What are the risks of receiving a steroid injection while on anticoagulant (blood thinner) therapy, such as warfarin or direct oral anticoagulants (DOACs) like rivaroxaban?

Risks of Receiving Steroid Injections While on Blood Thinners

Patients on blood thinners (anticoagulants) who receive steroid injections face an increased risk of bleeding complications, particularly with high-risk procedures, though the absolute risk remains relatively low for most injection types.

Major Bleeding Risks

Risk Factors

• Type of blood thinner:
  • Warfarin: Higher bleeding risk when INR >1.5 1
  • Direct Oral Anticoagulants (DOACs): Risk depends on timing of last dose and renal function 1
  • Heparins: Increased risk with unfractionated heparin (UFH) and low molecular weight heparin (LMWH) 1

Procedure-Related Risk Factors

• Higher risk procedures:
  • Spinal/epidural injections (risk of epidural hematoma)
  • Interventional procedures requiring larger gauge needles
  • Multiple needle passes or insertions at multiple levels
  • Accidental dural puncture 2

Patient-Related Risk Factors

• Advanced age
• Renal impairment (especially with dabigatran)
• History of bleeding disorders
• Concomitant use of other medications that affect coagulation (NSAIDs, aspirin) 1

Specific Risks by Injection Type

Neuraxial (Spinal/Epidural) Injections

• Highest risk procedure due to potential for spinal/epidural hematoma
• Can result in permanent neurological damage if not promptly diagnosed and treated
• Warning signs: Progressive back pain with radicular distribution, motor/sensory impairment, altered bowel/bladder function within 24 hours 1

Peripheral Joint Injections

• Generally lower risk than neuraxial procedures
• Potential for joint hematoma, though usually self-limiting
• Risk increases with deeper or vascular-rich target areas

Risk Management Strategies

For Warfarin

• For high-risk procedures: Stop warfarin 5 days before procedure and ensure INR <1.5 1
• For low-risk procedures: May continue warfarin if INR is in therapeutic range 3

For DOACs

• For high-risk procedures: Last dose should be taken 3 days before procedure
• For patients on dabigatran with CrCl 30-50 mL/min: Last dose 5 days before procedure
• For low-risk procedures: Omit morning dose on day of procedure 1

For Antiplatelet Medications

• Low-dose aspirin (<100mg/day): Generally safe to continue for most procedures 2
• Clopidogrel and other P2Y12 inhibitors: Higher bleeding risk, especially for neuraxial procedures

Balancing Risks

The decision to continue or discontinue blood thinners before steroid injections must balance:

1. Bleeding risk from continuing anticoagulation
2. Thrombotic risk from discontinuing anticoagulation

For patients at high thrombotic risk (mechanical heart valves, recent VTE, atrial fibrillation with high CHADS2 score), discontinuing anticoagulation may pose greater risks than the bleeding risk of the procedure 1.

Monitoring and Management

• Post-procedure monitoring for signs of bleeding
• Prompt recognition of neurological symptoms if neuraxial procedure performed
• Restart anticoagulation according to procedure risk:
  • Low-risk procedures: Same day
  • High-risk procedures: 24-48 hours post-procedure 1

Important Caveats

• Recent research suggests that continuing certain anticoagulants during some procedures may be safer than previously thought 3
• The risk of medical complications from stopping warfarin may exceed the risk of bleeding complications in some patients 3
• Individualized risk assessment is crucial, considering both the specific anticoagulant and the specific injection procedure

Remember that prompt recognition and management of bleeding complications is essential to prevent long-term sequelae, particularly with neuraxial procedures.