Imiquimod is an immunomodulator that is used to treat genital or anal warts, actinic keratoses and superficial basal cell carcinoma. While the mechanism of action of imiquimod is not certain, it seems that it works by stimulating the body's immune system. Imiquimod should be used strictly according to the recommendation of the prescribing doctor. Directions for use may differ according to which imiquimod preparation is used.
The human papilloma virus (HPV) causes genital and anal warts, and it is highly contagious. They are also referred to as condylomata acuminata or venereal warts. Imiquimod is used to treat warts in the ano-genital area only, and not internally.
For genital and anal wart treatment, imiquimod is usually used three times a week. After cleaning the area, a thin layer should be applied to the warts and left on for six to ten hours, after which it should be washed off. The treatment may be continued until after the warts are gone, but it shouldn't go on for longer than 16 weeks.
Too much sun exposure may cause rough areas of the skin, called actinic keratoses. They are normally harmless, but in rare cases may progress to skin cancer, so early treatment is vital. Imiquimod is usually applied to the area for four weeks, two or three times a week, and left on for eight hours. The area is then left alone for another four weeks and reassessed by the doctor. If necessary, the treatment may be repeated.
Superficial basal cell carcinoma is most commonly caused by repeated sun exposure over years and so usually occurs on sun-exposed parts of the body, although they may occur anywhere on the body. Imiquimod cream is thought to stimulate the body to attack the cancer cells. For superficial basal cell carcinoma, the cream is usually applied to the affected area and a small area around it five times a week. It should be left in place for eight hours before being washed off. This is done for six weeks, followed by a 12-week treatment-free period and then a reassessment by the doctor.
Imiquimod may be irritating to the skin, so the prescribed dose and duration should not be exceeded. The cream is for external use only and should not be applied to the mucous membranes, near the eyes, lips or nostrils, or to any broken skin. Hands should be washed before and after applying the cream, and it should not be left on for any longer than the prescribed time. Any adverse effects should be reported immediately to the prescribing doctor.