Effect of obesity on recombinant follicle-stimulating hormone absorption: subcutaneous versus intramuscular administration.
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.
Steinkampf
Michael P
MP
Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, Alabama 35249-7333, USA. msteinkampf@uabmc.edu
Hammond
Karen R
KR
Nichols
John E
JE
Slayden
Scott H
SH
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*
D005300:Fertility Agents, Female; D005640:Follicle Stimulating Hormone; D016729:Leuprolide