Immediate and delayed add-back hormonal replacement therapy during ultra long GnRH agonist treatment of chronic cyclical pelvic pain

Abstract

Objective: To assess the safety and efficacy of long-term use of long-acting GnRH agonist in women with chronic cyclical pelvic pain using immediate versus delayed add-back hormonal replacement therapy (HRT).

Design: A prospective randomised trial.

Setting: Reproductive and Developmental Medicine, Academic Unit, University Teaching Hospital and NHS Hospitals.

Population: Thirty-eight premenopausal women with chronic cyclical pelvic pain were recruited.

Methods: Women were given Zoladex 10.8 mg over 18 months and randomised to receive HRT (tibolone 2.5 mg) either immediately or after 6 months. Follow up was 12-month post-treatment.

Main outcome measures: Bone mineral density at 6 months, the end of treatment (18 months), and 12 months later, pain and quality of life.

Results: Women treated with immediate HRT add-back showed less bone mineral density loss at 6 months and less vasomotor symptoms compared with those who had delayed HRT add-back treatment. Long-term follow up showed both groups experienced equivalent bone mineral density loss. Pain and health-related quality-of-life assessment showed improvement in both groups but there was evidence of a return to baseline levels after ending treatment.

Conclusion: Long-term use of GnRH agonist plus immediate add-back HRT is a safe and acceptable approach to intractable cyclical pelvic pain. Given the delay in reactivation of the hypothalamo-pituitary-ovarian axis after long-term suppression, an intermittent dose regime with GnRH agonist might warrant investigation.