Since the 1993 treatment guidelines for sexually transmitted diseases were published by the Centers for Disease Control and Prevention, experience has indicated that the regimens recommended then remain largely effective. The recommended therapies—with azithromycin (1 g orally, once), ceftriaxone (250 mg intramuscularly, once), or erythromycin (500 mg orally, four times a day for 7 days)—appear highly effective in the United States; limited data from Kenya suggest that the ceftriaxone regimen may not be as effective there as it once was. The alternative regimen of ciprof oxacin proposed in 1993 (500 mg orally, twice a day for 3 days) is as effective as the recommended therapies, but new information indicates that single-dose therapy with 500 mg orally is not as effective as the use of either larger single doses or more prolonged therapy. Persons who are infected with human immunodef ciency virus (HIV) do not respond as well as those who are not HIV-infected, and males who are uncircumcised appear not to respond as well as those who are circumcised.