From the Guidelines
Add-back therapy is a treatment strategy that involves supplementing with small doses of estrogen and/or progestin to mitigate the side effects of GnRH agonists while maintaining their therapeutic benefits in the management of endometriosis. This approach is used to minimize the adverse effects of GnRH agonists, such as bone loss and menopausal symptoms like hot flashes and vaginal dryness, allowing for longer-term use of these medications in managing endometriosis symptoms 1. The therapy typically involves the use of low-dose sex-steroid hormone therapy, such as norethindrone acetate or a combination of conjugated equine estrogens and medroxyprogesterone acetate, which helps to create a hypoestrogenic/hypoprogestrogenic state that reduces uterine and fibroid size while minimizing side effects 1.
Some key points to consider when using add-back therapy include:
- The therapy is usually started at the same time as the GnRH agonist and continued for the duration of the treatment, which is often 6-12 months 1.
- The goal of add-back therapy is to provide a low level of hormones that minimizes side effects while maintaining the therapeutic benefits of GnRH agonists 1.
- Patients should be monitored regularly during treatment to ensure the therapy's effectiveness and to adjust dosages if needed 1.
- Add-back therapy can be used in combination with other treatments, such as GnRH agonists, to manage endometriosis symptoms and improve quality of life 1.
Overall, add-back therapy is a valuable treatment strategy for managing endometriosis symptoms and improving quality of life, and its use should be considered in patients who are being treated with GnRH agonists 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Definition of Add-Back Therapy
Add-back therapy, also known as hormone replacement therapy, is a treatment approach used in conjunction with gonadotropin-releasing hormone (GnRH) agonists to alleviate hypoestrogenic side effects, such as bone loss and vasomotor symptoms, while maintaining the therapeutic effects of GnRH agonists 2, 3, 4, 5, 6.
Purpose of Add-Back Therapy
The primary purpose of add-back therapy is to:
- Prevent bone loss and reduce the risk of osteoporosis
- Alleviate vasomotor symptoms, such as hot flashes and night sweats
- Improve quality of life for patients undergoing GnRH agonist therapy
- Allow for longer treatment durations with GnRH agonists while minimizing side effects 2, 3, 4, 5, 6.
Types of Add-Back Therapy
Different types of add-back therapy have been studied, including:
- Low-dose hormone replacement therapy (HRT) with estrogen and progestin
- Norethindrone acetate (NA) with or without conjugated estrogens (CEE)
- Estradiol valerate and medroxyprogesterone acetate
- Tibolone, a gonadomimetic agent 2, 3, 4, 5, 6.
Key Findings
Key findings from studies on add-back therapy include:
- Add-back therapy can effectively alleviate hypoestrogenic side effects and improve quality of life for patients with endometriosis 2, 3, 5
- Low-dose add-back therapy may be as effective as regular-dose therapy in preventing side effects while minimizing the risk of endometriosis recurrence 3
- The choice of add-back therapy may depend on individual patient needs and the specific indication for GnRH agonist therapy 4, 5, 6.