How long do you have to wait between blood thinners? A comprehensive guide

October 13, 2025 •

3 min read

According to the Red Cross, individuals on prescription blood thinners like warfarin must wait 7 days after stopping their treatment before donating blood, while those on DOACs like Eliquis must wait only 2 days. This disparity highlights a crucial point: the waiting period when switching or interrupting treatment varies significantly depending on the specific medication, underscoring why it is essential to know how long do you have to wait between blood thinners.

Quick Summary

The waiting time between blood thinners varies based on the specific medications involved, the reason for the change, and the patient's overall health. Switching DOACs is quick, while transitioning to or from warfarin requires careful overlap and monitoring. Stopping for procedures also has strict guidelines based on bleeding risk and medication half-life. All transitions demand close medical supervision.

Key Points

DOAC to DOAC: Switching between direct oral anticoagulants is typically a straightforward 'take the new one when the old one is due' process due to their rapid onset and offset of action.
Warfarin to DOAC: When switching from warfarin, you must wait for the INR (International Normalized Ratio) to drop below a specific target before starting the DOAC, which can take several days.
Heparin/LMWH to Warfarin: An overlap or 'bridging' period is required where both heparin and warfarin are taken concurrently until the INR reaches the therapeutic range, ensuring continuous protection.
Surgery and Procedures: Stopping blood thinners for surgery requires a specific waiting period, which varies by medication and bleeding risk, as directed by a healthcare provider.
Timing After Stroke: After an ischemic stroke, the waiting time to restart anticoagulation depends on the stroke's severity, ranging from 1 day for a TIA to up to 14 days for a severe stroke.
Professional Guidance is Essential: All transitions and interruptions of blood thinners must be supervised by a healthcare professional to ensure safety and prevent gaps in anticoagulation or excessive bleeding risk.

Why Timing is Critical When Switching Medications

Different anticoagulants work in various ways and have different half-lives, which impacts how quickly they take effect and leave the body. For example, warfarin's slow action necessitates an overlap with another anticoagulant during a transition. Direct Oral Anticoagulants (DOACs) act faster and have shorter half-lives, allowing for simpler switches. Incorrect transition protocols can lead to either inadequate clot prevention or increased bleeding risk.

Switching Between Direct Oral Anticoagulants (DOACs)

Switching from one DOAC to another is typically a direct swap. Stop the current DOAC and start the new one at the time the next dose of the old medication was due. Be sure to follow your doctor's instructions, especially regarding differing dose frequencies.

Transitioning from Warfarin to a DOAC

When switching from warfarin to a DOAC, the timing depends on your International Normalized Ratio (INR). Stop warfarin and begin the DOAC once your INR falls below a specific target (below 2.0 for dabigatran or apixaban; 2.5 or lower for rivaroxaban or edoxaban). If INR testing isn't readily available, your doctor may recommend waiting 2-3 days after the last warfarin dose.

Transitioning from a DOAC to Warfarin

Switching from a DOAC to warfarin requires an overlap period because warfarin works slowly. Often, a parenteral anticoagulant like LMWH is used for bridging alongside warfarin initiation. Start warfarin while continuing the DOAC for at least 2 days until your INR is in the therapeutic range (typically 2.0-3.0). Continue the DOAC until the INR is therapeutic. INR testing during this overlap should ideally be done just before the next DOAC dose.

Transitioning from Heparin/LMWH to Warfarin

This transition involves overlapping heparin or LMWH with warfarin until stable anticoagulation is achieved. Start warfarin while continuing full-dose heparin or LMWH for at least 5 days and until the INR is in the therapeutic range for at least 24 hours. Once these conditions are met, the heparin can be stopped.

Temporarily Stopping for Surgery or Procedures

Blood thinners must be temporarily stopped before procedures with a risk of bleeding. The waiting period is determined by the medication, kidney function, and the procedure's bleeding risk. Your doctor will provide specific instructions on when to stop the medication. Bridging with a shorter-acting anticoagulant may be used in some cases. For example, Eliquis may need to be stopped 24-48 hours before a procedure, depending on the risk. Kidney function can prolong the interruption period for drugs like dabigatran.

Re-starting Anticoagulation After a Stroke

The timing for restarting anticoagulation after an ischemic stroke balances preventing another clot and avoiding a brain bleed. Guidelines offer recommendations based on stroke severity:

TIA: Restart after 1 day.
Mild Stroke: Restart after 2-3 days.
Moderate Stroke: Wait 6-7 days.
Severe Stroke: Wait 12-14 days.

Brain imaging like a CT scan is necessary before restarting anticoagulation in moderate to severe cases to check for bleeding.

Comparative Table: Waiting Between Blood Thinners


Switching From	Switching To	Waiting/Overlap Time	Key Consideration(s)
DOAC (e.g., Eliquis)	Another DOAC (e.g., Xarelto)	Start new DOAC at time of next scheduled dose of old DOAC.	Straight swap, no overlap needed. Follow dosing frequency of new DOAC.
Warfarin	DOAC	Wait until INR is at target (≤2.0 for Dabigatran/Apixaban; ≤2.5 for Rivaroxaban/Edoxaban) before starting DOAC.	INR monitoring is critical. Can take 2-3 days or more.
DOAC	Warfarin	Overlap both medications until INR is in therapeutic range (2.0-3.0) for at least 2 consecutive days.	Continue DOAC for ~2 days after starting warfarin. Test INR before next DOAC dose.
Heparin/LMWH	Warfarin	Overlap for a minimum of 5 days and until INR is ≥2.0 for at least 24 hours.	Heparin is fast-acting; warfarin is slow. Overlap maintains coverage.
DOAC/Warfarin	None (Surgery)	Varies based on medication, kidney function, and bleeding risk of procedure.	Follow provider instructions precisely. Bridging therapy may be used.
Post-Ischemic Stroke	DOAC/Warfarin	Varies from 1 day (TIA) to 14 days (severe stroke), based on severity.	Requires brain imaging (CT/MRI) before restarting anticoagulation.

Conclusion

The waiting period between blood thinners varies based on the specific drugs, reason for change, and patient health. Due to the complexity, these transitions must always be managed by a healthcare professional. Following their precise instructions is vital for safety. For further information, {Link: American Society of Hematology https://www.hematology.org/-/media/hematology/files/clinicians/guidelines/vte/ashslideset-vteanticoagulationtherapy.pptx} provides detailed guidelines.

Frequently Asked Questions

When switching from Eliquis (apixaban) to Xarelto (rivaroxaban), you should stop taking Eliquis and start Xarelto at the time your next Eliquis dose would have been due. This direct switch is effective because both are DOACs with rapid action.

You should overlap warfarin with full-dose heparin or LMWH for a minimum of 5 days. Continue the overlap until your INR is in the therapeutic range (typically 2.0-3.0) for at least 24 hours. The heparin can then be stopped.

Yes, but only for a specific, medically supervised transition period. When switching from a DOAC to warfarin, they are overlapped for a few days until the INR indicates the warfarin is effective. This should only be done under a doctor's care.

The waiting period before surgery depends on the blood thinner and the bleeding risk of the procedure. For example, for Eliquis, you may need to stop 24 to 48 hours beforehand. Your healthcare provider will give you precise instructions.

There is a waiting period to balance the risk of a new blood clot with the risk of converting the ischemic stroke into a hemorrhagic ( bleeding ) stroke. The timing is determined based on stroke severity, with more severe strokes requiring a longer wait.

If your doctor discontinues a blood thinner, follow their instructions exactly. For some scenarios, like switching to a new medication, they will outline a precise schedule. If stopping permanently, they will advise on how long the medication remains in your system.

Yes. Kidney function can affect the waiting time, especially for DOACs like dabigatran, which are cleared through the kidneys. Patients with impaired renal function may require longer interruption periods for procedures to allow the medication to fully clear.

The waiting time is determined by how quickly your INR drops after you stop warfarin. You will be advised to start the DOAC once your INR reaches a specific target level, which varies by DOAC.