title: Effect of obesity on recombinant follicle-stimulating hormone absorption: subcutaneous versus intramuscular administration.
abstract: OBJECTIVE
  To determine whether recombinant follicle-stimulating hormone (rFSH) should be administered intramuscularly (i.m.) or subcutaneously (s.c.) to obese women.
  
  
  METHODS
  Randomized, single-center, two-way crossover study.
  
  
  METHODS
  Academic clinical research center.
  
  
  METHODS
  Nineteen healthy women of reproductive age with body mass indices of 19.9 kg/m(2)-42.8 kg/m(2).
  
  
  METHODS
  Leuprolide acetate 3.75 mg i.m. to achieve pituitary down-regulation as determined by serum E(2) levels. Subjects were then given a single dose of 300 IU rFSH either i.m. or s.c.. Multiple blood sampling was performed over the next two weeks, and after retreatment with leuprolide, a second 300 IU rFSH dose was given via the other administration route.
  
  
  METHODS
  Serum samples were analyzed in duplicate for follicle-stimulating hormone (FSH) using a standard radioimmunoassay in a single run. Maximum concentrations (C(max)), times to C(max) (T(max)), and extent of absorption (area under curve [AUC]) with i.m. vs. s.c. administration were compared using paired analysis.
  
  
  RESULTS
  Maximal concentrations were achieved within 24 hours with both s.c. and i.m. routes. No significant differences were found in C(max), T(max), or AUC with s.c. vs. i.m. administration. A decline of AUC occurred among subjects of higher body mass index (BMI) with rFSH given either s.c. or i.m.. Subcutaneous administration achieved AUCs comparable to i.m. administration in both normal-weight and obese subjects.
  
  
  CONCLUSIONS
  Our data indicate that the s.c. administration of rFSH is appropriate for women regardless of body mass.
authors.affiliation: Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama 35249-7333, USA. msteinkampf@uabmc.edu
authors.forename: Michael P
authors.initials: MP
authors.lastname: Steinkampf
authors.forename: Karen R
authors.initials: KR
authors.lastname: Hammond
authors.forename: John E
authors.initials: JE
authors.lastname: Nichols
authors.forename: Scott H
authors.initials: SH
authors.lastname: Slayden
mesh_terms: D000328:Adult; D019540:Area Under Curve; D015992:Body Mass Index; D018592:Cross-Over Studies; D005260:Female; D005300:Fertility Agents, Female / Q000494:pharmacology; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D007273:Injections, Intramuscular; D007279:Injections, Subcutaneous; D016729:Leuprolide / Q000494:pharmacology; D009765:Obesity / Q000378:metabolism*; D010062:Ovulation Induction / Q000379:methods*
chemical_list: D005300:Fertility Agents, Female; D005640:Follicle Stimulating Hormone; D016729:Leuprolide