Drug Detail:Apixaban (Apixaban [ a-pix-a-ban ])
Drug Class: Factor Xa inhibitors
1. How it works
- Apixaban may be given to reduce the risk of blood clot formation.
- Apixaban works by selectively inhibiting (blocking) the effects of factor Xa (FXa), an enzyme that plays a key role in the formation of substances that cause blood clotting. Through its action on FXa, apixaban makes blood less likely to clot.
- Apixaban belongs to the class of drugs known as factor Xa inhibitors. It may also be called an anticoagulant.
2. Upsides
- Used to reduce the risk of stroke and blood clot formation in people with nonvalvular Atrial Fibrillation (AF).
- Also used to protect against the development of deep vein thrombosis (DVT) (blood clots in the deep veins) following hip or knee replacement surgery.
- Apixaban is also used in the treatment of DVT and pulmonary embolism (PE) (where blood clots lodge in the lungs), and to lower the risk of recurrent DVT and PE.
- Does not require regular blood tests.
- An antidote was approved in 2018, called andexanet alfa. However, the actual risk of major bleeding is low.
- Apixaban is available as an oral tablet in two strengths (2.5mg and 5mg).
- Dosing is straightforward. The recommended dosage for most people is 5mg twice a day. For people with at least two of the following: aged at least 80 years, body weight 60kg or lower, serum creatinine at least 1.5 mg/dL, then the dosage is 2.5mg twice daily.
- When given to prevent DVTs from forming after hip or knee replacement surgery the dosage is 2.5mg twice a day starting 12 to 24 hours after surgery.
- A suspension may be made from the tablets for people who cannot swallow tablets whole. Crush one 2.5mg or 5mg tablet (depending on the dosage) and suspend in water, 5% dextrose in water, or apple juice, or mix with apple sauce and administer within four hours.
- Less likely than warfarin to interact with other drugs or foods; however, it does interact with some medicines.
- Apixaban is available as a generic.
3. Downsides
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- Minor bleeding, nausea, anemia, and hemorrhage are the most common side effects. Gastrointestinal side effects such as constipation, vomiting, diarrhea, or abdominal pain may also occur.
- Severe bleeding is uncommon; however, the risk is increased in people with kidney disease or taking other medications that also reduce the ability of the blood to clot.
- Consider coverage with another anticoagulant if apixaban needs to be stopped for any reason other than significant bleeding or completion of the course of therapy because premature discontinuation has been associated with thrombotic events (the formation of a blood clot within a blood vessel).
- There is an increased risk of spinal or epidural hematomas resulting in long-term or permanent paralysis forming in people taking apixaban who are also undergoing spinal puncture or epidural or spinal anesthesia. The risk is greater in those taking other medications that affect blood clotting (such as NSAIDs, aspirin), with a history of traumatic or repeated spinal procedures or a history of spinal deformity or surgery.
- May not be suitable for some people including those with artificial heart valves, undergoing epidural or spinal anesthesia or spinal puncture, or with active bleeding.
- May be difficult to confirm if the "one dosage fits all" regimen suits everybody, because there is not a commercial blood test available to check the actual effect apixaban is having on each individual taking it.
- Guidelines suggest avoiding the use of apixaban in people who are obese (BMI >40kg/m2 or weight of 120kg or more) because there is a lack of research investigating the use of the drug in this population.
- May interact with several other drugs including other anticoagulants and NSAIDs, drugs metabolized through CYP 3A4, hormonal agents, St John's Wort, and omega 3 fatty acids.
Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects
4. Tips
- May be taken with or without food.
- Tablets may be crushed and mixed with water or apple juice/sauce to make swallowing easier. Swallow mixture straight away and do not save for later use.
- Apixaban is usually dosed twice daily. Check with your doctor what dosage is recommended for you. Take exactly as directed. If you miss a dose, take the dose as soon as you remember but if it is almost time for your next dose, do not double up the dose to make up for the missed dose. Just go back to your usual twice-daily dosage schedule.
- Tell all healthcare providers that you are taking Apixaban. Apixaban may need to be temporarily discontinued at least 48 hours before surgery that carries a moderate-to-high risk of unacceptable or clinically significant bleeding; 24 hours before surgery with a low risk of bleeding or if bleeding likely to be noncritical. Bridging therapy is not usually required and apixaban should be re-started once the risk of bleeding post-surgery has returned to normal.
- Apixaban may also increase your risk of bleeding from a minor fall or bump on the head. Contact your doctor if you experience an injury or have bleeding that will not stop. Call 911 if you experience severe or unstoppable bleeding, pink or brown urine, red or black tar-like stools, coughing or vomiting up blood or blood clots (may look like coffee grounds). Also seek urgent medical help with any symptoms of a stroke (such as sudden dizziness, headache or loss of vision; difficulty with speech or slurring of your words, one-sided facial drooping) or signs of a blood clot (sudden, severe shortness of breath; pain, heat or swelling in a limb).
- Your doctor may require you to undertake extra monitoring when switching to or from apixaban.
- Do not stop taking apixaban suddenly. Your doctor will advise you on how to discontinue apixaban when or if you no longer require it.
- Talk to your doctor or pharmacist before taking any other medication with apixaban, including that bought over-the-counter to check that it is compatible.
5. Response and effectiveness
- Peak concentrations of apixaban appear within 3 to 4 hours of an oral dose. Absorption is not affected by food or by crushing the tablets but the rate of absorption is reduced at higher dosages.
- Effect on blood clotting factors happens within a few hours of taking a single dose of apixaban. When apixaban is stopped, its effect on clotting begins to wear off within 24 hours.
6. Interactions
Medicines that interact with apixaban may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with apixaban. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.
Common medications that may interact with apixaban include:
- amiodarone
- antibiotics, such as erythromycin,
- anticonvulsants such as carbamazepine, phenobarbital, phenytoin or valproic acid
- antimicrobial agents, such as ciprofloxacin, clarithromycin, erythromycin, metronidazole
- antivirals, such as boceprevir, or delavirdine
- aspirin
- cancer medications, such as zanubrutinib
- cyclosporine
- dabigatran
- dextran
- echinacea
- garlic
- ginseng
- heparin
- HIV medications such as saquinavir
- medications that inhibit or induce CYP3A4 enzymes, such as fluconazole, ketoconazole, or ritonavir
- methotrexate
- mifepristone
- NSAIDs, such as ibuprofen, celecoxib, diclofenac, etodolac, and naproxen
- rifampin
- St John's Wort
- tinzaparin
- warfarin.
In general, any medicine that can increase the risk of bleeding (such as abciximab, clopidogrel, SSRI antidepressants [eg, citalopram, duloxetine, fluoxetine, venlafaxine], fish oils) may interact with apixaban.
Alcohol may increase the risk of stomach bleeding with apixaban.
Note that this list is not all-inclusive and includes only common medications that may interact with apixaban. You should refer to the prescribing information for apixaban for a complete list of interactions.