Quick help required - Can someone please explain this interaction to me....

[Altered Perception]

I need quick help because I have a really bad ear infection at the moment and its effecting my balance and I have been throwing in the last 2 hours because of how nauseating I feel from my head spinning , so I was about to take an anti-nausea medication named Zofran (Ondensatron) but I've already taken Tramadol and when I checked online so see if there was an interaction between the two I read that there is but I cant understand the article so please someone explain what sort of an interaction is this talking about....

5-HT3 Antagonist Anti-Emetics + Analgesics

The best known interaction here is the one described between ondansetron and tramadol. Two RCTs showed increased tramadol consumption and reduced ondansetron efficacy with the use of the combination. Tramadol consumption was increased by 40-50% in both studies, while the efficacy of ondansetron as an anti-emetic seems to be affected, too. The authors conclude, that ondansetron should not be the first line anti-emetic when tramadol is used.

The observations are most likely best explained by a combined pharmacodynamic and a pharmacokinetic interaction between the two drugs. From a clinical point of view the combined use of tramadol and ondansetron should be avoided; we prefer low-dose droperidol anyway for cost reasons. It is possible, that other 5-HT3 antagonists do not necessarily share this problem; in particular granisetron and dolasetron are more selective 5-HT3 antagonists than ondansetron and granisetron is not metabolised by CYP450 2D6.

http://www.anzca.edu.au/fpm/events/...ram/drug-interactions-in-pain-management.html

 

[Altered Perception]

All I wanted to know was does the word "Tramadol consumption was increased" mean the Ondensatron made the Tramadol more intense or decreased its effects?

 

[Pegasus]

^ It seems to me to mean that patients had to take more tramadol, and that other anti-emetics should be used first when tramadol is being taken... I'll move this over to ADD to verify though.

 

[sekio]

That's what I'm reading out of it, too.

 

[Altered Perception]

Thank you Moderators for your help. I had a high fever, confusion and dizziness at the time I posted this and I couldn't make any sense of the article, but reading it again now I understand it much better but thank you for explaining it.

 

[negrogesic]

From the standpoint of its use as an anti-emetic, mirtazapine, while technically contraindicated (in practice, dose dependent), appears to be well tolerated in patients using tramadol for pain. Note; conceptually a similar interaction is likely, as tramadol efficacy would be possibly reduced from a pharmacological standpoint, as tramadol's analgesic properties are in part attributed from monoaminergic activity. I am honestly not sure as to any major pharmacokinetic concerns, but I don't have the numbers in front of me. Just an observation. It is also important to note that coadm of tramadol and mirtazapine does carry a theoretical risk of hypertensive crisis, but is one of the few anti-d's i would personally be relatively comfortable using in concert.

Mirtazapine as a whole is not a first-line anti-emetic due to considerable CNS-activity, but is used when others are poorly tolerated.

 

[Altered Perception]

Thanks so much for sharing that useful bit of information, I am fairly sensitive and I do often have problems with tolerating drugs and substances in general due to my damaged Autonomic Nervous System so your suggestion is very helpful.

 

[laCster]

tramadol and mirtazapine both inhibit 5HT-2c causing the seizure threshold to drop. clonic tonic seizures would be the likely result