title: Comparative pharmacokinetics and pharmacodynamics after subcutaneous and intramuscular administration of medroxyprogesterone acetate (25 mg) and estradiol cypionate (5 mg).
abstract: BACKGROUND
  The efficacy of contraceptives is affected by its route and ease of administration. Herein, both pharmacokinetics and pharmacodynamics of the once-a-month combined injectable contraceptive medroxyprogesterone acetate (MPA) plus estradiol cypionate (E(2)-Cyp) were compared after intramuscular (IM) or subcutaneous (SC) injection in women of reproductive age.
  
  
  METHODS
  Thirty women were randomly assigned to the SC (n=15) or IM (n=15) route of MPA 25 mg+E(2)-Cyp 5 mg administration. Serum samples were obtained daily for 7 days and then three times a week for 40 days in order to quantify E(2), progesterone and MPA. In addition, three ultrasounds were performed on each subject to determine follicular development, and a daily record of the bleeding pattern and side effects was maintained.
  
  
  RESULTS
  A comparative analysis showed that the main pharmacokinetic (peak serum concentration, peak serum time, area under the serum concentration vs. time curve, absorption half-life and elimination half-life) and pharmacodynamic parameters, such as follicular development and ovulation, were similar in the SC vs. IM groups. Complete suppression in ovarian function was present in all women. The bleeding patterns and side effects were similar in both groups.
  
  
  CONCLUSIONS
  The results presented herein demonstrate that the injection of 25 mg of MPA plus 5 mg of E(2)-Cyp has similar efficacy and safety with either the SC or IM route of administration. The SC option can be considered a viable self-administered contraceptive option that might increase women's compliance to contraceptive use.
authors.affiliation: Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Mexico City, 11000, Mexico. alfsierra08@yahoo.com
authors.forename: José Alfredo
authors.initials: JA
authors.lastname: Sierra-Ramírez
authors.forename: Roger
authors.initials: R
authors.lastname: Lara-Ricalde
authors.forename: Miguel
authors.initials: M
authors.lastname: Lujan
authors.forename: Norma
authors.initials: N
authors.lastname: Velázquez-Ramírez
authors.forename: Marycarmen
authors.initials: M
authors.lastname: Godínez-Victoria
authors.forename: Ivonne Araceli
authors.initials: IA
authors.lastname: Hernádez-Munguía
authors.forename: Agustin
authors.initials: A
authors.lastname: Padilla
authors.forename: Josué
authors.initials: J
authors.lastname: Garza-Flores
mesh_terms: D000042:Absorption; D000293:Adolescent; D000328:Adult; D003271:Contraceptive Agents, Female / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology*; D003692:Delayed-Action Preparations / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology; D004338:Drug Combinations; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology; D005260:Female; D006207:Half-Life; D006801:Humans; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage* / Q000009:adverse effects / Q000097:blood / Q000494:pharmacology*; D008597:Menstrual Cycle / Q000097:blood / Q000187:drug effects; D009866:Oogenesis / Q000187:drug effects; D006080:Ovarian Follicle / Q000000981:diagnostic imaging; D034445:Ovulation Inhibition / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D014463:Ultrasonography; D055815:Young Adult
chemical_list: D003271:Contraceptive Agents, Female; D003692:Delayed-Action Preparations; D004338:Drug Combinations; D011374:Progesterone; D004958:Estradiol; C007630:estradiol 17 beta-cypionate; D017258:Medroxyprogesterone Acetate