Here is an excellent example of why I can never recommend anyone go on Acenocoumarol.
https://www.revespcardiol.org/en-co...arin-articulo-S1885585715003485?redirect=true
They write
However, VKAs are not exactly equivalent. Genetic polymorphisms are affected differently according to the type of VKA. The CYP2C9 isoenzyme would appear to be more important for warfarin clearance than for acenocoumarol or phenprocoumon clearance.
1 Although warfarin is the most widely used VKA, in some countries, acenocoumarol or phenprocoumon are used.
In Spain, the most widely used VKA is acenocoumarol. However, most of the available evidence on the efficacy and safety of VKAs is derived from warfarin. The results obtained with this VKA have in general been extrapolated to the other VKAs.
So extrapolated means "guessed at"
Lets dive into this a bit: first the basis of their test is so pathetic that no actuary would accept it :
The objective of the present analysis was to determine whether there were differences in the clinical profile, anticoagulation control, and thromboembolic/bleeding events according to type of VKA. A total of 1524 patients were included. Of these, 79 (5.2%) were taking warfarin (1127 international normalized ratio [INR] assessments; 14.4±0.12 assessments/patient) and the rest were taking acenocoumarol (94.8%).
so absolutely statistically insignificant number of participants for comparison.
Then we get to the key point of "time in range" Their (seemingly this is good enough) time in range was for acenocoumarol:
Variable | Acenocoumarol (n=1445) | Warfarin (n=79) | P |
|---|
Time in therapeutic range (direct method), % | 61.1±0.59 | 64.3±2.0 | .57 |
Time in therapeutic range (Rosendaal method), % | 67.9±0.58 | 68.3±2.1 | .72 |
absolutely miserable times in range and made to look better by comparing it to substandard times in range of warfarin. Time in theraputic range for warfarin should be in the high 80's for a clinic and for a self manager in the 90's. I myself am on average 95% in range.
Worse (and undiscussed) is that on Acenocoumarol the half life is around 8 hours, so a missed dose will have you absolutely un-anticoagulated for a day. << Not ideal
They say themselves:
In terms of efficacy and safety, no randomized trials have compared these 2 alternatives.
so why would you even pick the drug? I can only assume because its a national health system and the government saves money in the short term.
They observe in discussion:
Although the design of our study does not allow determination of the reason for prescribing warfarin or why these differences in prescription vary according to autonomous community, given the difference in half-life of the VKA, the physicians may have switched to warfarin because of inadequate INR control with acenocoumarol.
Ya think? So Catalonia (which had the highest use of warfarin) may have switched to warfarin because the (largely wealthier) people there were worried about strokes. Possible IMO.
Then they identify what I identified but defend it because "it reflects our malpractice"
The main limitation of this study is the small sample size with warfarin, thereby reducing the statistical power of the comparisons. However, this situation reflects what occurs in clinical practice in Spain, where warfarin use is very limited.
Myself I don't even think its good rat posion because its half life is too short.
Then they write this:
The study was sponsored by Bayer Hispania S.L. The sponsor had no influence on study conduct or data collection and interpretation.
So the drug company selling them this 5h1t sponsors it? No influence except perhaps to add in that above bit I bolded.
Lastly if you look up the references supporting this drug in their reference section you'll see the author of this papers names come up ... odd isn't it.
Indeed one of their supporting papers wrote this:
https://pubmed.ncbi.nlm.nih.gov/8191397/Since there is no evidence that acenocoumarol is more efficacious or safer than warfarin, the latter seems to be preferable for patients who are candidate to very prolonged OAT
...and as we're on it for life I'd call that prolonged OAT.
Keep in mind there are many reasnsons why Oral Anticoagulation Therapy are prescribed, many are short term, some are long term. Of the long terms it would include DVT, Stroke history, Atrial Fib and Mechanical Valve Replacement. I would argue of all of those, the only one which will suffer from regular dips in INR is mechanical valve replacement where low INR may well cause thrombosis covering of the valve leading to valvular obstruction by those clots sticking to the leaflet.
I recommend you listen to this:
