Safety of Diclofenac 10% Gel in Patients with CAD
Diclofenac 10% gel should be avoided in patients with coronary artery disease (CAD) due to FDA contraindication and increased cardiovascular risk, particularly for myocardial infarction and stroke. 1
FDA Labeling and Contraindications
The FDA drug label for topical diclofenac carries a black box warning specifically addressing cardiovascular risks: 1
- NSAIDs, including topical diclofenac, cause an increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke, which can be fatal 1
- This risk may occur early in treatment and increases with duration of use 1
- Diclofenac sodium topical solution is contraindicated in the setting of coronary artery bypass graft (CABG) surgery 1
- The FDA explicitly warns to avoid use of diclofenac in patients with a recent MI unless benefits outweigh the risk of recurrent CV thrombotic events 1
- Patients with known CV disease or risk factors have a higher absolute incidence of excess serious CV thrombotic events due to their increased baseline rate 1
Evidence-Specific to Diclofenac in CAD
Among NSAIDs, diclofenac carries particularly elevated cardiovascular risk in CAD patients: 2, 3
- In patients with a history of coronary artery disease, diclofenac appears to carry the greatest risk among NSAIDs and all NSAIDs should be avoided 2
- In patients recently hospitalized for serious coronary heart disease, diclofenac users had a 1.86-fold increased risk of serious coronary events (95% CI 1.18-2.92) compared to NSAID non-users 3
- Compared directly to naproxen (the safest NSAID), diclofenac showed 1.44-fold increased risk of serious coronary heart disease (95% CI 0.96-2.15, P=0.076) and 1.52-fold increased risk of serious cardiovascular disease/death (95% CI 1.22-1.89, P=0.0002) 3
- Diclofenac's high COX-2 inhibitory potency is associated with its relatively higher risk of myocardial infarction, similar to that of rofecoxib 4
Systemic Absorption Considerations
While topical formulations have lower systemic absorption than oral NSAIDs, the cardiovascular risks remain: 1
- The FDA warning applies to all formulations of diclofenac, including topical preparations 1
- Clinical trials demonstrating increased cardiovascular risk included various NSAID formulations and durations 1
- Even short-term NSAID therapy is not without cardiovascular risk 1
Alternative Pain Management Strategies
For CAD patients requiring analgesia, safer alternatives include: 5, 6
- Acetaminophen as first-line for mild-to-moderate pain, though some uncertainty exists about cardiovascular effects at high doses 2
- Naproxen if an NSAID is absolutely necessary, as it carries the lowest cardiovascular risk among NSAIDs (incidence rate ratio 0.88,95% CI 0.66-1.17 for serious coronary events) 3
- Non-pharmacologic therapies including physical therapy, exercise, and cardiac rehabilitation are recommended for all CCD patients 5
Clinical Monitoring if Use is Unavoidable
If diclofenac gel must be used despite CAD (extremely rare circumstances): 1
- Use the lowest effective dose for the shortest duration possible 1
- Monitor patients for signs of cardiac ischemia including changes in angina frequency or severity 1
- Remain alert for symptoms of serious CV events throughout the entire treatment course 1
- Consider that patients on aspirin for cardiac prophylaxis require closer monitoring for GI bleeding when NSAIDs are added 1
Common Pitfalls to Avoid
- Do not assume topical formulations are safe simply because of reduced systemic absorption—the FDA contraindication applies to all diclofenac formulations 1
- Avoid concurrent use with oral NSAIDs, which compounds cardiovascular risk 1
- Do not use in post-MI patients within the first year, as observational studies show 20 deaths per 100 person-years in NSAID-treated patients versus 12 per 100 person-years in non-exposed patients 1
- Be aware that the increased relative risk of death in NSAID users persists for at least four years post-MI 1