demethylated (like fentanyl). It also has NMDA actions (like ketamine) which makes me select it over morphine. I would be careful with a lido cri in a cat. Not much difference between therapeutic and toxic plasma levels.

Try 0.3mg/kg meth q4hrs.

Re: Combination of tramadol with full opioids?

Hanna Bennett — Wed, 14 Apr 2010 15:25:13 GMT

[quote user="Jon Bray"]

You'd have thought so, wouldn't you? According to my nurse the infusion pump couldn't go down that far (she did try) and trying to turn the drip rate down any further using the manual dial just caused it to stop completely. Given the inherent inaccuracy of doing things manually (plus lack of experience with it) I was reluctant to add medetomidine or lidocaine to the CRI - in retrospect I should have put less ketamine in the bag in the first place.

[/quote]

Bless, sounds like a bad day came calling!

We use fentanyl patches a lot and I think they are the bee's knees. Tend to find in cats they kick in within 3-6 hours of placing them, and be aware that they may still need top up analgesia, but gen very nice as it also means less mucking about with them to give other drugs. We have done major surgeries on a number of cats with the patch placed a sufficient amount of time prioir to surgery (usually admit them the night before for elective jobs) and find they wake up purring and hungry!

Re: Combination of tramadol with full opioids?

Jon Bray — Tue, 13 Apr 2010 22:38:34 GMT

[quote user="Hanna Bennett"]Ketamine CRI can be altered to rate surely [/quote]

Not really used the fentanyl patches - I think we might have some in stock though so will remember that for next time.

Re: Combination of tramadol with full opioids?

Laurence Webb — Tue, 13 Apr 2010 20:37:54 GMT

My understanding was that a lot of the effects of morphine is due to it being broken down into active metabolites which are more potent than the morphine itself. As cats have strange livers they don't produce the active metabolites and therefore don't get as much analgesia from it as dogs or humans do. This is what makes buprenorphine a more effective analgesic than morphine in this species.

In that situation I'd probably have stuck a fentanyl patch on and managed the pain via buprenophine with a ketamine +/- lidocaine infusion until the patch kicked in. I've found very few occasions when a fentanyl patch doesn't do the job. Very low doses of alpha 2 agonists can be helpful although sedation can be a problem, especially as you're probably sticking it in with a mix of other sedative drugs

Re: Combination of tramadol with full opioids?

Hanna Bennett — Tue, 13 Apr 2010 19:43:30 GMT

granted, vetergesic is now supposed to be pretty good analgesia in cats but if that's not working i would go for a stronger opioid before adding in oral meds. Ketamine CRI can be altered to rate surely - just means putting a fair few days worth in the bag - we have infusion pumps not syringe drivers but it works for us.

Re: Combination of tramadol with full opioids?

Jon Bray — Tue, 13 Apr 2010 17:32:23 GMT

Thanks all.

Bit surprised that they use amitryptilline with tramadol - thought serotonin syndrome was an issue. Maybe that's just with the SSRIs though.

Reason I asked was that we had a cat in a few days ago with a broken leg which still seemed uncomfortable on vetergesic - I added a ketamine CRI which seemed to do the trick but left it pretty zonked - and there isn't much scope for fine adjustment of the rate with those unless you happen to have a syringe driver or are giving "surgical" rates of fluids.

Re: Combination of tramadol with full opioids?

Laurence Webb — Sat, 10 Apr 2010 22:42:12 GMT

I've not had to use the two at the same time but I know that you can do so in humans if neccessary - my wife had been on dihidrocodeine for a long time and, following a diagnosis of fibromyalgia was started on Tramadol at a standard dose and told that she could withdraw the codeine at will as there was no contraindication to using them together. She's also on meloxicam and amitryptilline at the same time.

Interestingly she was given steroids whilst on all this lot (on omeprazole anyway) without even a word of warning about intestinal ulceration. I wonder where her subsequent weight loss and iron deficiency anaemia come from!

If I had to use it alongside a opitate in animals I'd probably start at 2mg/kg bid and increase to 5mg/kg tid as required. Most of its effects are non-opiate related such as 5HTP inhibition so I'd not panic about interactions too much if the pain was severe enough to warrant it.

Re: Combination of tramadol with full opioids?

Hanna Bennett — Sat, 10 Apr 2010 20:54:18 GMT

daft question, but when would you want to? We use injectable/intradermal opioids in hospitalised patients, and tramadol for analgesia at home. Trying to think of a case when I would use both but i can't but appreciate that i may be being thick!