Evidence of Dual antiplatelet therapy in Dentistry
Posted on 5th November 2017 at 13:27
By: Antonio F. Gagliardi Lugo
Twitter: @AGL_ToX / @OdontoInfoLA
Antiplatelets medications are often used in patients following myocardial infarction, ischaemic stroke and ischaemic vascular disease, also it is indicated in patients for reducing the risk of thrombosis, especially in those who have undergone a coronary stenting procedure. It has been shown to prevent vascular events and even death in patients with peripheral vascular disease.
Before we continue, its very important to know the difference between anticoagulants and antiplatelets agents. Both are medicines that will decrease the clotting effect of the blood. The anticoagulants are commonly known by most patients as "blood thinners", their effect is more powerful in the coagulation cascade than that achieve by the anti-platelets. Examples of anticoagulants are warfarin, rivaroxaban or apixaban. The main focus of this article is only anti-platelets drugs such as aspirin and clopidogrel.
Anti-platelets treatments are mainly prescribed by cardiovascular doctors, careful patient selection is important before considering prescribing aspirin or clopidogrel (Plavix) on patients with peptic ulcers or known bleeding disorders and asthma. Aspirin should be avoided in children under 12.
Aspirin inhibits the metabolism of arachidonic acid by irreversibly inhibits cycloxygenase enzymes, preventing production of prostaglandins, responsible for mediating pain and inflammation, therefore acts as an anti-inflammatory, antipyretic and analgesic medicine. However due to its non specific mechanism, aspirin also inhibits prostaglandins responsible for platelets aggregation. Producing an inhibitory effect during the lifetime of the affected platelet (7-10 days).
Clopidrogrel after being activated by cytochrome P450 enzymes, works preventing adenosine diphosphate (ADP) from binding to its receptor on the platelet surface. The final outcome of this is irreversibly inhibition of platelet aggregation. There are other ADP receptor inhibitors such as Prasugrel, ticlopidine, cangrelor, elinogrel and ticagrelor. Clinicians have to be aware of the uses and complications that can arise with such medications, by referring to the British National formulary (BNF) before commencing any form of treatment.
Haemostasis is crucial for several dental procedure in periodontics, oral surgery and oral pathology, as bleeding problems can cause complications pre and post operatively. Patients on anti-platelets therapy represents a challenge to some dentist due to their increased risk of bleeding... But are they ?
An study published in the British Dental Journal, Volume 220, No5, March 2016 done by S. Nathwani and K Martin from the Department of Oral and Maxillofacial Surgery, Luton and Dunstable University Hospital throws some lights about this matter. They’ve conducted a literature review in January 2016 of free text and MESH searches of keywords: “aspirin, clopidogrel and dental extractions in the Cochrane library, Pubmed and CINAHL. Studies of all kind were selected to define the effects of dual anti-platelet therapy on the incidence of postoperative bleeding, and wheter this effects merits discontinuation of anti-platelets therapy before a dental procedure such as simple dental extractions.
Their findings are that despite limited evidence and inconsistencies in the results of the studies considered. The literature review highlighted that patients on dual anti-platelets therapy can be managed appropriately with local haemostatic measures and the discontinuation of the drugs should only be considered in conjunction with the prescribing physician. Their final recommendations for a safety practice are:
Not to discontinue any anti-platelet medication due to the risk of thrombotic event which outweighs the risk of post-operative haemorrhagic complications.
Provide verbal and written postoperative instructions, such as pressure pack over the surgical site, avoidance of physical exertion post-operatively and chewing on the opposite side of the surgical area.
Apply local haemostatic measures such as sutures and oxidized cellulose polymers for example surgical.
Appointment for extractions to be made in the morning and early in the week.
Intraoperative bleeding can be managed with local haemostatic measures such as oxidized cellulose, sutures, gauze pressure packs, acrylic splints and even tranexamic acid .
Consider staged extractions.
Consider preoperative blood and coagulation profiles where there is a risk of increasing bleeding, especially in vulnerable adults (elderly or those with existing co-morbidities).
About the Author:
Oral & Maxillofacial Surgeon. Gran Mariscal de Ayacucho University. Venezuela.
Dentist Degree. Santa Maria University Caracas, Venezuela
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