A 24-year-old woman from Mumbai presents with vaginal discharge and pelvic pain for 10 days. She reports a new sexual partner 2 weeks ago. On examination, mucopurulent cervical discharge is noted with cervical motion tenderness and adnexal tenderness bilaterally. Gram stain of cervical discharge is negative for gram-negative diplococci. Nucleic acid amplification test (NAAT) for *Chlamydia trachomatis* is positive; NAAT for *Neisseria gonorrhoeae* is negative. What is the most appropriate antimicrobial regimen?