Treatment of endometriosis with a decreasing dosage of a gonadotropin-releasing hormone agonist (nafarelin): a pilot study with low-dose agonist therapy ("draw-back" therapy).
OBJECTIVE
To evaluate the efficacy of half-dose GnRH agonist therapy for endometriosis.


METHODS
Prospective, longitudinal pilot study.


METHODS
Osaka University Hospital.


METHODS
Patients with symptomatic endometriosis.


METHODS
Fifteen patients were randomized to receive either full-dose nafarelin treatment (200 microgram b.i.d.) for 24 weeks (n = 7) or full-dose nafarelin treatment for 4 weeks followed by half-dose nafarelin treatment (200 microgram daily) for 20 weeks (n = 8).


METHODS
Clinical symptoms and the results of physical examinations. Serum E(2) and carcinoma antigen 125 (CA125) levels, lipid profiles, and urinary levels of the N-telopeptide of type I collagen. Bone mineral density of the lumbar spine.


RESULTS
Subjective and objective manifestations of endometriosis were decreased to a similar extent in both study groups. Adverse effects were markedly reduced with half-dose administration. In the half-dose group, the mean serum E(2) level was significantly suppressed by 4 weeks of treatment with full-dose nafarelin and remained at approximately 30 pg/mL with half-dose nafarelin. Loss of bone mineral density was significantly less with half-dose treatment.


CONCLUSIONS
Half-dose administration of nafarelin after pituitary down-regulation with full-dose nafarelin ("draw-back" therapy) is a new protocol for the treatment of endometriosis that is effective and associated with fewer adverse effects.
Tahara
M
M
Department of Obstetrics and Gynecology, Osaka University Faculty of Medicine, Osaka, Japan.
Matsuoka
T
T
Yokoi
T
T
Tasaka
K
K
Kurachi
H
H
Murata
Y
Y
D000281:Administration, Intranasal; D015519:Bone Density / Q000187:drug effects; D018394:CA-125 Antigen / Q000097:blood / Q000187:drug effects; D003094:Collagen / Q000187:drug effects / Q000652:urine; D004244:Dizziness / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004715:Endometriosis / Q000188:drug therapy*; D004958:Estradiol / Q000097:blood; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000819:agonists; D006728:Hormones / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000187:drug effects; D008597:Menstrual Cycle / Q000187:drug effects; D017274:Nafarelin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D010865:Pilot Projects; D011446:Prospective Studies
D018394:CA-125 Antigen; D006728:Hormones; D017274:Nafarelin; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D003094:Collagen