January 5, 2011
This questions brings up two important topics: what does warfarin do and what are the consequences for tooth removal or any other oral surgical procedures. Let’s take them one at a time – we’ll paint these topics with a broad brush in order to give you some guidelines.
Warfarin as you probably know is a potent blood thinning medication
and is used for a variety of medical conditions as an anti-coagulant –
as the name implies to stop blood from clotting. It is usually given
to people with an increased tendency for thrombosis (blood clot
formation inside blood vessels) or to prevent of further clots in those
who have had them before. It helps prevent the serious risk of heart
attack and stroke that these clots can pose. Common conditions for
which warfarin is used include atrial fibrillation (the heart’s two
upper chambers, fibrillate or beat out of normal rhythm); deep venous thrombosis (clotting in the deep leg veins) and pulmonary embolism (blood clots moving into the lungs). Anti-coagulant therapy
may also be given as a preventive measure in patients who have
artificial heart valves and on a short-term basis to those who have had
surgeries, such as knee replacements.
For a person of any age, but especially as you get older your health
status is important and needs to be evaluated carefully along with many
other clinical or medical factors to make sure you are healthy enough
to undergo surgery, even oral surgery for tooth removal.
It should also be pointed out that the commonly used drug aspirin is a
potent blood thinner and many people forget or don’t know to tell
their doctors they are taking it before undergoing surgery. Now for the
good news – warfarin treatment is not a contra-indication to having teeth removed or for that matter, having them replaced with dental implants.
In other words one thing has nothing directly to do with the other.
Indirectly though, surgery for anyone on blood thinners can be
complicated because blood will not clot normally and it can be
difficult to stop bleeding. However, tooth removal usually constitutes
minor oral surgery, especially with a minimum of trauma or damage to
tissues, in careful and experienced surgical hands.
The surgeon who assesses your condition should work with your medical doctor to determine the risk and monitor your warfarin dosage
appropriately. The safety of maintaining, modifying or reducing your
warfarin dosage to accommodate tooth extraction or any other minor oral
surgery will depend on what condition you are taking it for,together
with the particular type of surgery you need.
The traditional measure of blood clotting is something called the Pro-thrombin Time (PT) and the International Normalized Ratio (INR).
It is quite conceivable that your medical doctor will reduce your
dosage based on the PT/INR levels,which together with local measures
(specially treating the surgical area) will ensure that you have
sufficient ability to stop bleeding and heal well. The key is
communication between your doctors and their experience and judgment. If
it is not considered safe for you to stop warfarin completely, an INR
of below 4 may be acceptable, between 2 and 3 is preferable, but these
are guidelines only and require a discussion between your physician and
For the surgical procedure related to tooth removal, your dental
surgical specialist (oral surgeon or periodontist), or general dentist
can take special precautions to help insure blood clotting and an
uneventful healing time after the surgery. These include treatment of
the surgical site with special hemostatic agents (haem –
blood, stasis – still) which helps stabilize a blood clot, then
carefully suturing (stitching) the gums to reduce the surface area of
the wound opening and putting tension on the wound edges to prevent the
capillaries (tiny blood vessels) from bleeding excessively. It is also
common practice today to place a bone graft into an extraction socket
to prevent the otherwise inevitable shrinkage of your bone, especially
important if you are contemplating implant tooth replacement. This
will also reduce the volume of bleeding.
Anti anxiety medications, good pain control and
anti-inflammatory medication, together with rest and avoidance of
vigorous activity will all help ensure a comfortable and safe
recuperative period, necessary for the first few days. You will be able
to resume warfarin (or aspirin for those who take it) almost
immediately afterwards, under the direction of your doctors.