Competency Exam Flashcards
Dose of apixaban for AF stroke prevention?
> 30: 5mg BD
15-29: 2.5mg BD
To reduce to 2.5mg BD if at least 2 factors:
- Body weight <= 60kg
- SCr >= 133
- Age 80yo and above
What are the INR targets for Warfarin for the various conditions?
2-3 for everything, except mechanical mitral heart valve 2.5-3.5
Dose for dabigatran for AF stroke prevention?
> 30: 150mg BD
<30: dont use
To reduce to 110mg BD if:
- 80yo and above OR
- concurrently using verapamil
Dose for rivaroxaban for AF stroke prevention?
> 50: 20mg OD
30-50: 15mg OD
<30: dont use
Dose for apixaban for treatment of VTE?
10mg BD x 1 week, then 5mg BD
(no renal dosing adjustments)
Dose for dabigatran for treatment of VTE?
Can only use after at least 5 days of parenteral treatment.
> 30: 150mg BD
<30: dont use
To reduce to 110mg BD if :
- 80yo and above OR
- concurrently using verapamil
Dose for rivaroxaban for treatment of VTE?
> 30: 15mg BD x 3 weeks, then 20mg OD
<30: dont use
Dose for apixaban for VTE prophylaxis for pts who underwent knee/hip replacement surgery?
2.5mg BD (no renal dosing adjustments)
Dose for dabigatran for VTE prophylaxis?
> 50: 220mg OD
30-50: 150mg OD
<30: dont use
Dose for rivaroxaban for VTE prophylaxis?
> 30: 10mg OD
<30: dont use
Dose of enoxaparin for VTE treatment?
1mg/kg Q12H
If <30: 1mg/kg Q24H
Dose of enoxaparin for VTE prophylaxis?
40mg OD
If <30: 30mg OD
How to switch from enoxaparin to DOACs?
Clexane > Apixaban: start at next dose of clexane
Clexane > Riva / dabi: start within 2h prior to next dose of clexane
How to switch from clexane to warfarin?
For treatment of VTE: overlap warfarin with clexane until INR >= 2 and for at least 5 days
What are the monitoring parameters for the different anticoagulants?
- Warfarin: INR
- Unfractionated heparin: aPTT
- LMWH: Anti-Xa
When will you consider to give lower doses of warfarin?
- Age>70yo
- Weight < 50kg
- Elevated baseline INR or low platelet count
- Disease states with increased warfarin sensitivity
At maintenance phase, what is the warfarin titration guide?
10% change in dose > INR change by 1
How much can stopping warfarin for one day reduce the INR?
0.2-0.5
When do I review pt’s INR after making changes to their maintenance dose of warfarin?
2 weeks (to allow INR to stabilise and make further adjustments as necessary).
What is an example of a clinically significant drug interaction for DOACs?
Dabigatran: P-gp substrate
Rivaroxaban, Apixaban: CYP3A4 substrate, P-gp substrate
Carbamazepine induces P-gp and CYP3A4.
Induce P-gp > increase efflux
Induce CYP3A4 > increase metabolism
HENCE, reduced efficacy of DOAC.
Category X interaction for all three DOACs.
Dose of unfractionated heparin for treatment of VTE?
80units/kg IV bolus > 18u/kg/h continuous IV infusion
(no renal adjustments needed)
Target aPTT for unfractionated heparin?
1.5-2.5x the control value
Metabolism of warfarin?
Substrate of CYP1A2 (minor), CYP2C19 (minor), CYP2C9 (major), CYP3A4 (minor);
What CYP interactions are there for St Johns Wort?
CYP inducer
Common factors that can affect the INR?
- Acute alcohol increases INR, chronic alcohol decreases INR
- hyperthyroid increases INR, hypothyroid decreases INR
- vit K rich foods decrease INR
- 3 Gs (garlic, gingko, ginger) increases bleeding risk (increase INR)
- Ginseng decreases INR
When is bridging anticoagulation indicated?
Pt is at high risk of thromboembolism (eg, atrial fibrillation with a high stroke risk score or recent stroke or transient ischemic attack, venous thromboembolism within 3 months, history of thromboembolism during interruption in therapy) /
Mechanical heart valve
How to bridge using Clexane?
- Stop warfarin ~5 days before procedure (assuming that target INR is 2-3 and pt INR is within range)
- SUBQ: 1 mg/kg every 12 hours; a reduced dose of 40 mg every 12 hours may be considered when bleeding is a concern; start enoxaparin ~3 days prior to the procedure when INR is subtherapeutic; the last dose of enoxaparin is administered ~24 hours before the planned procedure. Enoxaparin may be resumed ≥24 hours after procedures with low bleeding risk and ≥48 to 72 hours after procedures with high bleeding risk. Continue enoxaparin until warfarin has been resumed and INR is therapeutic
Starting dose and target dose of Entresto for HFrEF?
Starting dose: 50-100mg BD
Target dose: 200mg BD
(double dose after 1-2 weeks)
Starting dose and target dose of carvedilol for HFrEF?
Starting dose: 3.125mg BD
Target dose: if <=85kg: 25mg BD; >85kg: 50mg BD
(double every 2 weeks)
Starting dose and target dose of bisoprolol for HFrEF?
Starting dose: 1.25mg OD
Target dose: 10mg OD
(double every 2 weeks)
Starting dose and target dose of spironolactone for HFrEF?
Starting dose: 12.5-25mg OD
Target dose: 25-50mg OD
(double every 4 weeks)
Starting dose and target dose of eplerenone for HFrEF?
Starting dose: 25mg OD
Target dose: 50mg OD
(Double every 4 weeks)
Starting dose/target dose of dapa for HFrEF?
10mg OD
Starting dose/target dose of empa for HFrEF?
10mg OD
What is baclofen used for?
It is a skeletal muscle relaxant.
- Hiccups (off-label)
- Muscle spasm or musculoskeletal pain
- Spasticity
What medication should be spaced apart from enteral feeding?
Phenytoin (decrease phenytoin absorption). Space 1-2h apart.
What vitamins are good for pressure injury?
Vitamin C and Zinc
What medication is a/w SIADH?
All antidepressants, mostly SSRIs, possibly lower risk with agomelatine, mirtazapine, bupropion.
> > > Monitor serum Na
What makes up the allergy triad?
Asthma, allergic rhinitis, atopic dermatitis (eczema)
How to classify allergic rhinitis?
Intermittent: < 4 days a week OR < 4 consecutive weeks
vs
Persistent: >= 4 days a week AND 4 consecutive weeks
Mild: Normal sleep, no impairment of activities, AND no troublesome sx
Moderate-severe: Disturbed sleep, impairment of daily activities, OR having troublesome sx
What is the treatment for mild, intermittent allergic rhinitis?
Second gen oral antihistamine, administered regularly or as needed
What is the treatment for moderate-severe intermittent or mild persistent allergic rhinitis?
Intranasal corticosteroid nasal spray (takes time to work, can add on oral second gen antihistamine)
Which steroid nasal sprays are POM with exemption?
Nasacort (triamcinolone acetate), Nasonex (mometasone furoate), Avamys (Fluticasone furoate)
Max supply: 3 months, min age 18yo, max daily dose is 2 sprays into each nostril OD
(Flixonase is P only - fluticasone propionate)
PIL says indicated for only adults > 18yo.
Dose: 2 sprays into each nostril OD (max 2 sprays into each nostril BD)
How long does INC take to work?
Onset can be seen in a few hours, but peak benefits may require several days to weeks. Typically takes 3-7 days for sx relief to occur»_space; must continuously use it in first week of treatment.
When to discard intranasal corticosteroids?
Discard 2 months after opening for Nasacort and Avamys.
What are the strengths of topical decongestants for oxymetazoline?
Adults and children > 6yo: 0.05% Q8-12H
1-6yo: 0.025% Q8-12H
4 weeks - 1yo: 0.01% Q8-12H
(GSL item)
Do not use > 5 days to prevent rebound congestion.
Non-pharmacologcial advice for allergic rhinitis?
In allergic rhinitis, avoidance of potential allergens is important regardless of
medication taken 60
a. Animal dander
i. Remove the pet from the house, or from the bedroom
ii. Install HEPA filter and use air filters
b. Dust mites
i. Clean beddings and furniture covers in warm water with detergent, or use
dryer on hot setting
ii. Lower indoor humidity to <50%, by using low settings on humidifier
c. Cockroaches
i. Clean the house regularly, and empty the garbage daily
ii. In cases of severe infestations, seek professional exterminator
d. Indoor mould
i. Clean surfaces with dilute bleach solution
ii. Fix water leakages
What electrolytes predispose to AF?
Low K and low Mg; High Ca
Pharmacological agents for rate control in AF?
- If no comorbidities / hypertension / HFpEF:
first line: beta blocker or NDCCB - HFrEF:
first line: beta blocker - Severe COPD or asthma:
first line: NDCCB
2nd line agents:
digoxin (reduce HR), amiodarone
Lenient HR target of <110
Which beta blockers are cardioselective for B-1 receptors in the heart?
Atenolol, betaxolol, bisoprolol, metoprolol, nebivolol
What are common agents used for rhythm control in AF?
Amiodarone, sotalol
Does hyperthyroidism increase the risk for AF?
Yes
When to use what agent for rhythm control in AF?
If none or minimal signs of structural heart disease -> can use everything
CAD, HFpEF, significant valvular disease -> amiodarone, sotalol
HFrEF -> amiodarone
What is the CHA2DS2 VASc score?
C - congestive heart failure
H - hypertension
A2- age 75yo and above -> 2
65-74 -> 1
D - diabetes
S2 - stroke / TIA / thromboembolism
V - vascular disease (CAD / prev MI / PAD / aortic plaque)
A - age
Sc- female is 2, male is 1
Factors in HAS-BLED?
Hypertension > 160
Abnormal liver / kidney
Stroke
Bleeding tendency
Labile INR
Elderly >65yo
Drug / alcohol
If HASBLED >=3 -> higher bleeding tendency
How to manage over anticoagulation of warfarin?
If INR 4-5: withhold warfarin and check INR after 24h
5-9: omit next 1-2 doses and check INR after 24h. OR give Vit K PO 1-3mg
> 9: Omit warfarin and give vit K PO 3-5mg
Recheck INR after 6h then daily for 3 days
Anticoagulation for stroke prevention in AF?
If prosthetic mechanical heart valves or moderate-severe mitral stenosis > use warfarin.
CHADVASC 0 in men or 1 in women: don’t need
CHADVASC 1 in men or 2 in women: if factor is age 65-74, then treat.
CHADVASC 2 in men or 3 in women and above: treat.
What to take note for beta blockers?
- Impaired glucose control in diabetes (a/w new onset diabetes)
- Masks sx of hypoglycaemia (tremor, irritability, palpitations) > only sweating is unaffected