What are the bleeding risks associated with Voltarem (diclofenac) gel?

Bleeding Risks Associated with Voltaren (Diclofenac) Gel

Topical diclofenac gel carries a significantly lower risk of bleeding compared to oral NSAIDs, but systemic absorption can still occur and may cause bleeding complications, particularly in high-risk patients. 1, 2

Mechanism of Bleeding Risk

Diclofenac, like other NSAIDs, can increase bleeding risk through several mechanisms:

• Inhibition of cyclooxygenase (COX) enzymes, particularly COX-2, which affects platelet function 3
• Potential gastrointestinal mucosal damage, even with topical formulations due to systemic absorption 4
• Enhanced antiplatelet effects when combined with other medications that affect blood clotting 2

Bleeding Risk Profile of Topical Diclofenac

Advantages of Topical vs. Oral NSAIDs

• Topical diclofenac formulations result in substantially lower systemic exposure compared to oral diclofenac 3
• The FDA label notes that topical formulations generally have a more favorable side effect profile than oral NSAIDs 2

Documented Bleeding Risks

• Case reports exist of upper gastrointestinal hemorrhage associated with cutaneous application of diclofenac gel 4
• Lower gastrointestinal bleeding has been reported with diclofenac topical patch use, particularly in patients with underlying risk factors 5

High-Risk Patient Groups

Patients at increased risk for bleeding complications with topical diclofenac include:

1. Patients with cardiovascular risk factors

   • Diclofenac may increase risk of thrombotic events, which can lead to secondary bleeding complications 1
   • Patients with recent myocardial infarction should avoid diclofenac when possible 2

2. Patients with gastrointestinal risk factors

   • History of peptic ulcer disease or GI bleeding 4
   • Elderly patients (≥75 years) 1
   • Patients with active gastroduodenal ulcers 6

3. Patients on anticoagulant or antiplatelet therapy

   • Concomitant use with warfarin, other anticoagulants, antiplatelet agents, SSRIs, or SNRIs increases bleeding risk 2
   • Particularly high risk in patients with atrial fibrillation on antiplatelet therapy 5

4. Patients with renal impairment

   • NSAIDs, including topical diclofenac, can affect renal function and increase bleeding risk 1

Monitoring and Precautions

• Monitor hemoglobin or hematocrit in patients with any signs or symptoms of anemia 2
• For patients on long-term NSAID treatment, consider periodic monitoring with CBC and chemistry profile 2
• Avoid concurrent use of topical diclofenac with oral NSAIDs, as this combination has resulted in higher rates of rectal hemorrhage 2
• Patients with a history of peptic ulcer should exercise caution when using topical diclofenac formulations 4

Risk Mitigation Strategies

1. Use lowest effective dose for shortest duration

   • The American College of Clinical Pharmacology advises not exceeding recommended daily doses 1
   • Higher doses significantly increase GI and CV risks 1

2. Consider gastroprotective agents

   • Proton pump inhibitors are preferred over H2 blockers for patients with GI risk factors 1

3. Avoid combination therapy

   • Do not use combination therapy with diclofenac gel and an oral NSAID unless the benefit outweighs the risk 2
   • Avoid concomitant use with other medications that increase bleeding risk when possible 2

4. Patient education

   • Advise patients about signs and symptoms of bleeding and when to seek medical attention 6
   • Instruct patients to avoid exposure to natural or artificial sunlight on treated areas 2

Conclusion

While topical diclofenac generally has a better safety profile than oral NSAIDs, clinicians should remain vigilant about potential bleeding complications, particularly in high-risk patients. Systemic absorption does occur, and case reports demonstrate that serious bleeding events are possible, especially in patients with underlying risk factors or those taking other medications that affect coagulation.