Aspirin - blood thinning

[MrPahoehoe]

I'm currently suffering from some haemorrhages in my right retina, related to a 'blocked' vein. I've been told to take aspirin daily, to thin the blood. I've just been reading up on my condition and the aspirin. Seems that the blood thinning properties are usually found at low dosages (e.g. 75mg), but I've been told to take 300mg per day (one tablet) - is this too much to thin the blood? (admitedly, i'm not a 'small person' - 6ft2" and 85kg, so I guess relatively its not that much of a high dose).
Cheers, MrP

[MrPahoehoe]

Oh, should say that the research suggested that the blood thinning qualities weren't present at higher doses. I'm not worried about the side effects of taking a higher dose, think I can cope with that in the medium-term, I'm worried about it not effectively thinning the blood....
Thanks again!

[Sqad]

I am confused, the dose of Aspirin is not body mass related, as the "stickiness" of the blood platelets is reduced with 75mgms..............larger doses do not "unstick" them more.

Take the 300mgms a day advised by you Dr..........can't do any harm.

[mallam]

Well sqad, I think it did me harm. I was put on 300mg per day after a minor MI and left on it for decades, in spite of being given iatrogenic gout (diuretics) and asthma (beta blockers), and being put on Anturan 400mg p.d. (now obv thought too much for maintenance). This may interest you as I am apparently quite a curiosity for still being on such an antique drug, but it seems to suit me.

However when computers started throwing up drug interactions on the prescription labels, they said it was incompatible with aspirin. I looked into this and I think it was something to do with their more or less cancelling each other out, but I was told not to bother my little head about it. So I had a slight stroke.

Then the practice nurse noticed I had been on 300mg aspirin from before the beginning of time and put me on 75mg. In due course I fetched up with cardio again, and my man seemed unfazed by that combination but banned any other NSAIDs and tried to get my shrink to put me on something less likely to enhance my status as a walking (not any more!) textbook of catastrophe theory. The shrink was more concerned about self-inflicted catastrophe, but since I had my massive internal haemorrhage has consented to try to see me through as a non-compliant.

Everyone agrees I should stay off aspirin now, and seems to think that 200mg of Anturan p.d. would always have done the trick just as well, and still ward off attacks that would put me back in NSAID territory. Not that that stops me making myself horribly ill with Tramadol and such for generalized OA and neuropathy (NBG, but no more Neurontin tyvm!)

Any comments?

[Sqad]

mallam.......i am going out for lunch now and you post will need a lot of thought......give me time.

[mallam]

I do hope I'm not spoiling your lunchbreak. You are bound to thin Im not worth it if I come clean on my own height and weight: 6'2" and shrinking fast, and seesawing between 15 and 19 stone all my life(16 at present) - never one of the 4% who manage to get it down and keep it down, and sceptical as to whether any but the morbidly obese of the other 96% would not be better off with a diet that merely stops them getting any heavier!

You may look more kindly on me if you goto my misposted encomium here:
http://www.theanswerbank.co.uk/Arts-and-Literature/Arts/Question811568.html

[Sqad]

mallam

" I was put on 300mg per day after a minor MI" …….no big deal so far…particularly if there were enteric coated

It has been found that the stickiness of the platelets to aspirin may be reduced and doses of asprin above 75mgs may be needed…e.g 300mgs……………no problem so far.

"in spite of being given iatrogenic gout (diuretics) and asthma (beta blockers), and being put on Anturan 400mg p.d. (now obv thought too much for maintenance). This may interest you as I am apparently quite a curiosity for still being on such an antique drug, but it seems to suit me."

It is not the best idea to combine Aspirin with Anturan, but if you get away with it….fine….medicine is not an exact science.

Anturan may be an old drug in the treatment of gout, but still very effective.

If I have missed your point, please let me know

[LazyGun]

Going back to the original question - Aspirins anti-thrombotic mode of action is not to "thin the blood". Rather, it reduces the risk of clot formation by reducing the ability of platelets to aggutinate and form the "mesh" of a clot. Aspirin manages this by inhibiting the production within the body of prostaglandins and more importantly, thromboxane, the agent most associated with the "stickiness" of platelets.It achieves this by inactivating cyclo-oxygenase, or rather one form of cyclo-oxygenase, COX1. other Non Steroidal Anti-Inflammatory Drugs (NSAIDS) act on the same mechanism, which is why it is important to be aware of other drugs being taken.

As far as the most appropriate dose to achieve this anti- thrombotic effect is concerned - many trials have been performed over the years, the largest and best controlled one being the ASPECT trial, which established the value of taking aspirin prophylactically in high risk patients. Other trials have looked at the dose requirements, and have found that this anti-thrombotic effect can be achieved with doses as low as 40mg daily. Higher doses will inhibit the COX pathway to a greater extent,although you are up against the law of diminishing returns, and additionally it has been hypothesised that aspirin works on other pathways to achieve plalelet inhibition, since there is some clinical observations to suggest that higher doses work better in certain classes of patients.
In summary, best clinical practice for anti-thrombotic activity of aspirin, maximising the COX inhibition and reducing the risk of bleeding disorders, is for a daily dose to be around 75-150mg daily.
300mg daily is not that much more, relatively speaking, so will certainly offer the anti- thrombotic effect just as well as a lower dose.
If it was me, and bear in mind that I am a pedant when it comes to stuff like this, I would want to ascertain from your medical professional why they want y

[Sqad]

mallam......I have just read your link re. cheesefreak.

Don't be too hard on her as my bedside manner has always been questioned on AB. However you soon learn in medicine that you can never be all things to all people and I feel it is too late to give my bedside manner an MOT.
It has done me fine so far in life.....LOL
Thanks for your support.

[Sqad]

lazy...thanks, you have put it in a more professional way than my effort.

[mallam]

Many thanx, sqad (esp. for not taking up the gauntlet of my metabolic syndrome).

Afraid you are having a particularly busy day on here. You can't be going having scruples about missed MOTs of your bedside manner. I think someone was in need of your seervices re diabetes on this forum. I was meaning to go back and try to say someting
helpful about my own experience of that.aspect of my metabolic syndrome too.

"It is not the best idea to combine Aspirin with Anturan, but if you get away with it….fine….medicine is not an exact science.

Anturan may be an old drug in the treatment of gout, but still very effective.

If I have missed your point, please let me know "

Well sqad you have rather. I did not get away with that combo. And the harm I said I think it did me was the massive internal haemorrhage I mentioned. Admittedly that was after my aspirin dose was down to 75mg, but I think it was the cumulative effect of decades of 300mg p d and the unnecessarily high maintenance dose of Anturan, which of course is also an anti-platelet drug, plus all the other drugs the cardiologist had tried to ban or query. I think the last straw was prob Diclomax, which I was told was the only thing that was really likely to get me over a persistent throat swelling. I was admonished to 'use it sensibly' and in fact hardly used it at all, but that's how last straws operate, isn't it?

Now the only possibly problematic thing I am on is the reduced dose of Anturan, 200mg, and as I say, that is to avert more problematic medication. Im grateful that you say you still think that very effective. Perhaps even for the prophylaxis the aspirin was originally intended for?
I had decided not to say this, but you see how I do go on, and it may be less alarming for the OP than I thought, since you say the 300mgms a day advised by you Dr..........can't do any harm.
You hav

[mallam]

You have seen why I'm not entirely sure of that, but with particular respect to the eyes, and the OP's talk of 'thinning the blood' to treat 'haemorrhages' related to a 'blocked' vein, which I find a bit puzzling, my own aspirin dosages have in part been motivated by eye problems attributed to severe narrowing of the retinal arteries (a 'window on the entire vascular system'). And when the hospital at first tried to put me back on the minimal 75mg after my internal haemorrhage, it gave me a black eye with dramatic speed. Another 'window on the entire vascular system'? Of course the bleed was periorbital in this case, but nobody seemed to think I should persist with the aspirin!

BTW I may have asked this before, but I think I would have remembered your answer. Does your sobriquet mean you were military as well as medical?