Systematic review of intralesional Cidofovir dosing regimens in the treatment of recurrent respiratory papillomatosis

Abstract Objective Surgical management of recurrent respiratory papillomatosis (RRP) usually involves resection via microlaryngoscopy. Intralesional injection of cidofovir has been shown to be an effective adjuvant treatment, but remains unlicensed. United Kingdom General Medical Council guidelines recommend the prescribing doctor should “be satisfied that there is a sufficient evidence base and/or experience of using the medicine to demonstrate its safety and efficacy”. This study reviews the published dosing regimens of intralesional cidofovir in the treatment of RRP in order to provide a precedent for those that wish to prescribe it. Methods A systematic review of the literature was undertaken using Medline, EMBASE and CINAHL. Articles describing the use of intralesional cidofovir for RRP were reviewed. Information regarding cidofovir concentration, volume, total dose, number of treatments, interval between treatments, overall treatment period and follow up was extracted. Results Fifty-one articles were identified. Concentration of cidofovir injected ranged from 0.0001 mg/ml to 37.5 mg/ml, with 5 to 7.5 mg/ml being the most common. The volume of cidofovir solution injection ranged from 0.1 to 20 ml. The total dose per injection ranged from 0.15 to 105 mg. There was wide variation in dosing regimens with different intervals between endoscopies, number of injections and total doses delivered. Conclusions Based on this published literature, the precedent for prescribing intralesional cidofovir supports a concentration of 5 to 7.5 mg/ml. Volumes up to 5 ml per injection are routinely used. Total dose and frequency of cidofovir administration is highly variable. The need for repeat doses of cidofovir should be judged on an individual basis.