W14 49 anticoagulants, steroids, insulin Flashcards
What drugs affect clotting?
Aspirin
Clopidogrel
Heparins
Warfarin
Non-vitamin K oral anticoagulants (NOACs)
Thrombolytics (not used much anymore’
What are the problems with anticoagulants for dentists?
- excessive bleeding after oral or periodontal surgery
- modification of regimen might predispose patients to thromboembolic events
- danger of drug interactions
Assess benefit vs harm = clot vs bleed balance
What considerations are there for bleeding risk?
High vs low risk of bleeding from treatment
Lifelong or limited treatment
Bleeding history
What effect does aspirin have?
Antiplatelet effect. Lasts 7-10 days (life of a platelet)
What mechanism does aspirin work by?
Irreversible cyclo-oxygenate (COX) inhibition. Prevents thromboxane A2 production.
What are the uses of aspirin and usual dose?
Uses - stroke, TIA, ischaemic heart/peripheral vascular disease
Dose - 75mg (baby aspirin) to 300mg daily
What are the problems with taking aspirin in dental patients?
Increased bleeding time
Problems of oozing from sockets
May require increased local haemostatic measures
What other Antiplatelet drugs are there?
Clopidogrel, dipyridamole, prasugrel and ticagrelor
What does clopidogrel do?
Selectively inhibits ADP-induced platelet aggregation (by PY12 receptor inhibition)
What does stopping Antiplatelet mono therapy do?
Stopping anti-platelet therapy increases the risk of stroke or MI (especially if recent coronary stent). Patients are more at risk of permanent disability or death if Rc stopped prior to a procedure than if they continue it. Bleeding complications are inconvenient but not as risky to life.
What should you do for patients on anti-platelet dual therapy?
Treatment with aspirin and clopidogrel increases bleeding time more than either alone. Might need to consult with cardiologist and treat at hospital-based clinic, potentially will say to go back on aspirin only for a little bit.
What are heparins?
Not oral anticoagulants
What does unfractionated heparin do? Describe its effects and when to use it. (RARELY USED!)
Inactivates multiple coagulation factors. Used IV or subcutaneously.
Can be used prophylactically to stop patients getting clots in the perioperative period.
Invasive dental procedures should be avoided during active treatment
Used infrequently compared with LMWH except in dialysis patients
Short t1/2 effects last a few hours
Procedures safe 12-24hrs after last administration
What are LMWH and give some example?
Low molecular weight heparins eg enoxaparin, dalteparin
What do LMWH do?
Inhibits activated factor X (Xa)
When are LMWH used and can you do dental procedures during treatment?
Used subcutaneously for prophylaxis of DVT and treatment of acute coronary syndromes and DVT/PE
Longer t1/2 - effects last upto 24hrs
Procedures safe with prophylactic doses
High (treatment) doses can usually be stopped for one day the day before surgery then resumed post-op following haemostasis.
What is warfarin and what does it do?
Vitamin K antagonist - inhibits vitamin K dependent clotting factors (2,7,9,10)
Increases clotting times (increases PT and INR)
What is the half life of warfarin?
3 days - so if stopped can still have prolonged clotting time for days after treatment
What is warfarin used for?
DVT/PE, atrial fibrillation, metallic heart valves etc
How is warfarin monitored?
INR (internationalised normalised ratio)
INR = prothrombin time / standard prothrombin time
What should the target INR’s be?
2.0-3.0 (average 2.5) for: treatment of DVT or PE, valvular heart disease, atrial fibrillation
3.0-4.0 (average 3.5) for: mechanical prosthetic heart valves
What does it mean if you have a higher INR?
The higher the INR, the more thinned the blood and the harder it is to clot.
What are the adverse effects of warfarin?
Bleeding (from anywhere!)
Skin rashes
Slope is
Diarrhoea, skin necrosis, jaundice
Bleeding peptic ulcer (from taking NSAIDs and warfarin eg)
Subconjuctival haemorrhage
Why can other drugs increase warfarin activity?
Inhibition of enzymes, CYP450, involved in its metabolism. So decreases platelet action.
Why can other drugs decrease warfarin activity?
Induction of enzymes involved in its metabolism. Reduced absorption.
What drugs interact with warfarin?
Analgesics: aspirin (AVOID high dose esp), NSAIDs (increase risk of GI bleed especially diclofenac). (Opioids and paracetamol are fine)
Antibiotics - inhibit metabolism
Which antibiotics increase the anticoagulant effect of warfarin?
Metronidozole
Macrolides (eg clarithromycin)
Quinolones (eg ciprofloxacin)
What should you do for patients on short-term warfarin/Anticoagulation therapy?
Delay procedure until Anticoagulation treatment completed
What should you do for patients on long-term warfarin/Anticoagulation therapy?
Consult patients physician
Check INR 72hrs prior to procedure (or within 24hrs if INR recently unstable)
This allows dose modification prior to procedure if INR > 4.0
Plant treat,ent for early in the day and week
What INR can you do non-invasive procedures for eg scale and polish?
Don’t need to check the INR prior
What should the INR be before doing invasive procedures (eg extractions, RCT)?
If INR <4.0, no need to alter dose, continue with procedure
If INR >4.0, adjust dose and recheck INR prior to treatment
How do you manage post-op bleeding?
Pressure, pack and suture
When should you seek advice from the patients Anticoagulation clinician?
If the INR is unstable or >4.0
The patient has thrombocytopenia, haemophilia or other disorders of haemostasis, or suffers from liver impairment, alcoholism, or renal failure
Patient is receiving Antiplatelet drugs, cytotoxic drugs or radiotherapy
What would you do in the even of urgent reversal of warfarin in bleeding (high INR)?
Administer vitamin K - 5mg IV for major bleed, 1-3mg IV for minor bleed
Fresh frozen plasma (FFP)
Extreme cases - clotting factor replacements (eg dried prothrombin complex)
What new anticoagulants are very widely used, what do they do and what are they used for?
Rivaroxaban, apixaban, edoxaban
Factor Xa inhibitors
For the treatment of DVT/PE
Risk of major bleeding is higher than with LMWH
Is coagulation monitoring required for NOACs? What are the guidelines?
Coagulation monitoring is not required for NOACs and reliable tests are not available
No evidence based guidelines for the dental management of patients receiving these agents
What is the guidance on stopping NOACs for dental treatment?
Most dental interventions can be safely performed without the alteration of Antiplatelet therapy or anticoagulant therapy in patients taking direct oral anticoagulants or vitamin K antagonists
Before high bleeding risk procedures, missing one dose of direct oral anticoagulants on the morning of the intervention may be recommended
PG488 READ ABOUT DIABETES
Know most of it but worth having a read as a refresher
What are the side effects of insulin treatment?
Hypoglycaemia
Risk depends on how low levels go and for how long
More likely in type 1, in renal failure, decreased oral intake, during exercise, after weight loss
Symptoms of type II diabetes
Thirst, polyuria, increased infection risk, lethargy
What is the most common oral anti diabetic agent to treat type II DM?
Sulfonyureas (eg gliclazide) and metformin commonly used
What complications can come (relevant to dent) from hyperglycaemia?
Increased risk of infection, but infection itself can also worsen diabetic control/blood sugars
Poor healing
DKA
Symptoms of hypoglycaemia
Sudden onset, due to excess insulin or minimum food intake
Sweaty, clammy, light headed
Hunger
May look as though ‘drunk’
Tremors, seizures
If prolonged and not treated, coma and even death
How should you manage diabetic patients?
Usually morning appointments - short
Prepare for emergencies - glucose supplement, snack
Alter insulin dosage for infections (increase dose)
Optimise blood sugar control prior to surgical procedures
Ensure adequate dietary intake after surgery
Medical consultation if necessary
If major procedure/requiring GA, pt will be nil by mouth so if insulin dependent DM (IDDM), may require admission the day before to control blood sugar with intravenous insulin
What is the endocrine system axis? - PG481 FOR FEEDBACK LOOP
HPA - hypothalamus, pituitary, adrenal glands, steroid hormone production
What do mineralocorticoids do?
Increase sodium and water retention - maintains BP
What do glucocorticoids do?
Involved with carbohydrate, lipid and protein metabolism
Cortisol has pleotrophic effects - affects transcription and translation of lots of different mediators
Inflammatory and immunosuppressive activity
Increases blood glucose, fight or flight response
What common corticosteroids are there?
Dexamethasone
Methylprednisolone
Prednisolone
Cortisone
Hydrocortisone (cortisol)
(last 2 also have significant mineralocorticoid activity)
How are corticosteroids used in dental practice?
Topical corticosteroids therapy for some forms of oral ulceration
What is indicated for long term steroid Tx?
Asthma/COPD
Inflammatory arthritis eg rheumatoid
Connective tissue disorders
Inmunosuppression
What are the side effects of steroid therapy?
(symptoms of Cushing’s)
Poor wound healing
Increased risk of infections including TB
Hypertension
Thin skin/easy bruising
DM (or hyperglycaemia)
Osteoporosis
Peptic ulcers
Abrupt withdrawal - adrenal crisis
Why does adrenal crisis occur from abrupt steroid withdrawal?
Exogenous steroids mean we switch off the negative feedback loop from the hypothalamus. So if we suddenly stop, we abruptly stop with no response from the hypothalamus and pituitary to make new steroids. Adrenal gland atrophy also.
What colour is the steroid emergency card?
Blue
What is adrenal (addisonian) crisis?
Provoke adrenal insufficiency after the use of exogenous corticosteroids
What are the main and other symptoms of adrenal crisis?
Main: Nausea, vomiting, fever, dehydration, weakness, hypoglycaemia, hyperkalaemia
Others: abdominal pain, confusion, hypotension, loss of consciousness, hypovolaemic shock, coma, death
What is the immediate treatment for adrenal crisis?
Lay patient flat
Give oxygen
Transfer to hospital
If facilities available: IV hydrocortisone 100mg stat, IV fluids rescucitation
What is the management of dental patients on long term steroids for minor dental procedures (with decreased LA)?
Rarely need additional steroid is on steroids currently
Some patients may be more sensitive - vigilance required
What is the management of dental patients on long term steroids for surgical oral treatment, severe post-op pain, stress?
Take usual daily dose
Double dose one hour prior to surgery and continue doubled dose for first post-op day
(To prevent relative insufficiency from stress)
How should you administer steroids if the patients are nil by mouth?
Managed in secondary care
Intramuscular or IV hydrocortisone pre-op
Double oral dose of corticosteroids for 24hrs post-op
