Can diclofenac (Nonsteroidal Anti-Inflammatory Drug (NSAID)) be given with aspirin (acetylsalicylic acid (ASA))?

Diclofenac Can Be Given with Aspirin, But Requires Specific Precautions

Diclofenac can be given with aspirin, but this combination requires careful monitoring for increased gastrointestinal risks and appropriate gastroprotection measures should be implemented.

Rationale for Compatibility

Diclofenac, unlike some other NSAIDs such as ibuprofen, does not interfere with the cardioprotective effects of aspirin. According to the European Society of Cardiology guidelines, "Diclofenac is a relatively COX-2 selective NSAID and therefore a poor platelet inhibitor, but does not interfere with the antiplatelet effects of aspirin and may be used in combination with aspirin" 1.

This makes diclofenac a preferred NSAID option when aspirin therapy is required for cardiovascular protection, especially compared to ibuprofen which can reduce aspirin's cardioprotective benefits.

Risks of Combination Therapy

However, this combination does come with important risks:

1. Increased GI Risk: The concomitant use of aspirin with any NSAID, including diclofenac, significantly increases the risk of gastrointestinal bleeding and ulceration. According to the American Gastroenterological Association consensus, "When low-dose aspirin users add a non-selective NSAID, the risk may increase by two- to four-fold when compared with the use of low-dose aspirin alone" 1.

2. Renal Effects: Both medications can affect renal function, particularly in patients with heart failure or those taking ACE inhibitors 2.

Required Precautions

When prescribing diclofenac with aspirin, the following precautions should be implemented:

1. Gastroprotection

• Add a proton pump inhibitor (PPI): This is strongly recommended to reduce the risk of GI complications. According to the American College of Rheumatology, "When NSAIDs are combined with aspirin, the annual risk of upper gastrointestinal events increases significantly" 1.
• PPIs can reduce the rate of endoscopic NSAID-related ulcers by up to 90% 1.

2. Patient Selection

• Avoid in high-risk patients: This combination should be avoided in patients with:
  • History of peptic ulcer disease or GI bleeding
  • Advanced age (≥60 years)
  • Concurrent corticosteroid or anticoagulant therapy 1
  • Severe renal impairment (eGFR <30 ml/min) 1
  • Decompensated heart failure 2

3. Monitoring

• Monitor for signs of GI bleeding (epigastric pain, melena, hematemesis)
• Monitor renal function, especially in patients with heart failure or on ACE inhibitors
• Monitor blood pressure, as both medications can increase blood pressure 3

Special Considerations

• Dose and Duration: Use the lowest effective dose of diclofenac for the shortest duration possible to minimize risks 4.
• Timing of Administration: Unlike ibuprofen, there are no specific timing requirements for administering diclofenac relative to aspirin 1, 5.
• FDA Warning: The FDA drug label for diclofenac specifically mentions: "Concomitant use of diclofenac potassium tablets and analgesic doses of aspirin is not generally recommended because of the increased risk of bleeding" 3. However, this is a general precaution for all NSAIDs, and diclofenac is still preferred over ibuprofen when aspirin must be used.

Conclusion

While diclofenac can be given with aspirin and is preferred over ibuprofen in this situation, this combination increases GI risks and requires appropriate gastroprotection with a PPI. The decision to use this combination should consider the patient's cardiovascular and gastrointestinal risk factors, with careful monitoring for adverse effects.