Imiquimod
Imiquimod is a an immune response modifier. It is manufactured as a 5% cream called Aldara™. Imiquimod is mainly used to treat genital warts, solar keratoses and basal cell skin cancers.
Imiquimod works by stimulating the immune system to release a number of chemicals called cytokines, which are important in fighting viruses and destroying cancer cells.
When used to treat skin cancers and pre-cancerous lesions it results in inflammation, which destroys the lesion. The degree of inflammation is quite variable from person to person, in part due to the type of skin lesion and in part due to genetic factors. The imiquimod is taken up by the so-called ‘toll-like receptor 7’ on certain immune cells that are found in the outside part of the skin (the epidermis); these receptors are expressed more in some individuals and in some skin lesions than in others.
Imiquimod is particularly useful on areas where surgery or other treatments may be difficult, complicated or otherwise undesirable, especially the face and lower legs.
A course of treatment ranges from 4 to 16 weeks. Before starting, a biopsy may be performed to confirm the diagnosis. Your doctor should carefully monitor the treatment because you may need to apply the cream more or less frequently than originally planned or for a shorter or longer course, depending on response. Once the inflammation has settled there is generally a good or excellent cosmetic result with little scarring.
Imiquimod is particularly useful for:
- Solar keratoses (also called actinic keratoses or SKs).
- Basal cell carcinoma (BCC), especially superficial types
- Bowen disease, also known as in-situ squamous cell carcinoma (SCC), an unregistered indication at this time (June 2008)
