Medical Management Of Uterine Fibroids: GnRH Agonists, SPRMs, and Beyond

Introduction

Did you know that around 2 in 3 women will develop at least 1 fibroid in their lifetime? Around a third of these women will also experience symptoms. From pelvic pain to heavy periods, fatigue and bloating, fibroid symptoms can have a huge impact on daily life. The right medical management can help many people find relief through non-surgical treatments tailored to their needs.¹ 

Fibroids are benign growths that develop in or around the uterus, also known as the womb. In many people, these cause no symptoms or issues and may either never be picked up, or be discovered incidentally on a scan or examination. In those who do experience fibroid symptoms, however, there can be a huge impact on physical and emotional well-being. The good news is that there are different medical treatments available, ranging from hormonal treatments to other targeted medications to control bleeding and even shrink fibroids.  

This article will explore medical options for the treatment of fibroids, including Gonadotropin Receptor Hormone agonists (GnRH agonists), Selective Progesterone Receptor Modulators (SPRMs) and other hormonal and non-hormonal treatments.²

What are uterine fibroids?

Fibroids, also referred to as leiomyomas, are benign growths from the uterus that are made up of smooth muscle and connective tissue. What causes them is not completely understood, but some key risk factors for the development of fibroids include advancing age, black and Asian ethnicity, obesity, diabetes, hypertension and family history. Oestrogen, progesterone, which are important reproductive hormones, and local growth factors are involved in promoting the growth of uterine fibroids. The symptoms can vary depending on the size, location and position of the fibroids.²

Symptoms can include:

• Heavy menstrual bleeding (menorrhagia)
• Anaemia secondary to increased menstrual blood loss, causing fatigue
• Pelvic pain or pressure
• Bowel symptoms, e.g. constipation
• Bladder symptoms, e.g. frequent urination
• Sexual dysfunction, e.g. pain/discomfort during sex
• Abdominal pain
• Bloating
• Lower back pain

These symptoms vary from person to person, and they can have a significant impact on quality of life. This is why it is so important to be aware of options for treatment, including medical management.^2,3

When is medical management the right choice?

When deciding on management of fibroids, it is important to consider individual circumstances, including symptoms, size and position of fibroids, family and retaining the uterus. For example, if fibroids are causing symptoms but not severely impacting well-being, medical management may be the best option. Additionally, medical treatments offer a non-invasive approach which can delay the need for surgery or even avoid the need for it completely. Planning for pregnancy is also an important consideration as certain surgical options may delay time to conception, so medical management may be most appropriate in some cases. In menopause, fibroids can naturally shrink on their own, so in cases where women are approaching this, medical management may be the best option for symptom control as a bridge until menopause.⁴ 

Medical management may not be the solution for everyone, but for many women, it is an effective step towards taking back control. Medical treatments have the potential to significantly improve symptoms and shrink fibroids, and an informed decision should be made about whether this would be right for you.³

GnRH agonists

Gonadotropin-releasing hormone agonists (GnRH agonists) are medications that cause the ovaries to stop making oestrogen and progesterone, effectively temporarily switching them off. This results in periods stopping in most women and shrinking fibroids. These medications can be used preoperatively, short-term, to reduce fibroid size before surgery. They can also be used to allow for increased preoperative haemoglobin levels and potentially a minimally invasive surgical approach. GnRH agonists are, however, effectively medically inducing a menopause-like state, and therefore come with side effects. Side effects include hot flushes, mood swings, vaginal dryness, reduced libido, sleep disturbance and bone loss in long term use. It is important to understand that GnRH agonists are a temporary treatment, and it is found that after stopping this treatment, fibroids grow back to their original size.^2,4

Selective progesterone receptor modulators (SPRMs)

Selective progesterone receptor modulators (SPRMs), for example, ulipristal acetate, are medications that block the effects of progesterone, causing increased cell death and reduced tissue growth. This effectively shrinks fibroids and causes thinning of the endometrium, and therefore reduced menstrual bleeding. SRPMs can be used periodically for up to four courses to treat moderate to severe fibroid symptoms before menopause. They also have fewer menopausal side effects than GnRH agonists. On these treatments, liver function must be closely monitored as there can be rare but serious side effects on the liver.^5,6

Other medical management options

There are various other medical treatment options available for the management of fibroids. These treatments are mainly aimed at controlling fibroid symptoms and can even shrink fibroids. Choosing the right treatment depends on symptoms, medical history and personal preferences. They can be categorised as hormonal and non-hormonal.

Hormonal treatments

Combined oral contraceptive

Combined oral contraceptives contain both oestrogen and progesterone. These hormones work together to prevent pregnancy through multiple mechanisms. One of these mechanisms is altering the lining of the womb, keeping it thin so it is less likely that a fertilised egg will be able to implant. The lining of the womb being thin also means less shedding during menstruation and therefore less bleeding during periods. This is very useful for controlling the heavy periods caused by fibroids.²

Progesterone-only treatments

There are also hormonal options containing progesterone only, including the Levonorgestrel IUD, also known as the Mirena coil. There is also the option of the progesterone-only pill. There are also progesterone-only injections, however, these are less useful, as they tend to cause irregular bleeding.²

Progesterone acts on the lining of the womb to repress the endometrial growth driven by oestrogen. This effectively reduces blood loss during periods. The Mirena coil acts locally on the lining of the womb, so it has minimal side effects. It is effective in improving heavy periods and can cause periods to stop in many women.^2,3

Non-hormonal treatments

Tranexamic acid

Tranexamic acid is a medication that promotes the clotting of blood. This is useful in fibroid management as it can be taken during periods to reduce the bleeding.³

NSAIDs

Non-steroidal anti-inflammatory drugs are medications that reduce the production of proinflammatory substances. This helps relieve the pain and cramping experienced during periods.³

Iron supplements (for anaemia)

Increased blood loss during periods can lead to anaemia in many women. Anaemia can cause a number of symptoms including fatigue, dizziness, weakness/lightheadedness, palpitations, breathlessness and headaches. Iron supplementation may be required to treat this.³

Comparing treatments: What to consider

Comparing Treatments: What Matters Most

Below is a summary of some of the medical options discussed in this article, comparing key characteristics

FAQs

Can medical treatments get rid of my fibroids completely?

Medical treatments are mainly aimed at helping to control the symptoms of fibroids. Some of the treatments described above can shrink fibroids, but they are not curative.

Are there natural ways I can treat my fibroids?

There are no natural/herbal remedies with evidence to show that they can shrink fibroids. There are lifestyle factors that can help with symptoms, including maintaining a healthy weight, balanced diet, exercise and managing stress.² 

Can fibroids get better without any treatment?

Studies show that after menopause, with the naturally reduced levels of the hormones oestrogen and progesterone, fibroids often shrink.² 

Fibroids that are small and not causing any symptoms can also shrink spontaneously or stay the same and never require treatment.

Can I start these treatments if I'm trying to get pregnant?

In terms of medical treatments available, hormonal contraceptives and GnRH agonists are not suitable to start for women trying to get pregnant, as they inhibit ovulation. There are medications for managing fibroid symptoms that will not affect pregnancy plans, such as NSAIDs and tranexamic acid. Make sure to discuss planning for pregnancy with your doctor when discussing fibroid treatment options.³

Summary and takeaway points

• There are medical treatment options for fibroids that can significantly improve symptoms without having to undergo an invasive procedure that could be right for you
• These treatments are not for everyone, but it is important that you have all the relevant information before making decisions when it comes to your health
• Your management plan should take into consideration your preferences, your symptoms and personal circumstances
• Talk to your doctor about your options, take your time and ask questions so you can make an informed decision