Decreasing the dose of Lupron (leuprolide) to half shows good clinical effectiveness in women with endometriosis stage 3 and 4 while preventing significant bone loss, a small study suggests.

Titled “Curative effect of 1.88-mg and 3.75-mg gonadotrophin-releasing hormone agonist on stage III–IV endometriosis: Randomized controlled study,” the study was published in The Journal of Obstetrics and Gynaecology Research.

Lupron, one of the most widely used gonadotrophin-releasing hormone (GnRH) agonists, has been used as therapy for endometriosis. But its use has been limited because this treatment is associated with significant side effects, such as a reduction in bone mineral density (BMD), hot flashes, and sexual complaints, such as loss of libido and vaginal dryness.

GnRH agonists are drugs that target and activate the gonadotrophin-releasing hormone receptor, which regulates the release of important hormones that control several processes, including development, growth, and reproductive processes.

In a previous report, authors suggested that low-dose gonadotrophin-releasing hormone agonist therapy (draw-back therapy) could prevent these side effects.

Now, a team of researchers set out to evaluate the therapeutic effects of Lupron (leuprolide) in two different doses — 1.88 mg and 3.75 mg (the clinical dose) — for treating endometriosis patients who had undergone laparoscopic surgery.

The study enrolled 50 women  with stage 3 and 4 endometriosis who were randomly assigned to two groups — the full-dose group (treated with GnRH agonist at 3.75 mg) and the half-dose group (GnRHa at 1.88 mg). To determine the drug’s efficacy and its adverse effects, researchers measured several parameters, including the levels of sex hormones, symptoms of estrogen deficiency and lumbar vertebrae bone density.

The half-dose group received the first two injections at 3.75 mg, followed by injections at 1.88 mg up to and including the sixth injection. The control group (full-dose group) was treated with 3.75 mg GnRHa for six injections.

While bone density was reduced in both groups, the degree of bone loss was higher in the full-dose group (5.6%) when compared to that of the half-dose group (1.2%). After eight weeks of treatment, both groups had symptoms of perimenopause. However, there was a pronounced decrease in the Kupperman score (used to determine the severity of menopausal symptoms) at 20 weeks after treatment in the half-dose group — at eight weeks the score 12.8 and at 20 weeks it was 6.4. The reverse was detected in the full-dose group, with scores increasing from 14 at week eight to 19.6 at week 20, respectively.

“After treatment, follicle-stimulating hormone and luteinizing hormone both decreased in both groups, but there was no difference between the two groups,” the researchers added.

Overall, these findings support the use of Lupron at 1.88 mg as therapy for women with stage 3 to 4 endometriosis after laparoscopic surgery, as it reduced menopausal symptoms, significantly improved bone loss, and achieved a good clinical effect.