AF

Question 1

symptoms of AF?

Answer 1

Half notice palpitations
Dyspnoea (difficulty breathing)
Fatigue
Syncope 
Chest pain
50% are asymptomatic

Question 2

1st line treatment for permeant / persistent AF?

Answer 2

Beta-blocker (e.g. atenolol, bisoprolol)
OR
Rate controlling calcium channel blocker (verapamil, diltiazem)

If monotherapy does not work – two of either betablocker, diltiazem, digoxin

If rate cannot be controlled on dual therapy – control rhythm

Question 3

side effects of digoxin?

Answer 3

nausea & sickness, diarrhoea, dizziness, bradycardia, visual disturbance and confusion particularly when overdosed

Question 4

side effects of amiodorane?

Answer 4

In the long term a very “dirty drug”
Corneal micro deposits, Thyroid disease, pulmonary fibrosis & hepatotoxicity limit long term use
Photosensitivity and skin discolouration very common
Serious interaction with Digoxin & Warfarin

Question 5

monitoring of warfarin?

Answer 5

International Normalised Ratio (INR)
Test to see how long blood takes to clot
Normal INR is 1.0
Compares patient’s prothrombin time to lab standard (15 secs)
Target INR depends on indication for oral anticoagulation
In AF aim for Target of 2.5 (Range 2-3)

Question 6

side effects of warfarin?

Answer 6

1. Haemorrhage
2. Skin reactions (Necrosis v rarely)
3. Others including GI upset, LFT abnormality, hypersensitivity
4. Teratogenicity

Question 7

which drugs interact with warfarin?

Answer 7

• Reduced warfarin absorption
  (eg cholestyramine,laxatives)
• Increased warfarin metabolism
  (Hepatic Cytochrome P450)
  (eg barbiturates, rifampicin, carbamazepine)
• Herbal medicines
  eg St Johns Wort increases warfarin metabolism
• Reduced warfarin metabolism (Hepatic Cytochrome P450)
  eg metronidazole, cimetidine, amiodarone, erythromycin, ciprofloxacin, fluconazole, omeprazole, simvastatin, ETOH
  Less warfarin required
• Increased risk of bleeding
  eg aspirin,clopidogrel, NSAIDs
• Unknown mechanisms
  eg fluoxetine, corticosteroids
• Vitamin K Interference
  Broad spectrum antibiotics,Vitamin K foods