Abstract: Objective To evaluate the efficacy and safety of imiquimod 5% cream applied with different treatment courses for preventing the recurrence of condyloma acuminatum lesions.Methods A randomized,controlled clinical trial was conducted.Patients with condyloma acuminatum were divided into 3 groups (Group A,B and C).Group A was treated with CO₂ laser only.Group B was given topical imiquimod 5% cream three times a week over 4 weeks after laser treatment of visible warts.Group C was given topical imiquimod 5% cream three times a week over 8 weeks after laser treatment of visible warts.All patients were followed up for 6 months.Results A total of 90 patients with anogenital warts were enrolled in,and finished the study.The recurrence rates of the Group A,B,and C were 64.29%,50%,21.88%,respectively,in 6 months of follow-up.The recurrence rate was statistically lower in Group C than in Group A and B (P=0.0033),and in Group C than in Group B (P=0.0457).Adverse reactions occurred in 73.33% and 84.38% of patients in Group B and C,respectively,which included erythema,itching,pain, burning,erosion,ulceration and flu-like symptoms.There was no significant difference of the frequencies of adverse reactions between Group B and C (P>0.05).Conelusion The recurrence rate of anogenital warts declines significantly in patients treated with imiquimod 5% cream for 8 weeks,but not in the 4 weeks group,after laser therapy.The frequencies of adverse reactions are not significantly different in both groups.

Key words: Condylomata acuminata, Recurrence, Chemoprevention, Imiquimod