taking ketamine whilst on warfarin?

[captaintom]

A friend of mine is currently taking warfarin to prevent blood clots, in several weeks we will both be attending a gathering at which various substances will be taken. My friend knows that taking MDMA is out of the question as is using other uppers (mephedrone, coke etc.) but I could not find any information on potential interactions with ketamine. Although I may very well be wrong, I have a feeling I have heard in the past of people who have been given medical doses of ketamine (much higher than recreational) whilst on warfarin and suffered no ill effects. Would it be safe for my friend to use ketamine (insufflated) whilst still taking warfarin? Some answers would really be appreciated here, thank you.

 

[pharmarat]

Interesting question I had a look around and couldn't find anything too specific (just the medical doses you referred to), but it would seem that both ketamine and warfarin are metabolised by some of the same liver enzymes (e.g. Cyp2C9). This could potentially increase or decrease the plasma concentrations of warfarin, though I haven't found anything more informative than that. So they do interact, it's really just a question of how much - that will depend on the doses of both warfarin and ketamine. Would he be having his INR tested shortly after this event?

 

[Foreigner]

It would be more useful to let us know why your friend is taking warfarin.

 

[RTrain]

^He said for blood clots. Kind of vague but I'd guess a history of DVT if its a relatively young person.

 

[captaintom]

he's taking the warfarin after having abscesses in his lung and neck removed. while we're on the topic, does anybody know whether taking MDMA would be dangerous whilst on warfarin? it really is frustrating how little there is online about potential interactions with warfarin and recreational drugs, obviously if we can't find out anything then my friend will not take anything but it'd be hugely helpful if some safe combinations could somehow be worked out.