Understanding Diclofenac Gel and Its Purpose
Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) used to treat joint pain caused by osteoarthritis [1.2.3]. The topical gel formulation allows the medicine to be applied directly to the skin over the painful joint, such as the hands, wrists, elbows, knees, ankles, or feet [1.2.3]. This targeted application delivers pain relief with less medication being absorbed into the bloodstream compared to oral diclofenac, which can help limit systemic side effects [1.2.4]. However, even as a topical treatment, there are strict guidelines and warnings about its application to prevent serious health risks.
Critical Areas to Avoid Application
Proper application is key to the safety and efficacy of diclofenac gel. Certain areas of the body are strictly off-limits.
Mucous Membranes and Sensitive Areas
The gel must never be applied to or come in contact with the eyes, nose, or mouth [1.2.1, 1.4.1]. If accidental contact occurs, the area should be rinsed thoroughly with water [1.2.1]. If irritation persists for more than an hour after rinsing, you should contact your doctor [1.2.2].
Damaged or Unhealthy Skin
Diclofenac gel should only be applied to clean, dry, and intact skin [1.2.1]. You should not apply it to areas with:
- Open wounds, cuts, or burns [1.2.2, 1.5.2]
- Skin infections [1.2.2]
- Rashes or eczema [1.2.2]
- Peeling or inflamed skin (exfoliative dermatitis) [1.2.2, 1.4.3]
Applying the gel to damaged skin can increase the absorption of the medication into the body, potentially leading to harmful effects and a higher risk of side effects [1.2.3].
Prohibited Body Areas
Diclofenac gel 1% is specifically indicated for joints like the knees, ankles, feet, hands, wrists, and elbows [1.2.3]. It has not been shown to be effective for strains, sprains, bruises, or sports injuries [1.2.1]. Furthermore, its use on the back, hip, or shoulder has not been well-studied, so it should be avoided in these areas unless directed by a healthcare provider [1.2.4]. Do not apply the gel to more than two body areas at the same time [1.2.1].
Important Precautions After Application
What you do after applying the gel is just as important as where you apply it.
Do Not Cover the Treated Area
You should not apply occlusive dressings or bandages over the skin treated with diclofenac gel [1.6.2]. Likewise, you should not apply external heat, such as from a heating pad, to the treated area [1.6.1]. Both actions can increase the absorption of the drug and the risk of adverse effects [1.2.3]. Wait at least 10 minutes before covering the treated area with clothes or gloves [1.6.2].
Avoid Sun Exposure
Diclofenac can make your skin more sensitive to sunlight, sunlamps, and tanning beds, a condition known as photosensitivity [1.12.4]. This can lead to severe sunburns, blisters, and swelling [1.2.2]. While using the medication, you should avoid or limit sun exposure to the treated areas and wear protective clothing and sunscreen (SPF 30 or higher) when outdoors [1.2.3, 1.12.2].
Other Topical Products
Do not apply other skin products—including sunscreens, lotions, cosmetics, or other topical medications—to the same area where you have applied diclofenac gel [1.4.2]. Wait until the diclofenac gel has dried completely before applying any other products [1.4.2].
Contraindications and High-Risk Groups
Certain individuals should avoid using diclofenac gel altogether.
- Allergies: Do not use if you have ever had an allergic reaction to diclofenac, aspirin, or any other NSAID [1.2.1, 1.2.2]. This includes aspirin-sensitive asthma [1.9.1].
- Heart Surgery: Avoid use right before or after coronary artery bypass graft (CABG) surgery, as it can increase the risk of heart attack or stroke [1.2.2, 1.2.3].
- Pregnancy: Do not use diclofenac gel at 20 weeks or later in pregnancy, as it can cause harm to the unborn baby and complications during delivery [1.7.2, 1.8.2].
- Drug Interactions: Use caution and consult a doctor if you are taking other medications, especially other NSAIDs (oral or topical), blood thinners (like warfarin), antidepressants (SSRIs/SNRIs), certain blood pressure medications (ACE inhibitors, ARBs), or diuretics [1.9.1, 1.9.2].
Topical vs. Oral NSAIDs: A Safety Comparison
| Feature | Diclofenac Gel (Topical) | Oral NSAIDs (e.g., Ibuprofen, Oral Diclofenac) |
|---|---|---|
| Application | Directly on painful joint skin [1.2.4] | Taken by mouth, systemic effect [1.7.1] |
| Gastrointestinal Risk | Lower risk of GI bleeding and ulcers compared to oral NSAIDs [1.11.2, 1.11.3] | Higher risk of GI bleeding, ulcers, and stomach upset [1.7.1, 1.11.2] |
| Cardiovascular Risk | Carries a boxed warning for heart attack and stroke, but studies suggest a lower risk than oral NSAIDs [1.7.4, 1.11.1] | Carries a boxed warning; risk of heart attack and stroke can occur early in treatment [1.2.3, 1.11.1] |
| Local Side Effects | More common; includes skin rash, itching, or irritation at the application site (occurs in about 4% of users) [1.10.1, 1.10.2] | Less common, though systemic skin reactions can occur [1.7.1] |
| Systemic Side Effects | Less common as less drug is absorbed into the bloodstream [1.2.4] | More common; can include headache, dizziness, and kidney problems [1.7.1] |
Conclusion
While diclofenac gel is an effective tool for managing localized arthritis pain with a better safety profile than oral NSAIDs for certain side effects, its use requires strict adherence to safety guidelines [1.11.3]. Never apply it to broken skin, mucous membranes, or unapproved body areas. Always follow post-application precautions regarding heat, bandages, and sun exposure. Consulting with a healthcare provider is essential to ensure it is the right choice for your condition and to understand all potential risks and interactions.
For more detailed drug information, you can visit the FDA's drug information database.
