Actinic keratosis (AK; also called solar keratosis) is a common precancerous skin condition that appears as a dry, scaly lesion caused by prolonged and repeated sun exposure. Approximately 10% of AKs ultimately become cancerous, and nearly half of all squamous cell carcinomas (a type of skin cancer) begin as untreated AKs. Current treatment options for AK include cryosurgery (freezing), curettage (scraping), surgical excision (removal), laser therapy, chemical peels, photodynamic therapy, and topical (applied to skin only) creams such as imiquimod, fluorouracil and diclofenac. If your doctor has prescribed diclofenac, this introduction will arm you with the information you need to use it effectively and safely.
Note: This information may not cover all possible precautions, interactions or adverse effects for this drug. If you have any questions about any drug you are taking, be sure to check with your healthcare professional.
Other Names for Diclofenac (United States)
Solaraze, diclofenac 3% gel, diclofenac sodium
Diclofenac gel is a skin-use only (topical) prescription medicine used to treat actinic keratosis on all areas of the body. Although the exact way it works is not completely understood, it is classified as a nonsteroidal anti-inflammatory drug (NSAID), just like aspirin and ibuprofen. NSAIDs inhibit a molecule in the body called cyclo-oxygenase-2 (COX-2), which in turn reduces the synthesis of a hormone-like substance called prostaglandin. Sun damage and AKs have been linked with raised prostaglandins in the skin.
Evidence for the Effectiveness of Diclofenac
Three clinical trials were conducted that led to the approval of diclofenac gel by the Food and Drug Administration. A total of 427 patients with five or more AK lesions on their scalp, forehead, face, forearm or hand were treated with either diclofenac or a dummy (placebo) gel for three months. Thirty days after the end of treatment, 30% to 50% of the AK lesions were completely cleared, double or triple the number seen in the dummy gel group. The best results were seen with AKs on the face. A more recent study tested the effect of diclofenac on AKs that had already been treated with cryosurgery (freezing). The results were even better: 46% of the patients saw all of their AK lesions completely cleared compared with only 21% of the patients who didn't receive diclofenac after cryosurgery.
How to Use Diclofenac
Diclofenac gel should be gently smoothed on to your lesions twice a day. The amount needed depends upon the size of the lesion, but be sure that enough is applied to adequately cover each lesion. Your doctor may recommend that you treat a general area with diclofenac, rather than just specific lesions, which may help clear lesions that are not yet visible. The recommended duration of therapy is from 60 days to 90 days. You may not see complete healing of the lesions until 30 days after you stopped using it. If you see that some lesions are not responding to the gel, see your doctor.
Potential Side Effects
In clinical trials, the most common reactions reported involved the skin and were generally mild to moderate in severity. These included:
- itchy rash
- dry skin
- skin peeling
Tell your healthcare provider about all of your medical conditions before starting to use diclofenac gel, including if you:
- have an active ulcer
- have liver problems
- have kidney problems
- have had a previous bad reaction to aspirin, ibuprofen or other NSAIDs
Other cautions to be aware of when using diclofenac gel:
- It is important to avoid the sun and tanning booths while you are using diclofenac gel, since it causes an increased sensitivity to sunburns.
- It should not be applied to open skin wounds, infections or other skin problems.
- It should not be allowed to come in contact with the eyes.
- It should not be taken by pregnant or nursing women or children.
Berlin JM, Rigel DS. Diclofenac sodium 3% gel in the treatment of actinic keratoses postcryosurgery. J Drugs Dermatol. 2008 7(7):669-73. 23 January 2009.
Nelson CG, Spencer J, Nelson CG Jr. A single-arm, open-label efficacy and tolerability study of diclofenac sodium 3% gel for the treatment of actinic keratosis of the upper and lower lip. J Drugs Dermatol. 2007 6(7):712-717. 23 January 2009.
Newman MD, Weinberg JM. Topical therapy in the treatment of actinic keratosis and basal cell carcinoma. Cutis. 2007 79(4 Suppl):18-28. 23 January 2009.
"Solaraze Gel Prescribing Information." PharmaDerm. 23 January 2009.