Is it safe to use diclofenac (Diclofenac) gel in a patient with a hypersensitivity reaction to oral ibuprofen (Ibuprofen)?

From the Guidelines

Patients with a hypersensitivity reaction to oral ibuprofen should exercise caution when using diclofenac gel, but it may be considered as a treatment option due to its favorable safety profile and low risk of adverse effects, as shown in a high-quality study published in 2019 1. When considering the use of diclofenac gel in a patient with a hypersensitivity reaction to oral ibuprofen, it is essential to weigh the potential benefits against the risks.

• The risk of cross-reactivity between ibuprofen and diclofenac, both of which are non-steroidal anti-inflammatory drugs (NSAIDs), must be taken into account.
• However, topical diclofenac gel has been shown to have a favorable safety profile compared to oral analgesics, with similar low rates of adverse effects in both low-risk and high-risk patients 1.
• The fact that less medication is absorbed into the bloodstream with topical application may also reduce the risk of an adverse reaction. Some key points to consider when making this decision include:
• The severity of the patient's previous reaction to ibuprofen
• The potential benefits of using diclofenac gel, such as its effectiveness in reducing pain and improving function in patients with osteoarthritis
• The availability of alternative treatment options, such as acetaminophen or topical capsaicin, which may be recommended if the risk of cross-reactivity is deemed too high. Ultimately, the decision to use diclofenac gel in a patient with a hypersensitivity reaction to oral ibuprofen should be made on a case-by-case basis, taking into account the individual patient's medical history and the potential risks and benefits of treatment, as supported by the 2019 study published in the Annals of the Rheumatic Diseases 1.

From the FDA Drug Label

Diclofenac sodium topical solution is contraindicated in the following patients: Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to diclofenac or any components of the drug product History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, sometimes fatal, anaphylactic reactions to NSAIDs have been reported in such patients

Key Considerations:

• The patient has a hypersensitivity reaction to oral ibuprofen, which is an NSAID.
• Diclofenac is also an NSAID, and the label warns about cross-reactivity between aspirin and other NSAIDs in patients with aspirin-sensitive asthma.
• The label does not specifically address the safety of using diclofenac gel in a patient with a hypersensitivity reaction to oral ibuprofen.

Answer: It is not safe to use diclofenac gel in a patient with a hypersensitivity reaction to oral ibuprofen, as there is a potential for cross-reactivity between NSAIDs 2.

From the Research

Safety of Diclofenac Gel in Patients with Hypersensitivity to Oral Ibuprofen

• The safety of using diclofenac gel in patients with a hypersensitivity reaction to oral ibuprofen is not directly addressed in the provided studies 3, 4, 5, 6, 7.
• However, the studies suggest that topical diclofenac has a lower systemic bioavailability compared to oral diclofenac 5, which may reduce the risk of systemic adverse events.
• Local skin reactions are a common adverse event associated with topical diclofenac, but they are generally mild and transient 4, 5, 7.
• There is no evidence to suggest that a hypersensitivity reaction to oral ibuprofen would necessarily lead to a similar reaction to topical diclofenac, as the two drugs have different mechanisms of action and are administered through different routes 6.
• The decision to use diclofenac gel in a patient with a hypersensitivity reaction to oral ibuprofen should be made on a case-by-case basis, taking into account the individual patient's medical history and the potential benefits and risks of the treatment.

Efficacy of Diclofenac Gel in Musculoskeletal Pain

• Topical diclofenac has been shown to be effective in reducing pain in acute and chronic musculoskeletal conditions, including osteoarthritis and sprains 3, 4, 7.
• The efficacy of diclofenac gel can vary depending on the formulation and the specific condition being treated 4, 7.
• The number needed to treat (NNT) for diclofenac gel can range from 1.8 to 9.5, depending on the formulation and the condition being treated 4, 7.

Comparison of Topical and Oral NSAIDs

• Topical NSAIDs, including diclofenac, have been shown to have a lower risk of systemic adverse events compared to oral NSAIDs 3, 4.
• The efficacy of topical NSAIDs can be similar to that of oral NSAIDs, but the optimal formulation and dosage may vary depending on the specific condition being treated 4, 7.