The effect of oxandrolone and the timing of pubertal induction on final height in girls with Turner’s syndrome receiving a standard dose of growth hormone, has been evaluated in a RCT conducted at 36 paediatric endocrinology departments in UK hospitals.

The study involved girls aged 7-13 years at recruitment on treatment with recombinant growth hormone therapy (10 mg/m2/week), who were randomised to oxandrolone (0.05 mg/kg/day, maximum 2.5 mg/day) or placebo from age 9. Those with evidence of ovarian failure at 12 years were further randomised to oral ethinylestradiol (year 1, 2 mcg daily; year 2, 4 mcg daily; year 3, 4 months each of 6, 8, and 10 mcg daily) or placebo. Those who received placebo and those recruited after the age of 12.25 years started ethinylestradiol at age 14. The main outcome measure was final height.

The following findings were reported:

• Of 106 girls recruited, 14 withdrew and 82/92 reached final height.

• Both oxandrolone and late pubertal induction increased final height: by 4.6cm (p=0.001, n=82) for oxandrolone and 3.8cm (p=0.05, n=48) for late pubertal induction with ethinylestradiol.

• In the 48 children randomised twice, the effects on final height (compared with placebo and early induction of puberty) of oxandrolone alone, late induction alone, and oxandrolone plus late induction were similar, averaging 7.1cm (p<0.001).

• No cases of virilisation were reported.

The researchers conclude from these findings that oxandrolone had a positive effect on final height in girls with Turner’s syndrome treated with growth hormone, as did late pubertal induction with ethinylestradiol at age 14 years, though as these effects were not additive, there would be no benefit from using both. They therefore suggest that oxandrolone could, be offered as an alternative to late pubertal induction for increasing final height in Turner’s syndrome.