Anticoagulant medication interaction

[Mpharm_UEA]

Hi...Have not been on in a while as 3 days before uni started I developed a DVT and PE due to a suspected training injury in my leg. Took the hospital 4 weeks to arrange a CTPA scan (good old NHS) which revealed lots of little clots in my right lung.

Have just stopped the tinzaparin injections and will continue on warfarin for 6 months. I had a couple of questions which the doctors were unable to answer.
1) I have developed a rash on my face (realy red,flakey and itchy). Docs said use E45 cream...but its done nothing. What would you recommend?
2) Are there any interactions between warfarin and ephedrine HCL? Have looked in the BNF but no luck!

Thanks guys.

[Nikolai]

Regarding the second q ephedrine would come under sympathomimetics, and there is no mention of an interaction between coumarin anticoags and sympathomimetics.

[Mpharm_UEA]

Hi there and thanks for the reply. I have been reading up on the internet and came across the following statement:

"Sympathomimetics: anticoagulant effect of coumarins possibly enhanced by •methylphenidate"

It was from the following source:

http://gp.cardiff.ac.uk/documents/INRTesting.doc.

So you are saying that ephedrine is safe to take whilst on oral anticoagulation therapy with warfarin.

[Nikolai]

I was under the impression that methylphenidate acted by increasing dopamine levels and is not classed as a sympathomimetic. BNF does mention an interaction with methylphenidate but not with ephedrine or pseudoephedrine etc. Stockley's does not mention an interaction either.

[Web Ferret]

I can't see mention of interaction between ephedrine and warfarin anywhere.

[Mpharm_UEA]

Yeah I know....It's a bit of a grey area as anticoagulants are thought to enhance the actions of ephedrine, hence the use of aspirin in the ECA stack.

Thanks for the input.

[PHARMAC1ST]

The rash is most likely due to the initiation of warfarin due to a little sensitivity to it. I think it will usually get better as you continue the treatment.

The e45 cream is and emolient so would not actually make the rash go away but rather keep that area of the skin moist preventing it from drying out preventing further problems like flaking. If it remains a problem it would be a good idea to go back to the doctor who could possibly prescibe hydrocortisone cream.