Quiz Summary
0 of 5 Questions completed
Questions:
Information
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading…
You must sign in or sign up to start the quiz.
You must first complete the following:
Results
Results
0 of 5 Questions answered correctly
Your time:
Time has elapsed
You have reached 0 of 0 point(s), (0)
Earned Point(s): 0 of 0, (0)
0 Essay(s) Pending (Possible Point(s): 0)
Average score |
|
Your score |
|
Categories
- Communication skills 0%
-
Gold standard case presentation
NOACs and vitamin K antagonists
Since the advent of the novel oral anticoagulants (NOACs) depending upon what your local policy is the NOACs have become the primary treatment choice for non-valvular atrial fibrillation (NVAF) and thromboembolic disease (pulmonary emobolism and/or deep vein thromboses). there is still a role for vitamin K antagonists (warfarin) in valvular AF as well as those who are intolerant or allergic to NOACs. If you would like more information with regards to the trials comparing NOACs to vitamin K antagonists here is a screencast lecture that you can watch. Otherwise here is a summary of the different options comparing NOACs and vitamin K antagonists. There has been a lot of debate and discussion with regards to the definitions of valvular and nonvalvular AF the European Society of Cardiology definition of non-valvular AF which is currently used as a counterpoint to non-valvular AF and non-valvular AF ‘is restricted to cases in which the rhythm disturbance occurs in the absence of rheumatic mitral valve disease, a prosthetic heart valve or mitral valve repair. Vitamin K antagonists are primarily warfarin however in Germany for example they use phenprocoumon – hence from now on we will talk about vitamin K antagonists (VKA). There are currently four NOACs on the market, dabigatran, rivaroxaban, edoxaban and apixaban. All the data that has been carried out with NOACs compares each of them separately with VKA. There are no head-to-head studies and there will likely never be head-to-head-studies and the trials are not easily comparable to help determine which is the best NOAC for which condition. The side effects of the NOACs are primarily indigestion and nausea, diarrhoea and loose stools and minor bleeding and/or bruising. Major bleeding does occur but on the whole with a reduced incidence compared to VKA. Apixaban has an advantage in reducing the rate of ischemic and hemorrhagic strokes compared to VKA. Dabigatran reduces the number of hemorrhagic strokes compared to VKA and the same for rivaroxaban. When comparing bleeding outcomes, there is a reduction in major bleeds with dabigatran and apixaban and rivaroxaban.
Key features in counselling for vitamin K antagonists
- compliance ensuring VKA tablet is taken at the same time everyday and to not double up doses
- ensure patients know where they can obtain a supply and holiday planning
- explain what the international normalisation ratio (INR) is and the process of regular monitoring and explain the side effects as explained above
- bleeding Symptoms
- severe bruising, tea-coloured urine, dark, tarry stools,
- coughing up blood (coffee-stained), severe headache, prolonged bleeding.
- Recurrence of thromboembolism
- new pain, shortness of breath, pain,
- swelling redness in an extremity, sudden inability to speak, slurred speech,
- sustained numbness or weakness in arm/leg
- bleeding Symptoms
- actions to take if bleeding or bruising occur
- how to manage if patient is vomiting or has diarrhoea
- loading versus maintenance dosing and changing doses compared to INR
- drug and food interactions
- over-the-counter medicines:
- Aspirin
- Ibuprofen
- ‘health’ Shop herbal remedies
- Ask pharmacist/GP for advice
- prescribed Medicines:
- importance of notifying changes
- starting/stopping interacting medicines
- foods high in Vitamin K
- importance of moderation with Vitamin K rich foods (green vegetable)
- diet should be well balanced
- over-the-counter medicines:
- moderation of alcohol intake – no more than two units a day
- contraception and pregnancy if appropriate
- surgical procedures including dental work
- avoid intramuscular injections
- avoid sports and activities which may result in serious fall or injury
Medications that interact with VKA:
Gastrointestinal
- Cimetidine
- omeprazole and possibly other PPIs
Cardiovascular
- amiodarone* (liver enzyme inhibition is slow and may persist long after withdrawal requiring weekly monitoring over 4 weeks),
- fibrates
- ezetimibe
- propafenone
- propranolol
- statins – no clinically relevant interaction will normally be seen however it is prudent to check INR in the weeks after initiation and at any dose change
CNS
- Fluvoxamine
- SNRIs
- SSRIs
- tramadol
Antibiotics
- co-trimoxazol
- macrolides (can be serious but unpredictable)
- metronidazole
- quinolones (can be serious but unpredictable)
- tetracyclines
- influenza vaccine
Endocrine
- anabolic steroids (and danazol)
- high dose corticosteroids,
- glucagon (high dose 50mg+ over 2 days)
- Flutamide
- levothyroxine
NSAIDs
- ibuprofen at lowest effective dose (+/-PPI) is probably safest if NSAID is required
- N.B. All NSAIDs can increase the risk of bleeds and should be avoided if possible
Antiplatelets – increased bleed risk Aspirin, clopidogrel and dipyridamole
Miscellaneous
- alcohol (acute)
- allopurinol
- benzbromarone
- colchicine
- disulfiram
- Fluorouracil,
- interferon
- paracetamol (prolonged use at high dose)
- sulfinpyrazone
- tamoxifen
- topical salicylates
- zafirlucast
- Anti-infectives (antiinfectives in general may cause raised INR’s) azole antifungals* (esp. miconazole including oral gel and vaginal)
Herbal preparations/Food supplements
- carnitine, chamomile, cranberry juice, curbicin, dong quai, fenugreek, fish oils, garlic, gingo biloba, glucosamine, grapefruit juice, lycium, mango, quilinggao
Drugs that decrease the INR
Miscellaneous
- alcohol (chronic)
- azathioprine
- barbiturates
- bosentan
- carbamazepine
- carbimazole
- griseofulvin
- mercaptopurine
- nevirapine
- OCP/HRT
- propylthiouracil
- raloxifene
- rifampicin (most potent inducer)
- trazodone
Herbal preparations
- avocado
- co-enzyme Q10
- green tea
- natto
- soya beans
- St Johns wort (avoid)
Binding agents
- colestyramine
- sucralfate
NICE criteria for commencing a NOAC for stroke prevention and non-valvular AF:
Dabigatran is an option if: Non-valvular AF and NICE TA 249 criteria are satisfied, i.e. one or more of the following risk Factors:
- Previous stroke, TIA or systemic embolism
- Left ventricular ejection fraction below 40%
- Symptomatic heart failure of New York Heart Association class 2 or above
- Age 75 years or older
- Age 65 years or older with one of the following: diabetes mellitus, coronary artery disease or hypertension
Rivaroxaban is an option if: Non valvular AF and NICE TA 256 criteria are satisfied, i.e. one or more risk factors such as:
- Congestive heart failure
- Hypertension
- Age 75 years or older
- Diabetes mellitus
- Prior stroke or TIA
Apixaban is an option if: Non valvular AF and NICE TA 275 criteria are satisfied, i.e. one or more risk factors such as:
- Prior stroke or TIA
- Age 75 years or older
- Hypertension
- Diabetes mellitus
- Symptomatic heart failure
Click here to continue
- 1
- 2
- 3
- 4
- 5
- Current
- Review / Skip
- Answered
- Correct
- Incorrect
-
Question 1 of 5
1. Question
1 point(s)Name four NOACs.
-
- ;
- ;
- ;
- .
CorrectIncorrect -
-
Question 2 of 5
2. Question
1 point(s)Head to head trials show some NOACs are superior to others in differing contexts. True or false?
CorrectIncorrect -
Question 3 of 5
3. Question
1 point(s)Which of the following are side effects of NOACs? Select all that apply.
CorrectIncorrect -
Question 4 of 5
4. Question
1 point(s)Select the drug class with the highest risk of major bleeding.
CorrectIncorrect -
Question 5 of 5
5. Question
1 point(s)Select the drug class with the highest number of drug interactions.
CorrectIncorrect