Yes, you can safely take Eliquis 3 hours after taking Synthroid
There is no known drug interaction between apixaban (Eliquis) and levothyroxine (Synthroid), and taking them 3 hours apart is more than adequate to avoid any potential absorption issues with levothyroxine.
Key Evidence
The available evidence demonstrates no clinically significant interaction between these medications:
No documented interaction exists: Extensive drug interaction guidelines for both apixaban 1 and levothyroxine 2 do not identify any interaction between these two medications. Apixaban interacts primarily with CYP3A4 and P-glycoprotein inhibitors/inducers 3, while levothyroxine absorption is affected by substances that bind it in the gastrointestinal tract or alter its metabolism 2.
Different mechanisms: Apixaban is a direct Factor Xa inhibitor that does not affect thyroid hormone absorption or metabolism 3. Levothyroxine absorption concerns relate to substances like calcium, iron, proton pump inhibitors, and bile acid sequestrants that physically bind the hormone 4, 5—not anticoagulants.
Optimal Timing Considerations
While 3 hours is sufficient, here's what you should know about timing:
For Synthroid (levothyroxine):
- Should be taken consistently 30-60 minutes before breakfast on an empty stomach with water 2
- Alternatively, can be taken at bedtime, 4 hours after the last meal 2
- The goal is to maximize absorption, which occurs best on an empty stomach
For Eliquis (apixaban):
- Can be taken with or without food 3
- Should be taken twice daily at approximately 12-hour intervals
- No specific timing restrictions relative to other medications (except those that are combined P-gp and strong CYP3A4 inhibitors) 3
Practical Recommendations
Your specific regimen of taking Eliquis 3 hours after Synthroid is perfectly safe and appropriate. Here's a suggested approach:
- Take Synthroid first thing in the morning on an empty stomach with water
- Wait at least 30-60 minutes before eating breakfast
- Take Eliquis 3 hours later (or at any convenient time)—this timing poses no risk
Important Caveats
While these medications don't interact with each other, be aware of:
Substances that DO affect Synthroid absorption 2, 5:
- Iron supplements (separate by 4 hours)
- Calcium supplements (separate by 4 hours)
- Proton pump inhibitors
- Bile acid sequestrants (separate by 4-6 hours) 4
Medications that DO affect Eliquis 1, 3:
- Combined P-gp and strong CYP3A4 inhibitors (ketoconazole, itraconazole, ritonavir) require dose reduction
- Strong CYP3A4 inducers (rifampin) should be avoided
- The 3-hour separation from Synthroid is irrelevant to these interactions
Bleeding risk monitoring: While unrelated to the Synthroid interaction, patients on Eliquis should be monitored for signs of bleeding 3. This is a property of the anticoagulant itself, not an interaction effect.
The one case report of spuriously elevated thyroid function tests in a patient on apixaban 6 was due to fibrin interference with the laboratory assay itself—not a true drug interaction—and would not be prevented by timing separation.