What apixaban does
Forming a blood clot is a chain of steps, and apixaban interrupts one specific step by blocking Factor Xa, a protein that the body needs to make thrombin. Less thrombin means less fibrin, and less fibrin means clots are less likely to form. The effect is predictable, comes on within a few hours of a dose, and wears off within roughly 12 hours after the last dose.
We call apixaban a DOAC (direct oral anticoagulant) — sometimes also written NOAC. It belongs to the same family as rivaroxaban, dabigatran, and edoxaban, but each has its own dosing schedule and clearance pattern.
Apixaban is sold in the United States as Eliquis (apixaban) by Bristol-Myers Squibb and Pfizer.
Who we prescribe it for
The two situations we use it most often are:
- Stroke prevention in atrial fibrillation. When we calculate your stroke risk (using a score called CHA₂DS₂-VASc) and the risk is meaningful, the benefit of being on a blood thinner outweighs the bleeding risk.
- Treatment and prevention of venous clots — deep vein thrombosis (DVT) in the leg and pulmonary embolism (PE) in the lungs.
We also use it after certain orthopedic surgeries and in some patients with mechanical clots in the heart, though those are more specialized situations.
We do not use apixaban for patients with mechanical heart valves or for moderate-to-severe mitral stenosis from rheumatic heart disease — warfarin is required in those cases.
How to take it
Twice a day, roughly twelve hours apart. With or without food — it doesn’t matter. The standard dose is 5 mg twice daily. We reduce to 2.5 mg twice daily when at least two of these three apply: age 80 or older, weight 60 kg (132 lb) or less, or creatinine 1.5 mg/dL or higher. For DVT or PE treatment, the starting dose is higher for the first week.
If you miss a dose, take it as soon as you remember in the same day. If it’s already close to the next dose, skip the missed one — never double up.
Side effects to watch for
The main side effect is bleeding. Most bleeding is minor: easier bruising, a bit more bleeding from a cut, a nosebleed that takes longer to stop. Things we want to know about right away:
- Black, tarry stools or bright red blood from the rectum.
- Vomiting blood or material that looks like coffee grounds.
- A severe headache that comes on suddenly, or any new neurologic symptom (weakness, numbness, difficulty speaking).
- Pink, red, or brown urine.
- A fall with a head injury — even if you feel fine.
Some patients also notice mild GI upset. Allergic reactions are uncommon but possible.
Drug and food interactions
Apixaban is processed by enzymes (CYP3A4 and P-glycoprotein), and a handful of medications can either raise or lower the level in the blood:
- Raise apixaban levels (more bleeding risk): ketoconazole, itraconazole, ritonavir, clarithromycin.
- Lower apixaban levels (less protection): rifampin, phenytoin, carbamazepine, St. John’s wort.
Combining apixaban with aspirin, NSAIDs (ibuprofen, naproxen), or other anticoagulants meaningfully increases bleeding — we discuss whether that combination is actually needed. Always tell your dentist, surgeon, or other prescribers that you are on a blood thinner.
There are no specific dietary restrictions — unlike warfarin, leafy greens don’t matter.
Around procedures
For most procedures we hold apixaban for 48 hours beforehand (longer if kidney function is reduced). For minor dental work, we often don’t stop it at all. We’ll always give specific instructions ahead of any planned procedure.
Reversal in an emergency
For life-threatening bleeding or an emergency procedure, andexanet alfa is a specific reversal agent that binds and inactivates apixaban. It is available in most hospitals. Four-factor prothrombin complex concentrate (4F-PCC) is an alternative we use in some settings. For minor bleeding, simply holding the next few doses is usually enough — apixaban wears off relatively quickly.
When to check in with us
Call us if you have bleeding that won’t stop, a fall with head injury, kidney function changes, or before any procedure. We typically check kidney function at least once a year while you are on apixaban.
Manufacturer reference
For official prescribing information, indications, and the latest information on Eliquis (apixaban) from Bristol-Myers Squibb / Pfizer, see the manufacturer’s site: eliquis.com. (External link — content there is the manufacturer’s and may include promotional material.)