The revival of nitric acid for the treatment of anogenital warts

The destruction of small lesions by tissue denaturation (fixation) rather than erosion (acid hydrolysis) is accomplished by nitric acid of moderate strength in which nitric acid reduction products are generated by nitric acid oxidation of added organic acids. Such solutions show a temperature-dependent increase or loss of nitrite during storage, with loss of therapeutic activity when nitrite levels decrease after storage at cooler temperatures. Use of a preparation technique that completely consumes all the oxidizable organic components added to generate nitrite results in a stable preparation that is effective, well tolerated, and convenient in the treatment of anogenital warts (condylomata acuminata). Of 50 patients monitored after treatment with a 6.6 mol/L nitric acid preparation with no residual oxidizable organic agents, results were good in 39 patients, satisfactory in four patients, and unsatisfactory in seven patients. These observations lead to a simplified stable preparation of modest nitric acid concentration with adequate nitrate reduction products for efficacy in the topical ablation of small skin lesions such as condylomata acuminata. Clinical Pharmacology and Therapeutics (1993) 54, 107–111; doi:10.1038/clpt.1993.118