2. Definition of Anticoagulation Therapeutic interference
("blood-thinning") withthe clotting mechanism ofthe blood to
prevent or treat thrombosis and embolism. 3. ANTICOAGULATION :are
given to prevent and reat thrmbo-embolic disease but thereare many
use , ANTICOAGULATION are used to treat severalcardice or vascular
disease disordes including1-a trial fibrillation2-cardiac valvular
disease3- prosthetic cardiac valves4- isachaemic heart disease and
post- myocardial infarction5- (some times), deep venous
thrombosis,pulmonary embolism6- cerebrovasucular accident and many
other . -the long used anticoagulation are the coumarin warfarin
for long termtreatment and heparin for short term treatment . 4.
because it takes several days for the maximumeffect of warfarin to
be realized ,heparin given first.The plasminogine activators such
as tpa (altplase)or streptokinase also are useful for
controllingcoagulation ,in particular during period aftermyocardial
infarction .because tpa is highly selectivefor the degradation of
fibrin in clots ,it is extermlyuseful in restoring the latency of
coronary arteriesafter thromposis. 5. Some pt on anticoagulant
drugs haveatendency to bleeding after trauma orsurgery .Dental
preventive care especially importantto minimize the need for
surgicalintervention-may can cause problems alternatives.Systemic
conitions that may aggravate thebleeding tentency. 6. Drug that
might worsen the bleedingtenency (aspirin &other
NSAIDS).Intramuscular injections should beavoided& regional
block injections mayalso be hazardConscious sedation can be given.
7. Indications of Anticoagulant Therapy1-Treatment and Prevention
of DeepVenous Thrombosis2-Pulmonary Emboli Prevention of stroke
inpatients with atrial fibrillation, artificialheart valves,
cardiac thrombus.3-Ischaemic heart disease.4-During procedures such
as cardiaccatheterisation and apheresis. 8. The four methods by
which the dentist can identify the patient who mayhave a bleeding
problem are listed below. Skills acquired through applicationof
these methods determine how well dentists can protect certain
patientsfrom the dangers of excessive bleeding after dental
surgical treatment. Thesefour methods consist of the following: A
good history Physical examination Screening clinical laboratory
tests Observation of excessive bleeding after asurgical procedure
9. ANTICOAGULANTS Three classes:1-Heparin and Low MolecularWeight
Heparins (e.g. dalteparin)2-Coumarin Derivatves
e.g.Warfarin,3-Indandione Derivatves e.g.Phenindione, Anisindione
10. WARFARIN (also used as rat poison) andother coumarin drugs
(such asphennindione) inhibitcoagulation by antagonizingvitamin K.
11. Warfarin: Major Adverse Effect Haemorrhag 12.
INTRODUCTIONWarfarin is the most commonly prescribed oralanti-
coagulant. At present over 300,000 people in theUK are taking oral
anticoagulants and the treatmentis underused in some conditions.
With an ageingpopulation in the UK and a greater proportion of
thispopulation retaining their teeth, the number ofpatients taking
warfarin who require dentalextractions is likely to increase. 13.
.Therapeutic levels of warfarin are measured by theInternational
Normalised Ratio (INR). The British Societyof Haemotology has
published guidelines onanticoagulant control which recommend a
maximumtarget INR of 3.5, with a range of For dental
extractions,patients who have been taking warfarin are at an
increasedrisk of perioperative thromboembolism if the drug
isstopped but may be at an increased risk of bleeding if it
iscontinued. 14. Managing patients who are taking warfarin
andundergoing dental treatment: If patients on warfarin who require
dental surgeryhave an International Normalised Ratio (INR) ofbelow
4.0, they can usually receive their dentaltreatment in primary care
without needing to stoptheir warfarin or adjust their dose.. The
risk of thromboembolism after temporarywithdrawal of warfarin
therapy out weighs the riskof oral bleeding following dental
surgery.. Patients on warfarin may bleed more thannormal, but
bleeding is usually controlled withlocal .measures 15. Warfarin
does not need to be stopped before primary care dental surgical
procedures.Are patients at risk of thromboembolic events if
warfarin is stopped? Stopping warfarin for two days increases the
risk of thromboembolic events This risk is difficult to estimate
but is probably between 0.02% and 1%It has been common in primary
care dental practice to discontinue warfarintreatment for a few
days prior to dental surgery in order to limit bleedingproblems. It
has been assumed that stopping warfarin for a short periodpresents
a negligible risk to the patient. 16. Are patients at increased
risk of bleeding if warfarincontinues?Yes. Treatment with warfarin
impairs clotting and consequently patients have anincreased risk of
bleeding during surgical procedures and post-operatively. Bleeding
in themouth can be excessive, even in non-anticoagulated patients.
This is because the toothsupport structures are highly vascular .If
warfarin is continued what is the incidence of
postoperativebleeding and is it clinically significant?Continuing
warfarin during dental surgical procedures will increase the risk
of postoperativebleeding requiring intervention.Stopping warfarin
is no guarantee that the risk of postoperative bleeding
requiringintervention will be eliminated as serious bleeding can
occur in non-anticoagulated patients.Most cases of postoperative
bleeding can be managed by pressure or repacking andresuturing the
socket.The incidence of postoperative bleeding not controlled by
local measures varies from 0% to3.5%. 17. Clinically significant
postoperative bleeding has been defined12 h as that which;
Continues beyond 12 hours, Causes the patient to call or return to
the dental practice or accident and emergency department, or
Results in the development of a large haematoma or ecchymosis
within the oral soft tissues, or Requires a blood transfusionThe
following medical problems may affect coagulation and
clotting:liver impairment and/or alcoholismrenal
failurethrombocytopenia, haemophilia or other disorder of
haemostasisthose currently receiving a course of cytotoxic
medication. 18. When should the INR be measured before a
dentalprocedure?The INR must be measured prior to dental
procedures, ideally this should bedone within 24 hours before the
treatment However, this is difficult toachieve in primary care
dental practice. For patients who have a stable INR,an INR measured
within 72 hours before the procedure is acceptable.Patients will
need either to co-ordinate their dental treatment with their
nextplanned INR measurement or have an extra INR measurement within
72hours of their planned dental treatment..The INR is valid only
for patients who have stable anticoagulant therapy.Patients
presenting with an INR much higher than their normal value, even
ifit is less than 4.0, should have their procedure postponed and
should bereferred back to the clinician maintaining their
anticoagulant therapy. 19. Advice to be given to patients: Advice
for patients is available in the patient leaflet, Oral
Anticoagulant Therapy: Important information for dental
patients*Dental surgery covered by this advice includes:Treatment
where the INR does not need to be checked: Prosthodontics
Conservation EndodonticsTreatment where the INR does need to be
checked : Extractions Minor oral surgery Periodontal surgery
Biopsies 20. What is the normal INR range?The activity of warfarin
is expressed using the international normalised ratio (INR).For an
individual not taking warfarin a normal coagulation profile is an
INR of 1.0.Pulmonary embolus (PE)2.52.0-3.0Deep vein thrombosis
(DVT)2.52.0-3.0Atrial fibrillation 2.52.0-3.0Recurrence of embolism
- no longer on warfarin2.52.0-3.0Recurrence of embolism on
warfarin3.53.0-4.0Mechanical prosthetic heart
valves3.53.0-4.0Antiphospholipid syndrome 3.53.0-4.0 21. Which
patients taking warfarin shouldnot undergo surgical procedures
inprimary care?Patients who have an INR greater than 4.0 should not
undergo anyform of surgical procedure without consultation with the
clinician who isresponsible for maintaining their anticoagulation
(this may be the GP orthe hospital anticoagulant clinic
haematologist). The warfarin dose willneed to be adjusted prior to
the procedure. Patients who aremaintained with an INR >4.0 or
who have very erratic control may needto be referred to a dental
hospital or hospital based oral/maxillofacialsurgeon. 22. Should
the primary care dentist ever advise an alteration to the
warfarinregimen? No. The GP or the anticoagulant clinic must do
this.For what procedures can warfarin be continuedsafely?Minor
surgical procedures can be safely carried out without altering the
warfarin dose.Those likely to be carried out in primary care will
be classified as minor e.g. simpleextraction of up to 3 teeth,
gingival surgery, crown and bridge procedures, dentalscaling and
the surgical removal of teeth . 23. -When more than 3 teeth need to
be extracted thenmultiple visits will be required.-The extractions
may be planned to remove 2-3teeth at a time, by quadrants, or
singly at separatevists.- Scaling and root planning should
initially berestricted to a limited area to assess if the
bleedingis Problematic. 24. >If acute infection is present,
surgery should be avoided untilthe infection has been treated. When
the patient is free ofacute infection and the INR is 3.5 or less,
minor surgery canbe performed. The procedure should be done with as
littletrauma as possible. The American College of Chest Physicians
and the American Heart Association/American College of Cardiology
also recommend that warfarin therapy should not be interrupted for
invasive dental procedures, and that a tranexamic acid(Cyklokapron)
or EACA (Amicar) mouthwash should be applieduring the first 2
postoperative days to help control excessive bleeding. 25. Are
there any drug interactions that are relevant to this patient group
undergoing dentalsurgical procedures? Amoxicillin - There are
anecdotal reports that amoxicillin interacts with warfarin causing
increased prothrombin time and/or bleeding but documented cases of
an interaction are relatively rare. Clindamycin - Clindamycin does
not interact with warfarin when given as a single dose for
endocarditis prophylaxis. Metronidazole - CAUTION metronidazole
interacts with warfarin and should be avoided wherever possible. If
it cannot be avoided the warfarin dose may need to be reduced by a
third to a half by the GP or anticoagulant clinic. Erythromycin -
Erythromycin interacts with warfarin unpredictably by only
affecting certain individuals. Most are unlikely to develop a
clinically important interaction. Patients should be advised to be
vigilant for any signs of increased bleeding. 26. Paracetamol The
anticoagulant effect of warfarin is normally not affected, or only
increased by asmall amount, by occasional doses of paracetamol.
Paracetamol is considered to be safer than aspirinas an analgesic
in patients taking warfarin and is the analgesic advised by
anticoagulant clinics and thepatient held Anticoagulant therapy
booklet. The anticoagulant effect of warfarin may be enhanced
byprolonged regular use of paracetamol.Aspirin AVOID use as an
analgesic and anti-inflammatory agent. Concurrent aspirin
increasesthe likelihood of bleeding by 3-5 times, increases the
bleeding time and may damage the stomachlining.42 The interaction
is well documented and clinically important.Non-Steroidal
Anti-Inflammatory Drugs (NSAIDs) - AVOID NSAIDs e.g. ibuprofen,
diclofenac.Care should be taken when using NSAIDs in patients on
anticoagulant therapy due to the increased riskof bleeding from the
gastro-intestinal tract.Rofecoxib (COX-2 inhibitor) Patients should
be closely monitored if rofecoxib is used. Inpatients on chronic
warfarin therapy treatment with rofecoxib has been associated with
an increase inINR values. Although rofecoxib can increase the risk
of gastro-intestinal bleeding, this risk is less thanwith standard
NSAIDs and rofecoxib may be considered a safer option. Close
monitoring is important inthe first few days of rofecoxib therapy
and patients should be advised to be vigilant for signs ofincreased
bleeding. 27. Local anaesthetic:A local anaesthetic containing a
vasoconstrictor should beadministered by infiltration or by
intraligamentary injection.Regional nerve blocks should be avoided
when possible.However, if there is no alternative, local
anaesthetic should beadministered cautiously using an aspirating
syringe .Localvasoconstriction may be encouraged by infiltrating
asmallamount of local anaesthetic containing
adrenaline(epinephrine) close to the site of surgery . 28.
HeparinHeparin is a parenteral anticoagulant, which is oftenused
for acute thromboembolic episodes orforhospitalizatio protocols
that include significantsurgical procedures. Heparin is
administeredsubcutaneously or intravenously to prevent deepvenous
thrombosis and pulmonary emboli. 29. Most patients treated with
standard heparin arehospitalized and will be prescribed warfarin
oncedischarged. Dental emergencies in these patientsduring
hospitalization should be treated asconservatively as possible,
with avoidance of invasiveprocedures, if possible. Patients treated
withhemodialysis are given heparin. The half-life ofheparin is only
1 to 2 hours; thus, if they wait untilthe day after dialysis, these
patients can receiveinvasive dental treatment. 30. Antiplatelet
DrugsPlatelets are an important contributor to arterial
thrombi.Antiplatelet treatment has been reported to reduce
overallmortality from vascular disease by 15% and to reduce
nonfatalvascular complications by 30%. Aspirin, the
prototypicalantiplatelet drug, exerts its antithrombotic action by
irreversiblyinhibiting platelet cyclooxygenase, preventing
synthesis ofthromboxane A2, and impairing platelet secretion
andaggregation. Aspirin is the least expensive, most widely used,
andmost widely studied antiplatelet drug. NSAIDs such as
ibuprofenand indobufen act as reversible inhibitors of
cyclooxygenase. 31. Salicylic acid (SA) irreversibly decreases
plateletaggregation and is used chronically in the preventionof
cardiovascular events and stroke in patients atrisk. In large
doses, SA may caus hypoprothrombinemia.Even small doses of SA
increase the bleeding.time and decrease platelet adhesiveness 32.
VITAMIN K DEFICIENCY.Deficiency of factors II, VII, IX, X, protein
C, protein S Causes: 1.Decreased vitamin K intake. 2.Decreased
production of vitamin by gut flora(antibiotics) 3. Poor absorption
- sprue, biliary obstruction, etc 4.Inhibition of vitamn K action
(warfarin, certainantibiotics)Treatment: vitamin K (oral or
parenteral)
