December 26, 2005

Hormone-blocking implant halts too-early puberty

By Will Boggs, MD

NEW YORK (Reuters Health) - Sometimes, when hormones get
out of kilter, young girls can enter puberty at too early an
age -- before they're even 7 or 8 years old and before they're
ready to stop growing and begin sexual maturation. Now, an
Israeli team has come up with a convenient way to stop the

They report that an implant containing histrelin, a potent
inhibitor of gonadotropin-releasing hormone, is effective in
treating central precocious puberty, as the condition is

"The histrelin implant consistently suppresses clinical and
laboratory parameters of puberty for one year and is a
promising new technique for treating central precocious puberty
without the pain and inconvenience of monthly injections,"
write Dr. Irving M. Spitz from Shaare Zedek Medical Centre,
Jerusalem, and colleagues in the medical journal of Pediatrics.

Spitz's team investigated whether a histrelin implant would
suppress gonadotropin and estradiol, hormones that bring on
puberty and menstruation, in 11 girls with central precocious
puberty for 12 months and compared the suppression to standard

There was no menstrual bleeding during the implant
treatment, the authors report, and mean breast development
regressed somewhat during treatment.

The acceleration in bone maturation that would signal an
end to growth in height decreased during treatment, as did
growth velocity, the report indicates.

Puberty hormones remained suppressed at nine months after
implant insertion in all 11 girls, and up to 15 months in the
six girls who returned late to have the implant removed, the
researchers note.

All the girls reported less pain and discomfort and less
interference with school activity and work with the implant
than with standard monthly injections, the investigators

"A multicenter clinical trial is currently underway in the
United States," Dr. Spitz told Reuters Health. "We are
continuing to follow our Israeli patients, and we plan to study
(normal hormone) recovery following implant removal at the
completion of the course of treatment."

SOURCE: Pediatrics, December 2005.