Characterization of Doxycycline Pharmacokinetics and Adherence

Exclusion criteria

• . Per participant report, planned or active use of any anticonvulsants at screening and an unwillingness to restrict use of certain medications (iron, antacids, etc.) for the duration of the study
• . For females of reproductive potential: Pregnant or currently breastfeeding, or intends to become pregnant and/or breastfeed during the study
• . Has any of the following laboratory abnormalities:
• . An estimated calculated creatinine clearance (CrCl) less than 60 mL/min by the Cockcroft-Gault formula at screening
• . Positive for hepatitis B surface antigen (HBsAg) at screening
• . Has a Grade 2 or higher clinically significant laboratory abnormality as defined by The Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events, Corrected Version 2.1 - July 2017 (exception: a CrCl ≥ 60 mL/min at enrollment is permissible for enrollment)
• . Per participant reported symptoms or clinical and/or laboratory diagnosis of an active pharyngeal, anorectal, or reproductive tract infection (RTI) requiring treatment at screening and enrollment per current US Centers for Disease Control and Prevention (CDC) guidelines (https://www.cdc.gov/std/treatment-guidelines/default.htm). Infections requiring treatment include Neisseria gonorrhoeae (GC), Chlamydia trachomatis (CT), syphilis, active herpes simplex virus (HSV) lesions, or symptomatic genital warts, chancroid, pelvic inflammatory disease (PID), bacterial vaginosis (BV), symptomatic vaginal candidiasis, and trichomoniasis
• . Participation in research studies involving drugs, products, or vaccines within 30 days of the enrollment and for the duration of the study