A prescription medication that acts as an immune response modifier and is used to treat genital warts, superficial basal cell carcinoma, and actinic keratosis.

It has no direct antiviral activity, it is a powerful cytokine inducer that stimulates production of interferon alfa, tumor necrosis factor, interleukin (IL) – 1, IL-6, and IL-8. 


Brand name is Aldara.

Generic drug available.

Pregnancy category US: C (Risk not ruled out).

Topical agent

Elimination half-life

30 hours (topical dose), 2 hours (subcutaneous dose).

A patient-applied cream prescribed to treat genital warts, Squamous cell carcinoma in situ, and secondary to surgery, for basal cell carcinoma, as well as actinic keratosis.

Side effects Edit

Side effects include: local inflammatory reactions, blisters, a burning sensation, skin redness, dry skin, itching, skin breakdown, skin crusting or scabbing, skin drainage, skin flaking or scaling, skin ulceration, sores, swelling

May cause systemic reactions, such as fever, “flu-like” symptoms, headache, and tiredness.

Should not used by patients who have had an organ transplant and are taking immune-suppressing drugs.

Imiquimod is a TLR7 agonist.

It signals the immune system through the toll-like receptor 7 (TLR7), a commonly involved in pathogen recognition mechanism.

Cells activated by imiquimod via TLR-7 secrete cytokines interferon-α (IFN-α), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α).

When applied to skin, it can lead to the activation of Langerhans cells, which subsequently migrate to local lymph nodes to activate the adaptive immune system.

It activates natural killer cells, macrophages and B-lymphocytes.

Works on several levels to synergistically to promote antitumoral activity of the compound.

Initially approved as a treatment for superficial basal cell carcinoma.

Imiquimod 5% cream has only modest efficacy for the treatment of squamous cell carcinoma with a cure rate that will be considerably lower than the 75%, but in selected cases where cosmetic outcome is important, it may play a role, as the treated areas heal with little or no scar.

Application of imiquimod 5% cream can result in complete resolution of genital warts in up to 50% of patients. 


No evidence of effectiveness of imiquimod in treating children with molluscum contagiosum, and concerning adverse effects were also noted.

Insufficient evidence exists to recommend treatment of warts, other than genital warts, due to the small size of and lack of controls in existing studies.

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