title: Doxycycline serum levels at the time of dilation and evacuation with two dosing regimens.
abstract: BACKGROUND
  Doxycycline is commonly used for antibiotic prophylaxis before dilation and evacuation (D&E) but frequently causes nausea and emesis which may affect absorption and effectiveness. Taking doxycycline the night prior to surgery may result in adequate absorption with better tolerance.
  
  
  METHODS
  We enrolled 40 women into a double-blind randomized comparison of doxycycline 200 mg given 4 h before D&E (Group 1) vs. the night prior to D&E with dinner (Group 2). D&E procedures were scheduled after 11 a.m. and subjects were nil per os on the morning of the procedure. Subjects completed symptom diaries from dilator placement until the D&E. Serum for doxycycline assays was obtained before the D&E.
  
  
  RESULTS
  Mean gestational age was 19.4 weeks (range 15.8-22.0 weeks) and did not differ by group. Serum was collected at 3.2 h (range 1.9-4.8 h) and 16.3 h (range 13.8-19.1 h) after ingestion of doxycycline in Groups 1 and 2, respectively. Median serum doxycycline levels (milligrams per liter) were 2.7 and 1.8 for Groups 1 and 2, respectively (p=.04). Emesis was experienced by 50% and 15% of women in Groups 1 and 2, respectively (p=.04). Nausea ratings were worse after doxycycline in the morning compared to doxycycline with dinner and compared to placebo at either time (all p<.01). Emesis following doxycycline consumption was not associated with lower doxycycline levels (p>.2).
  
  
  CONCLUSIONS
  When given with food on the night prior to D&E, doxycycline results in less emesis and nausea, but results in lower serum levels at the time of D&E.
authors.affiliation: Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, and Magee-Women's Research Institute, Pittsburgh, PA 15213, USA. mreeves@upmc.edu
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Reeves
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Lohr
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Hayes
authors.forename: Bryna J
authors.initials: BJ
authors.lastname: Harwood
authors.forename: Mitchell D
authors.initials: MD
authors.lastname: Creinin
mesh_terms: D000028:Abortion, Induced / Q000379:methods*; D000284:Administration, Oral; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood* / Q000493:pharmacokinetics; D019072:Antibiotic Prophylaxis / Q000379:methods*; D004311:Double-Blind Method; D004318:Doxycycline / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood* / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D016014:Linear Models; D013997:Time Factors; D014839:Vomiting / Q000139:chemically induced; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline