Medical treatments for uterine fibroids

Contents

• Introduction
• Existing medical treatments for fibroids
• Promising new medical treatment for fibroids

Introduction

Uterine fibroids are common, and are found in up to 70–80% of women by the time they reach the menopause. Their prevalence increases with age, from approximately 20% of women at the age of 20 years to 35–60% at the age of 35 years. Fortunately, the majority of the fibroids are harmless and only half of them are considered ‘significant’. Due to the high prevalence of fibroids a large number of treatment options are available. These include surgical removal of fibroids (myomectomy), uterine artery embolisation (an angiography procedure, which blocks the blood supply to the fibroids causing them to shrink), high frequency ultrasound treatment and hysterectomy.

Existing medical treatments for fibroids

Medical (drug) treatments for fibroids have traditionally been of limited value due to their temporary effects and unwanted side effects. Derivatives of the progesterone hormone (called progestins) are sometimes used to control the bleeding symptoms that some fibroids may cause, but they do not reduce the size of fibroids. These hormones can be taken as tablets or used in the form of an intrauterine contraceptive system called Mirena IUS. Mirena is particularly useful when the cavity of the uterus is not very large or distorted by the presence of fibroids. For more information on the treatment of irregular or heavy periods please click here.

Drugs called GnRHa’s (Gonadotropin releasing hormone analogues – drugs such as Gonapeptyl, Prostap, Zoladex, etc.) switch off the stimulation of the ovaries by the pituitary gland, which is an area under the brain. Lack of this stimulation sends the ovaries “to sleep” and creates a condition similar to “temporary menopause”. This causes very low oestrogen levels in the circulation and the lack of oestrogen results in shrinkage of the fibroids and cessation of periods. However, the low oestrogen levels also cause side effects similar to the symptoms of menopause such as hot flushes, night sweats and vaginal dryness. It also causes loss of bone density (osteoporosis) and, for this reason these drugs can only be used for a limited period of 3–6 months. When they are discontinued the fibroids usually grow back to their original size and the periods return. GnRHa’s are therefore not suitable for the long-term treatment of fibroids but are usually used to stop the heavy periods and shrink the fibroids before their surgical removal. This treatment is beneficial as it allows the correction of any low blood count (anaemia) before surgery and reduces blood loss at surgery. These drugs are usually given as monthly or three-monthly injections and occasionally as sprays into the nostrils.

Promising new medical treatment for fibroids

A promising new medical treatment for fibroids has recently become available that uses the drug ulipristal acetate (Esmya), which belongs to a group of drugs called selective progesterone receptor modulators (SPRMs). These drugs usually block the progesterone receptors in a number of organs and tissue. The effect on fibroids of this drug is a significant reduction in the size. In addition, they reduce period bleeding and may stop them altogether in a matter of 7–10 days. This not only puts an end to the troublesome periods but also corrects anaemia. These drugs do not lower oestrogen levels and therefore do not cause menopausal symptoms. They are in tablet form and are taken once a day by mouth, without the need for injections.

These drugs are currently licensed to be used to shrink fibroids before operations for a period of three months. When they are discontinued after three months the periods return quickly, but the size of the fibroids take longer to return to their original size, compared to the GnRHa injections. The long-term usage has not been tested as yet and, as a result, they should not be used for longer than three months. Further clinical studies are currently under way to test the benefits and risks of their long term use.

In conclusion, ulipristal acetate appears to be a very good alternative to GnRHa injections as it does not cause major side effects and can be taken by mouth, whilst it has similar efficacy in reducing the size of fibroids. Furthermore, it resolves troublesome bleeding quicker than GnRHa injections. Once long-term studies are completed it may provide a real alternative to surgery (myomectomy or hysterectomy) and uterine artery embolisation.

For further information on the author of this article, Consultant Gynaecologist, Mr Ertan Saridogan, please click here.