Anticoagulation Flashcards
Apixaban DOSES
For the prophylaxis of stroke and systemic embolism in adults with non-valvular atrial fibrillation and at least one risk factor, such as previous stroke or transient ischaemic attack, symptomatic heart failure, diabetes mellitus, hypertension, or age 75 years and over:
The recommended dose is __
When should the dose be reduced?
5mg OD
Dose should be reduced to 2.5 mg BD in people with:
1. At least 2 of the following characteristics:
- age 80 years or over,
- body weight 60 kg or less,
- serum creatinine 133 micromol/L or over.
2. Creatinine clearance (CrCl) 15–29 mL/minute.
Treatment is usually long term.
Apixaban DOSES
For the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE):
The recommended dose is _____
What should be minimum duration?
For the tx DVT PE: 10 mg BD for first 7 days, followed by 5 mg BD.
Duration <= transient risk factors (for example, recent surgery, trauma, and immobilization), but it should be for a MINIMUM of 3 months.
Apixaban DOSES
For the prophylaxis of Recurrent DVT and PE in adults (following completion of 6 months of anticoagulation treatment): __________
For the prophylaxis of venous thromboembolism (VTE) in people who have undergone hip replacement surgery: ___________
Prophylaxis of VTE in people who have undergone knee replacement surgery: __________
Prophylaxis recurrent DVT and PE in adults (after 6 months of anticoagulation treatment):
= 2.5 mg BD.
Prophylaxis VTE for hip replacement surgery:
= 2.5 mg BD for 32–38 days, started 12–24 hrs after surgery.
Prophylaxis of VTE for knee replacement surgery:
= 2.5 mg BD for 10–14 days, started 12–24 hrs after surgery.
What are the contraindications and cautions for apixaban?
- preg / breast feeding
- Creatinine clearance (CrCl) < 15 mL/minute.
- Liver disease; coagulopathy and bleeding risk.
- A prosthetic heart valve
- Antiphospholipid syndrome — ^ ! recurrent thrombotic events.
- Active bleeding.
- People with a significant risk of major bleeding
Apixaban - if spontaneous bleeding occurs and does not stop, or recurs
- sudden severe back pain
Seek immediate medical advice
back pain = retroperitoneal bleeding
This includes bruising, bleeding gums, nosebleeds, prolonged bleeding from cuts, blood in the urine or stools, haemoptysis, subconjunctival haemorrhage, and vaginal bleeding in a postmenopausal woman.
specific reversal agent indicated for adults treated with a direct factor Xa (FXa) inhibitor (apixaban or rivaroxaban) when reversal of anticoagulation is needed due to life-threatening or uncontrolled bleeding.
Andexanet alfa (Ondexxya®)
Other adverse effects of apixaban include:
Common —
Uncommon —
Other adverse effects of apixaban include:
Common — anaemia, bruising, nausea, and skin reactions.
Uncommon — angioedema, erythema multiforme, hypotension, post procedural haematoma, thrombocytopenia, and wound complications.
apixaban x nsaid
apixaban x anticoagulants / antiplatelets
bleeding risk
apixaban x strong CYP 450 and PGP inhibitors
Strong inhibitors of both cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp), such as itraconazole, ketoconazole, and HIV protease inhibitors (for example ritonavir) — plasma concentration of apixaban is increased by these drugs.
For drugs that are not considered strong inhibitors of both CYP3A4 and P-gp, such as amiodarone, clarithromycin, diltiazem, fluconazole, quinidine, and verapamil, the plasma concentration of apixaban is
For drugs that are not considered strong inhibitors of both CYP3A4 and P-gp, such as amiodarone, clarithromycin, diltiazem, fluconazole, quinidine, and verapamil, the plasma concentration of apixaban is increased to a lesser extent. No dose adjustment for apixaban is required with these drugs, but the person should be monitored for signs of bleeding or anaemia.
apixaban x Strong inducers of both CYP3A4 and P-gp, such as _
Strong inducers of both CYP3A4 and P-gp, such as carbamazepine, phenytoin, rifampicin, and St John’s Wort — plasma concentration of apixaban may be reduced by these drugs.
apixaban x ssri / snri / venlafaxine
SSRI (citalopram), SNRI (duloxetine), and venlafaxine — possible ^ risk of bleeding.
The manufacturer of apixaban advises to avoid.
If concurrent use is indicated, monitor for signs of bleeding and anaemia
Switching from warfarin to apixaban:
STOP warfarin, and measure INR:
INR < 2, start apixaban.
INR 2 - 2.5, start apixaban the next day.
INR > 2.5, wait until the person’s INR has dropped to less than 2 before starting apixaban.
Switching from apixaban to warfarin:
START warfarin, but do not stop apixaban.
- After at least 2 days with warfarin and apixaban, measure INR prior to next scheduled dose of apixaban.
=> INR in target range, stop Apix and continue warfarin.
=> INR not in target range, continue BOTH until INR is in the target range, then stop apixaban.
- Warfarin has a slow onset; 5–10 days before INR is within range.
After tx with apixaban has stopped:
Measure INR after 24 hours
Monitor INR closely (once a week) in the first month of warfarin tx until the person has THREE consecutive stable INR values (for example between 2–3).
Switching from apixaban to another direct-acting oral anticoagulant (DOAC):
STOP apixaban
START the new DOAC (dabigatran, edoxaban, or rivaroxaban) when the next dose of apixaban is due.
- If higher than therapeutic plasma conc. are expected, e.g impaired renal function, a longer interval in between DOACs is recommended.
Switching from another DOAC to apixaban:
STOP DOAC (dabigatran, edoxaban, or rivaroxaban), START apixaban when the next DOAC dose is due. - If higher than therapeutic plasma conc. are expected, e.g impaired renal function, a longer interval in between DOACs is recommended.
Should apixaban be stopped if surgery or dental treatment is required?
- surgery / invasive procedure
- minor surgical procedure with minor bleeding
- low bleeding risk
- high bleeding risk
May need to stop <= risk of thromboembolic event and bleeding risk.
- Minor surgery/risk (performed 12–24 hrs after last dose); do not to interrupt oral anticoagulation. Could practically have intervention scheduled 18–24 hrs after last dose of apixaban is taken, then restart apixaban 6 hours later. So one dose of apixaban may be missed.
- Low bleeding risk, apixaban should be stopped at least 24 hours before the procedure. If CrCl is 15–29 mL/minute, stop Apixaban 36 hrs before procedure.
- HIGH bleeding risk, stop 48 hrs before procedure.
INR monitoring in apixaban regimen
No need to monitor INR; however, regular follow up and monitoring is recommended.
Apixaban
- Start of apixaban tx tests
- monitoring
At the start of treatment
baseline clotting screen, RFT and LFT, FBC
Repeat the FBC, RFT, LFT yearly for most people.
Apixaban tx started review time
Once tx has started, review the person on a regular basis, preferably after 1 month initially and at least every 3 months thereafter. Follow-up intervals may be longer (up to every 6 months) or shorter (eg every month) depending on patient factors, such as renal function, age, and comorbidities.
Repeat the FBC, RFT, LFT yearly for most people on Apixaban but what if pt is:
- old and frail
- CrCl
- intercurrent illness that may impact renal/hepatic function
If the person is frail or > 75 years, repeat the blood tests every 6 months.
If the person has a creatinine clearance (CrCl) less than 60 mL/minute, the frequency of monitoring (in months) can be guided by the CrCl divided by 10. For example, every 3 months if CrCl is 30 mL/minute.
If the person has an intercurrent illness that may impact renal or hepatic function, repeat renal and liver function tests as needed.
If the person has missed a dose of apixaban
If the person has missed a dose of apixaban, the forgotten dose may be taken until half of the dosing interval has passed.
This means that the forgotten dose can be taken up until 6 hours after the scheduled intake. After this time point, the dose should be skipped and the next scheduled dose should be taken.
The 6-hour interval may be extended in people with a high stroke risk and low bleeding risk.
If the person has taken a double dose of apixaban
If the person has taken a double dose of apixaban, they should omit the next planned dose (that is, after 12 hours) and resume treatment as normal 24 hours after the double dose intake.
Dabigatran dose?
For the prophylaxis of stroke and systemic embolism in adults with non-valvular AF and with one or more risk factors, such as previous stroke or transient ischaemic attack, symptomatic heart failure, age 75 years or older, diabetes mellitus, or hypertension:
Duration?
150 mg twice a day. Reduced dose of 110–150 mg BD if: - Is aged 75–79 years. - Moderate renal impairment [CrCl] 30–50 mL/minute), - Is at increased risk of bleeding. Reduced dose of 110 mg BD if: - Is aged 80 years and older. - Concurrent treatment with verapamil.
Treatment is usually long term.
Dabigatran dose?
For the treatment of DVT and PE and the prevention of recurrent DVT and PE, following initial use of parenteral anticoagulation for at least 5 days:
Duration?
150 mg twice a day. Reduced dose of 110–150 mg BD if: - Is aged 75–79 years. - Moderate renal impairment [CrCl] 30–50 mL/minute), - Is at increased risk of bleeding. Reduced dose of 110 mg BD if: - Is aged 80 years and older. - Concurrent treatment with verapamil.
Duration <= risk:benefit for bleeding
- Short duration (at least 3 months) = transient risk factors (eg recent surgery, trauma, immobilization).
- Longer durations = permanent risk factors or idiopathic DVT or PE.
Dabigatran dose?
For the prevention of VTE in knee replacement surgery:
110 mg to be taken 1–4 hours after surgery, followed by 220 mg once daily for 10 days.
Reduced dose of 75 mg taken 1–4 hours after surgery, followed by 150 mg once daily for 10 days if:
- Is aged 75 years or older.
- Is receiving concurrent treatment with verapamil.
- Mod renal impairment (CrCl 30–50 mL/minute).