Medications for Growth Disorders : Part 3

by Food and Drug Administration (FDA)

(Page 3 of 3)

If puberty is being prompted by tumors, radiation treatment or surgical removal of such tumors may be recommended. But often such removal — especially of brain tumors — is not feasible. Moreover, even when surgery is performed, it may not successfully stop sexual development.

Consequently, most doctors prefer to treat children with precocious puberty with drugs that restore the normal hormonal balance in the body. The two newly approved drugs Supprelin and Synarel can stop the accelerated growth and stem or sometimes reverse sexual development in children with true precocious puberty. Supprelin injections can be given at home by a parent. Synarel is given via a nose spray.

These drugs mimic LHRH. Daily doses apparently stem the pituitary gland's responsiveness to the natural hormone. The child's own secretion of LHRH, consequently, no longer triggers sex hormone production. Within weeks of beginning treatment, menstruation and ovulation, or sperm production, usually stop. After several months, many girls' developed breasts shrink and their pubic hair may fall out. The penis and testicles usually shrink back to normal size in boys, and pubic and facial hair often disappear.

The most frequent side effects of these drug therapies are light vaginal bleeding within the first month of treatment in girls, and in both sexes, redness, swelling, and itching at the injection site for Supprelin. Therapy is stopped when a child reaches the appropriate age for the onset of puberty.

Psychological Boosts Needed, Too

Most children on the fringes of what's considered "normal" for growth and development need to be reassured that their unique way of growing up is worthwhile, according to pediatric endocrinologist Leona Cuttler, M.D., of Case Western Reserve University in Cleveland.

"The need to be like everybody else is so strong in children," she says. "It's important to emphasize to them the wide range of what's considered normal for height and development."

In her clinic, she adds, social workers and psychologists assess and help improve, if necessary, the psychological well-being of children with short stature or delayed or precocious puberty. How well these children adjust to their height and development enters into her decision on whether to treat them.

As FDA's Malozowski points out, "the more time you spend with a patient, the less medicine you have to use."

Late Bloomers

Children with delayed puberty are exceptionally short for their age, and have no need for the bras or shavers that are standard equipment for their adolescent peers.

Girls are considered delayed if they don't show any signs of puberty by age 12 or 13, boys by age 14 or 15. At the age when most children experience a pubertal growth spurt, delayed children continue growing at the same slower rate, making them short for their age. Once late bloomers complete puberty, however, their height catches up to that of their peers. About 1 out of every 100 children has delayed puberty.

A red flag for such late bloomers is x-ray evidence that bone maturation lags behind what is expected for the child's age. The degree of bone maturation is appropriate for the child's height, however. Rarely, puberty is delayed or never occurs because of a central nervous system disorder such as hypopituitarism, or because of abnormalities in the sex chromosomes. Chronic illness, malnutrition, or emotional stress can also delay puberty. But usually doctors are unable to detect a cause for delayed puberty. Children with delayed puberty often have a parent who was a late bloomer, and the condition is neither a physical abnormality nor a sign of disease, but nevertheless can have social and psychological ramifications.

Adolescents with delayed puberty, like children with precocious puberty, are often teased or sometimes even ostracized by their peers. A major source of anxiety for these children, especially boys, is short stature.

In several studies, an experimental drug known as oxandrolone — a synthetic compound similar to the male hormone testosterone — boosted growth rates of boys with delayed puberty. Given daily in low doses by mouth, oxandrolone doesn't usually prompt puberty, studies suggest, nor does it appear to affect final height, although more studies are needed to firmly establish this. It mainly accelerates children's growth so their heights reach those of their peers already undergoing puberty. Several studies found no short-term side effects tied to oxandrolone therapy.

To boost sexual development, doctors may treat late bloomers with sex hormones, though this use is experimental. Testosterone given monthly by injection to boys usually induces sprouting of pubic and facial hair and the enlargement of the penis. The therapy sometimes makes boys more aggressive and may have other side effects. Girls given female hormones — estrogen or estrogen and progestin combinations — often develop breasts and start to menstruate. Potential side effects of this therapy include nausea, fluid retention, depression, and circulatory disorders.

There is concern that sex hormone treatments might limit final height, as they do in precocious puberty. But recent research suggests that low doses of these hormones do not rob late bloomers of inches.

Oxandrolone, testosterone, estrogen, and progestin are usually only given for about six months to a year to children with delayed puberty. At this point, studies show, most children have entered puberty and no longer need the drugs.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.