Gender Centre » Resources » Kits & Fact Sheets » Hormone Implant Information

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Your doctor has advised you to have hormone replacement therapy by the implant technique. The purpose of this brochure is to give you information about the nature of implants, their action, their benefits, possible side effects, and methods of implantation.

Hormone replacement therapy, particularly at the time of the menopause, has been available for decades. Oestrogen replacement is usually given by mouth which though effective, does not always keep the level of oestrogen in the blood within a desirable range. There is a growing trend towards the administration of hormones by non-oral routes, such as by implantation.

Although they have been available for many years, it is only in recent times there has been increased attention to the use of implants for hormone replacement therapy.

This brochure will consider the two commonly used implants, oestradiol (oestrogen) and testosterone implants.

Hormone implants are made by fusing pure crystals of the hormone in a mould. They are approximately the size of a grain of wheat.

The hormone implant is placed in the fat under the skin of the abdominal wall or the upper leg. From here the hormone is slowly absorbed into the bloodstream. The most important factors affecting the rate of absorption are the surface area of the implant and an adequate blood supply to the implant (wherever it is situated).

Sometimes fibrous tissue may develop around the implant and slow its absorption; if this occurs the implant needs to be replaced. As heat may increase the absorption rate of the hormone, hot water bottles should not be placed over the implantation site.

You may expect your oestrogen (or testosterone) implant, depending on its dose, to last many months.

Specific Information

Oestradiol implants, when inserted subcutaneously (under the skin), provide a very slow release of the natural oestrogen, oestradiol. In this way they provide a more steady release of oestrogen than oral preparations.

They have the added advantage of being in place for a long period of time and of not requiring more frequent administration of medication.

The hormone implants are available in 20mg, 50mg and 100mg sizes. Your doctor will advise you about the appropriate dose. The duration of action depends on the dose and rate of absorption and varies between individuals.

If you have not had a hysterectomy, you doctor will advise you to take tablets of the hormone progestogen for the first 10-14 days of each month. This will protect you from the very small chance of developing an abnormality of the lining (endometrium) of the uterus. If you have had a hysterectomy, for whatever reason, progestogen supplementation may not be considered necessary.

The beneficial effects of the oestradiol implant include the alleviation of premenopausal symptoms, the prevention of the onset, or the worsening of osteoporosis, and a reduction in the incidence of cardiovascular disease in the future.

Oestrogen replacement therapy (including oestradiol implants) should not be used if the patient has any of the following conditions:

• Pregnancy;
• Some cardiovascular disorders;
• Severe hypertension;
• Active liver disease;
• Known or suspected oestrogen dependant tumours;
• Undiagnosed vaginal bleeding; or
• A rare blood disorder called porphyria.

Certain pregnancy associated conditions you may have suffered including severe liver disease or itch may preclude the use of oestrogen as hormone replacement therapy in the menopause.

Testosterone is a hormone which is responsible for the characteristics of the male. However, it is responsible for libido (sex drive) in both sexes.

It is a sex hormone that is produced in the process of oestrogen production in a normal premenopausal woman. In women, testosterone is used predominantly for those who have an absent libido following either a surgical or natural menopause.

It should be pointed out that women who use this preparation do not experience masculinisation effects providing they are having concurrent oestrogen treatment.

The presentation of the testosterone implant is similar to that of the oestrogen implant and its insertion methods are the same.

Should masculinisation in any form take place, for example, excessive hair growth or lowering of the voice, in particular, you should notify your doctor immediately.

You should contact your doctor immediately if:

• Severe worsening of varicose veins occurs;
• You are contemplating elective surgery;
• Unexpected vaginal bleeding occurs;
• Severe breast pain develops;
• Abnormal pigmentation develops particularly around your eyes;
• You experience severe nausea;
• Excess fluid gain occurs; or
• Inflammation develops over the implementation site or suspected expulsion of the implant occurs.

The effectiveness level of this preparation is very high if the precautions mentioned above are observed. The usual method of assessment for replacement of the implant is the return of symptoms. Your doctor may also monitor your blood levels of oestrogen in order to determine the appropriate time for replacement.

There are three methods of inserting hormone implants and these are discussed below:

• At the time of definitive surgical procedure such as hysterectomy, the implant may be left underneath the skin at the completion of the operation;
• The open surgery method: This method involves making a small incision in the skin under local anaesthetic. The skin is cut with a scalpel and forceps used to directly place the implant under the skin. The incision is then closed with a stitch and this is removed 2 days later. The scar fades and is virtually unnoticeable within a month;
• The implant can be placed under the skin using a small instrument about the size of a pencil. The procedure is done in the doctor's surgery. The incision may be closed with either a stitch or an adhesive surgical dressing, which is removed a couple of days later.

This implant information booklet has been prepared for issue to patients where implant therapy has been considered desirable by the physician.

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