A 33-year-old cisgender man who has sex only with cisgender men presents for a return visit for evaluation of persistent urethral symptoms. Two weeks prior, he was seen with urethral pruritus and a mucoid penile discharge. He was empirically treated for nongonococcal urethritis with doxycycline 100 mg orally twice a day for 7 days. Nucleic acid amplification tests (NAATs) for Chlamydia trachomatis and Neisseria gonorrhoeae were negative. He continues to have the same symptoms. He reports that he took all doses of doxycycline, and he has not had any sexual contact since starting the treatment. On physical examination, a mucoid urethral discharge is observed. He weighs 74 kg.