A blood thinning aspirin tablet
Blood thinning medicines (Antiplatelet agents, Anticoagulants) and vasectomy…
Blood thinning medicines (Antiplatelet agents, Anticoagulants) and vasectomy is a common issue raised by patients. Patients are on anticoagulants for a variety of reasons and in many cases it may not be safe to stop them. Find below some answers to your questions. This article may also help patients awaiting other surgical procedures.
Which blood thinning medications will this article cover?
The principles discussed in this article are true for all blood thinning medications, but there are specific issues that will be discussed in specific sections. Apart from Aspirin the article will cover Clopidogrel, Dabigatran, Apixaban, Rivaroxaban, Warfarin and others. Even if your personal blood thinning medication is not mentioned it is worth reading on. We also cover Dual Therapy, this means you are on 2 blood thinning medications and we finally give you some advice on self care while stopping blood thinning medications.
Click below to jump to those sections:
- Aspirin and Clopidogrel (Antiplatelet medicines, often after heart attacks)
- Dual Therapy (2 blood thinning medicines at the same time, often after heart valves and stents)
- Apixaban, Rivaroxaban and Dabigatran (Anticoagulants, often for irregular heartbeats, blood clots and strokes)
- Warfarin (older medicine where no other medicines are licenced or due to patient choice. Extremely well tolerated, mixes with most other medicines well. Easier to work with when patients have surgery)
- General Considerations: General advice about pros and cons of stopping blood thinning medicines
- Top Selfcare Tips: Read this section if you are on any blood thinning medicine.
Aspirin (and Clopidogrel)
What does Aspirin (Clopidogrel) do?
Aspirin and Clopidogrel are Antiplatelet agents, blood thinning medications that avoids blood clotting by irreversibly inhibiting platelet aggregation in your blood. Platelet half time in your blood is 5 days. Thus, after 10 days still roughly 25% of your platelets cannot aggregate. You can see, how long it takes for the effects of Aspirin to reduce its effect.
Benefits of Aspirin:
Secondary Prevention: By reducing the ability of your blood to clot you can improve circulation in areas that are poorly circulated, for example after heart surgery a stroke or a heart attack. Thus, you take it, because a health event has already occured.
Primary Prevention: However, there are also people that take Aspirin for Primary prevention (no previous problems, but a choice) for example 50-70 year olds according to the recommendation of the US FDA as Aspirin is an effective cancer preventer.
What else can I do to avoid clotting:
Thick blood clots quicker than thin blood, so for example being well hydrated is a good way of avoiding more blood clotting than necessary and I would recommend anyone choosing to stop Aspirin before Minor surgery that they always ensure to be well hydrated while Aspirin (or Clopidogrel) is stopped.
Is Vasectomy Minor Surgery?
Yes and No. While the procedure is definitely Minor Surgery the side effects of a bleed are significantly more pronounced because the “skin turgor” of the scrotum is almost nil. This means the skin isn’t pressing on the wound to stop bleeding like for example on the arm or leg. Thus, a scrotum can more easily fill up with blood and takes longer to absorb. Aspirin and vasectomy is definitely a specific issue.
Should I stop Aspirin (Clopidogrel) before surgery? And when should I re-start?
In Major Surgery Aspirin (Clopidogrel) is generally stopped before surgery and replaced with Heparin. In Minor Surgery and vasectomy it depends as there is a balance to be struck between the bleeding risk and the risk to your safety.
Its probably not good to stop Aspirin if you are taking it for secondary prevention (i.e. due to a previous problem with your heart or brain). If you however take it for Primary Prevention you should strongly consider to stop Aspirin.
If you choose to stop Aspirin it doesn’t make sense to stop the day before as it wont work, you have to stop at least 10-14 days prior to the procedure and also not re-start while bleeding risk is increased i.e. a week after the procedure
How about Dual Therapy (taking 2 blood thinners at the same time)
If you are on 2 blood thinners at the same time you should not get a vasectomy in the community. You usually only take 2 blood thinners i.e. Aspirin and Clopidogrel for a year i.e. after a stroke. Wait until your consultant reduces you down to one blood thinner (which you will be on for life). Then come and see us.
Apixaban, Rivaroxaban or Dagibatran
Most of these blood thinners are important to avoid repeated blood clots and should not be stopped unless a medical specialist advises you to do so. However, their half life is quite short and often a short period of stopping can be agreed to with your doctor or specialist.
If your specialist agrees, I would recommend to stop them 2 days before your procedure (2-3 doses) and re-start 1-2 days after your procedure.
If you stop them you have a lesser chance of bleeding, but a higher chance of clotting. Please read below for top tips when stopping a blood thinning medication before surgery or any other procedure (vasectomy, dental procedures etc).
Warfarin
General Considerations considering vasectomy and blood thinning medicines
How high is my risk of clotting if I choose to stop Aspirin?
It is very important to be statistically savvy. Aspirin reduces the chance of blood clotting, it doesnt mean it stops you clotting. You can still clot while on Aspirin, but there is generally a 30% risk reduction. I.e. if 3 out of 100 patients would have a blood clot without Aspirin there would then be only 2 out of 100 patients having a blood clot once they take Aspirin.
In other words: Most patients stopping Aspirin will not get a blood clot, but run a slightly higher risk, but equally even if you are on Aspirin you still could get a blood clot.
If I have a procedure on Aspirin or another blood thinner, will I definitely bleed?
No. Most patients are absolutely fine, but occasionally we have had patients with longer stays and more problems. Statistically, your risk is higher, but that doesn’t mean you will have problems.
What should I do next?
For me as a doctor, it is very important for you as a patient to be well informed. That’s why I have written the above article. Based on this information we can then make a shared decision balancing risks vs benefit of stopping. In the end your decision is final. All I am asking you is that you consider the issues around blood thinning medications and Vasectomy. if you choose to stop Aspirin or any other blood thinners ensure your hydration levels are adequate throughout the time. If you choose to continue on blood thinning medicines I want you to not worry about it as we doing everything in our power to make your experience as good as anyone else’s.
Top self care tips for patients choosing to stop blood thinning medications.
- Don’t stop if your underlying diagnosis is serious (i.e. stroke). If you take them for a less problematic diagnosis i.e. an irregular heart beat, then the balance can occasionally lean more towards stopping. Speak to your specialist before you make any decisions.
- Speak to your doctor before stopping and ask them what they would do.
- If you decide to stop, make sure you are staying well hydrated and do not get dehydrated.
- Aspirin has a very long half life. No point stopping a day or 2 before. The half life is 5 days, so after 10 days you still have 25% of the power of Aspirin left in your blood.
- Clopidogrel, Rivaroxaban, Apixaban and Dabigatran have all short half lives. If your specialist agrees you can stop them a couple of days before and that’s fine.
- If you re-start too early after the procedure you could still bleed (unless it is Warfarin, which takes time to get into the system).
- Warfarin has a long half life and is also difficult to titrate up again. But if you normally on an INR level (Warfarin level) of 2-3 then perhaps discuss with the clinician managing your Warfarin going down to a level between 1.8 and 2.2 before vasectomy to reduce your chance of bleeding. Any level up to 2.5 is still reasonable. Between 2.5 and 3 the risks are higher and I would not recommend vasectomy in patients with an INR over 3.
- For information about Aspirin in Minor Surgery click here (very similar article, though)
- Dr M Kittel
- Most recent update: 10/02/2025
- 17:32
- Page first published: 14/07/2020