From the Guidelines
Imiquimod cream, commonly known as Aldara, is a topical immune-response modifier used to treat various skin conditions, including actinic keratosis, and is applied at night and washed off in the morning 8 hours later, with courses of three times a week for 4 weeks, which can be repeated for a further 4 weeks if needed. According to the British Association of Dermatologists' guidelines for the care of patients with actinic keratosis 2017 1, Imiquimod 5% cream has a strength of recommendation A, level of evidence 1++, indicating its effectiveness in treating actinic keratosis. The medication is available as a 5% and a 3.75% cream, with most data on treatment response pertaining to the 5% cream. Key points to consider when using Imiquimod cream include:
- It is licensed for use in clinically typical, non-hyperkeratotic, non-hypertrophic AKs on the face or scalp in immunocompetent adults 1
- A meta-analysis of five RCTs demonstrated a 50% complete clearance rate when used two or three times a week for 12-16 weeks 1
- Side-effects are generally well tolerated, but patients should be counseled carefully to anticipate those who may have more extreme clinical reactions 1
- About 50% of patients discontinue treatment at 6 weeks due to disappearance of the AK 1 It is essential to follow the prescribed treatment course and application instructions to ensure the best possible outcomes and minimize potential side effects.
From the FDA Drug Label
Imiquimod Cream, 5% is an immune response modifier for topical administration. Each gram contains 50 mg of imiquimod in an off-white oil-in-water vanishing cream base consisting of benzyl alcohol, cetyl alcohol, glycerin, methylparaben, oleic acid, oleyl alcohol, polysorbate 60, propylparaben, purified water, stearyl alcohol, sorbitan monostearate, white petrolatum, and xanthan gum. Chemically, imiquimod is 1-(2-methylpropyl)-1H-imidazo[4,5-c]quinolin-4-amine. Imiquimod has a molecular formula of C14H16N4 and a molecular weight of 240.3.
Imiquimod (Aldara) cream is an immune response modifier for topical administration, containing 50 mg of imiquimod per gram of cream. 2
From the Research
Definition and Uses of Imiquimod (Aldara) Cream
- Imiquimod (Aldara) is an immune response modulator used for the treatment of various skin conditions, including external anogenital warts, superficial basal cell carcinoma, and actinic keratoses 3, 4, 5, 6, 7.
- It is applied as a 5% cream, typically two to five times per week, for varying periods depending on the indication 3.
- The cream works by inducing cytokines, which stimulate the immune system to recognize and eradicate viral infections or tumors 5, 6.
Mechanism of Action and Effects
- Imiquimod exhibits antiviral and antitumor effects by inducing cytokines such as interferon alpha, interleukin-12, and tumor necrosis factor alpha 5, 6.
- It acts as an agonist for toll-like receptor 7, triggering the immune system to recognize the presence of a viral infection or tumor 6.
- The treatment can lead to local skin reactions, which are generally well tolerated, and systemic reactions have been reported 3, 6.
Treatment Outcomes and Efficacy
- Topical imiquimod 5% cream has been shown to be an effective treatment option for actinic keratosis, producing complete eradication or marked reduction in the number of lesions in most patients 7.
- The treatment can also lead to the emergence of subclinical lesions during treatment of the affected skin region ["field treatment"] 7.
- There is evidence that topical imiquimod can at least partially reverse some of the cellular, molecular, and genetic photocarcinogenic changes that develop in skin damaged by UV light 7.