Drug Interactions with Apixaban (Eliquis)
None of the medications listed - atorvastatin, metoprolol, levothyroxine, CoQ10, or Miralax - significantly affect the anticoagulant intensity of apixaban (Eliquis).
Mechanism of Apixaban Metabolism and Potential Interactions
Apixaban is primarily metabolized via the liver through CYP3A4 pathways and is a substrate for P-glycoprotein transport proteins. According to clinical guidelines, only drugs that act as strong inhibitors of both CYP3A4 and P-glycoprotein have been shown to cause important reductions in clearance of direct oral anticoagulants like apixaban, resulting in significant increases in plasma concentrations 1.
Atorvastatin
- Studies specifically examining atorvastatin with rivaroxaban (another direct factor Xa inhibitor similar to apixaban) found that "the concomitant administration of rivaroxaban with substrates of either CYP3A4 or P-glycoprotein, such as atorvastatin, digoxin, or midazolam, did not result in clinically relevant interactions" 1.
- While atorvastatin is metabolized by CYP3A4, it is not considered a strong inhibitor of this enzyme or P-glycoprotein.
Metoprolol
- Recent research has compared metoprolol with diltiazem (a known CYP3A4 inhibitor) in patients taking apixaban. The study found that diltiazem increased bleeding risk compared to metoprolol, suggesting that metoprolol does not significantly affect apixaban metabolism 2.
- This 2024 study provides the most recent evidence that metoprolol is a safe choice for rate control in patients taking apixaban.
Levothyroxine
- There is no evidence in the provided guidelines or research that levothyroxine interacts with apixaban.
- Levothyroxine has a different metabolic pathway and is not known to affect CYP3A4 or P-glycoprotein.
Coenzyme Q10 (CoQ10)
- No evidence suggests that CoQ10 supplementation affects apixaban metabolism or anticoagulant effect.
- While CoQ10 levels can be affected by medications like atorvastatin 3, 4, there is no indication that CoQ10 itself impacts anticoagulant intensity.
Miralax (Polyethylene Glycol)
- Polyethylene glycol is not absorbed systemically to any significant degree.
- There is no evidence in the provided literature that Miralax interacts with apixaban metabolism or effectiveness.
Drugs That Do Affect Apixaban
For context, medications that do significantly interact with apixaban include:
- Strong dual inhibitors of CYP3A4 and P-glycoprotein:
- Azole antifungals (ketoconazole, itraconazole, voriconazole, posaconazole)
- HIV protease inhibitors
- Strong CYP3A4 inducers (rifampin, phenytoin, carbamazepine, phenobarbital, St. John's wort)
Monitoring Considerations
While routine coagulation monitoring is not required with apixaban, certain laboratory tests may be affected:
- PT/INR: May be mildly elevated but not reliably
- aPTT: Generally less sensitive to apixaban than to direct thrombin inhibitors 1
Clinical Implications
For patients taking apixaban with the medications in question:
- No dose adjustments of apixaban are necessary based on concomitant use of atorvastatin, metoprolol, levothyroxine, CoQ10, or Miralax.
- Standard dosing considerations for apixaban should be based on age, weight, and renal function rather than these concomitant medications.
- In elderly patients (>80 years), reduced dosing of apixaban (2.5 mg twice daily) may be warranted based on age and other factors, but not due to interactions with these specific medications 5.
The safety profile of apixaban remains favorable when used with these common medications, allowing clinicians to focus on other aspects of patient management without concerns about these specific drug interactions.