What are the side effects of Voltaren (diclofenac) gel?

From the Guidelines

Voltaren (diclofenac) gel is generally well-tolerated, with a low rate of adverse effects similar to placebo, as shown in a high-quality study 1. When used as directed, common side effects of Voltaren gel are typically mild and localized to the application site.

• Skin reactions such as redness, itching, and rash can occur, but are usually not severe.
• Some users may experience burning, stinging, or warmth at the application site.
• Systemic side effects are less common with topical diclofenac compared to oral forms, but can still occur, especially with prolonged use or application to large areas.
• These may include digestive issues, headaches, dizziness, and rarely, liver or kidney problems.
• Allergic reactions are possible, although rare, and require immediate medical attention if symptoms like swelling, severe rash, or difficulty breathing develop. According to the 2018 update of the EULAR recommendations for the management of hand osteoarthritis 1, pooled safety data from randomized clinical trials comparing topical diclofenac gel with placebo showed similar low rates of adverse effects in subgroups of low-risk versus high-risk patients. To minimize side effects, it is recommended to apply only the recommended amount to intact skin, avoid covering the area with bandages unless directed, wash hands thoroughly after application, and avoid sun exposure to treated areas. People with aspirin allergies, asthma, or a history of stomach ulcers should use this medication cautiously and discuss risks with their healthcare provider, as the safety profile of topical NSAIDs like diclofenac gel is generally favorable compared to oral analgesics 1.

From the FDA Drug Label

The most common adverse events with diclofenac sodium topical solution were application site skin reactions. These events were the most common reason for withdrawing from the study Application Site Reactions: In this controlled trial, application site reactions were characterized by one or more of the following: dryness (22%), exfoliation (7%), erythema (4%), pruritus (2%), pain (2%), induration (2%), rash (2%), and scabbing (<1%) Table 1 lists all adverse reactions occurring in >1% of patients receiving diclofenac sodium topical solution, where the rate in the diclofenac sodium topical solution group exceeded vehicle, from a controlled study conducted in patients with osteoarthritis Table 1: Incidence of Adverse Reactions Occurring in >1% of Subjects with Osteoarthritis Using Diclofenac Sodium Topical Solution and More Often than in Subjects with OA Using Vehicle Control (Pooled)

The side effects of Voltaren (diclofenac) gel include:

• Application site reactions:
  • Dryness
  • Exfoliation
  • Erythema
  • Pruritus
  • Pain
  • Induration
  • Rash
  • Scabbing
• Gastrointestinal events:
  • Nausea
  • Diarrhea
  • Dyspepsia
  • Abdominal pain
  • Flatulence
• Cardiovascular events:
  • Increased risk of serious cardiovascular thrombotic events, including myocardial infarction and stroke
• Other adverse reactions:
  • Urinary tract infection
  • Contusion
  • Sinus congestion
  • Pharyngitis
  • Infection
  • Ecchymosis
  • Accidental injury
  • Pruritus (non-application site)
  • Sinusitis
  • Halitosis
  • Application site reaction (not otherwise specified) 2

From the Research

Side Effects of Voltaren Gel

The side effects of Voltaren (diclofenac) gel are similar to those of other nonsteroidal anti-inflammatory drugs (NSAIDs) and are primarily related to prostaglandin inhibition 3. The most common adverse effects include:

• Gastritis
• Peptic ulceration
• Depression of renal function
• Local skin reactions, such as dermatitis 4
• Gastrointestinal adverse events, although less frequent than with oral NSAIDs 4, 5

Systemic Exposure and Adverse Events

Systemic exposure to diclofenac is significantly lower with topical application compared to oral administration 6. However, the incidence of adverse events (AEs) may be higher with topical diclofenac gel compared to vehicle, particularly local skin reactions 6, 4.

Comparison with Other NSAIDs

Diclofenac has a similar side-effect profile to other NSAIDs, but the incidence of certain adverse events may be lower with diclofenac compared to other NSAIDs 3. The concomitant use of proton pump inhibitors (PPIs) with diclofenac can reduce the risk of hospitalization due to peptic ulcer disease 5.

Efficacy and Tolerability

Topical diclofenac gel is effective in reducing pain and inflammation in various conditions, including osteoarthritis and soft-tissue injuries 4, 7. It is generally well-tolerated, with most adverse events being mild and easily resolved 4, 7.