Is topical diclofenac gel safe for a patient with recent myocardial infarction, three coronary stents, and on dual antiplatelet therapy who has musculoskeletal chest pain?

Is Diclofenac Gel Safe in This Clinical Context?

No, diclofenac gel is not safe for this patient with recent myocardial infarction, three coronary stents, and dual antiplatelet therapy. Even topical formulations carry significant cardiovascular risk in post-MI patients and should be avoided.

Cardiovascular Risk in Post-MI Patients

The FDA drug label explicitly warns against using diclofenac in patients with recent MI, stating that observational studies from the Danish National Registry demonstrated NSAID-treated patients in the post-MI period were at increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week of treatment 1. The incidence of death in the first year post-MI was 20 per 100 person years in NSAID-treated patients compared to 12 per 100 person years in non-NSAID exposed patients 1.

• Large observational studies showed diclofenac specifically carries hazard ratios for death of 2.40 (95% CI 2.09-2.80) in first-time MI patients, with dose-related increases in risk of death and non-dose-dependent trends for rehospitalization for MI 2.
• The increased relative risk of death in NSAID users persisted over at least four years of follow-up post-MI 1.
• Clinical trials have shown NSAIDs increase the risk of serious cardiovascular thrombotic events, including MI and stroke, which can be fatal, with this risk appearing as early as the first weeks of treatment 1.

Systemic Absorption from Topical Formulations

Topical diclofenac is NOT free from systemic cardiovascular risk. While topical formulations reduce gastrointestinal side effects compared to oral NSAIDs, they still achieve measurable systemic drug levels 3.

• The FDA label states that physicians and patients should remain alert for cardiovascular events throughout the entire treatment course, even with topical formulations 1.
• Diclofenac's specific pharmacology alters vascular levels of platelet-active prostaglandins in a way that favors arterial thrombosis, similar to selective COX-2 inhibitors 4.

Interaction with Dual Antiplatelet Therapy

The combination of diclofenac with dual antiplatelet therapy (aspirin plus clopidogrel/prasugrel/ticagrelor) creates additional bleeding risk without mitigating cardiovascular thrombotic risk 1.

• The FDA label explicitly states there is no consistent evidence that concurrent use of aspirin mitigates the increased risk of serious CV thrombotic events associated with NSAID use 1.
• Concurrent use of aspirin and diclofenac increases the risk of serious gastrointestinal events 1.

Recommended Alternative Approach for Musculoskeletal Chest Pain

Use a stepped-care algorithm that avoids all NSAIDs:

1. First-line: Acetaminophen up to 4000 mg/day in divided doses 2.
2. Second-line: Small doses of narcotics (short-acting opioids for breakthrough pain only) 2.
3. Third-line: Non-acetylated salicylates (e.g., salsalate, which do not inhibit platelet function) 2.

All NSAIDs—including topical diclofenac—should be completely avoided in this patient 2.

Critical Guideline Recommendations

The ACC/AHA guidelines provide explicit Class III recommendations (meaning "should not be done") for NSAIDs in post-MI patients:

• NSAIDs with increasing degrees of relative COX-2 selectivity should not be administered to post-MI patients when therapy with acetaminophen, small doses of narcotics, or non-acetylated salicylates provides acceptable levels of pain relief 2.
• The FDA label advises to "avoid the use of diclofenac sodium topical solution in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events" 1.

Common Pitfall to Avoid

Do not assume topical NSAIDs are "safe" alternatives in high-risk cardiovascular patients. While topical formulations reduce GI toxicity, they do not eliminate cardiovascular thrombotic risk, which is the primary concern in this post-MI patient with stents 1, 4.