Maintenance GAHT prescribing for adult transgender patients

Pathways to starting GAHT vary between DHB's. Most commonly, it is commenced by endocrinology or sexual health, with a gradually increasing number of GPs coming on board to commence hormones under an informed consent model in primary care.

Many secondary care services require a readiness for hormone assessment by a mental health professional before starting hormones. Following this, a thorough consent process outlining permanent and reversible effects and discussion of risks is undertaken.

This section looks at how GPs can safely provide repeat prescriptions for patients who have already been commenced on testosterone based/masculinising gender-affirming hormone therapy (T-GAHT).

There are three routes of testosterone administration used in NZ. Most people choose injections due to the less frequent dosing and more stable hormone levels.

Oral Testosterone: Andriol capsules are not currently funded unless someone is already on them. Due to frequent dosing required for stable levels, and the risk of liver toxicity, these are not as commonly used for GAHT.

Topical Testosterone: Androderm patches 7.5mg daily (skin irritation is common).

Once a person is on standard doses of testosterone, there are not usually many changes to their prescription, however, some people may wish to increase more gradually, and these people may require up-titration of their dose. They require 3-6 monthly blood tests (see below) in the first year and annually thereafter. It is recommended to monitor their BP and weight annually.

You may wish to review your patient to check in with how they are going, in particular:

• Are they happy with the testosterone and the effects they have experienced?
• Are they experiencing any side effects or problems they wish to discuss?
• Do they want to continue taking testosterone?
• Are any other referrals for gender-affirming healthcare required?

Blood tests should be checked 3-6 monthly in the first year and annually thereafter.

Testosterone dose can be adjusted by the GP as needed to ensure suitable levels, as long as the recommended maximum dose is not exceeded.

Low dose testosterone

Some people (such as non-binary patients) prefer to take low dose testosterone. They should be informed that the same permanent effects as someone taking standard doses are likely to occur. People may wish to start on a low dose and increase more slowly, or they may choose to remain on a low dose.

There is little evidence to guide practice, but many experts recommend maintaining testosterone of >5-6 nmol/L to reduce longer-term cardiovascular or bone risks. Testosterone dose can be adjusted as per patient’s wishes, provided adequate testosterone levels for bone health are maintained and that maximum doses are not exceeded.

Vaginal bleeding

Monthly bleeding will stop in most individuals after 3-6 months on testosterone but may continue in around 10%. Progesterone can be used to stop periods, and if contraception is also needed, this could be in the form of a Mirena, Depo-Provera or a combined/progesterone-only oral contraceptive.

For new-onset bleeding, check that testosterone levels are in the normal range, and if so, investigate as per usual guidelines.

Other considerations

• Ensure you have recorded the patient's desired name and pronouns on your PMS.
• Anyone with a cervix requires cervical screening – ensure recalls are not missed.
• If indicated, contraception is needed even if periods have stopped.
• Many trans masculine patients use a binder. This can cause discomfort or breathing issues for which physiotherapy is useful.
• Gender affirming genital surgery referrals can be made after 12 months of hormone therapy. The referral form can be found here.

This section looks at how GPs can safely provide repeat prescriptions for patients who have already been commenced on oestrogen based/feminising gender-affirming hormone therapy (E-GAHT).

A testosterone blocker and oestrogen are required, with neither fully effective in isolation.

Oestrogen

The funded formulations of oestrogen are transdermal patches or oral tablets. Patches may be preferable due to a lower thromboembolic risk. Transdermal oestrogen avoids liver metabolism, so is also the preferred choice if there is any liver function impairment.

Testosterone blocker

There is a choice of two as per the table below. Choice of blocker may depend on prescriber or patient preference. If the patient has an orchiectomy, the blocker can be stopped.

Once someone is well established on GAHT, you may wish to see them once a year to:

• Check they are happy with their hormones and the effects.
• Address any questions, concerns or side effects.
• Ensure BP and blood test monitoring is up to date
• Check if any referrals for other gender-affirming care are required.

Blood tests should be checked 3-6 monthly in the first year and annually thereafter.

Monitoring blood tests for a patient on oestrogen-based GAHT:

Cardiovascular risk

In someone with risk factors for thrombosis and increased cardiovascular risk (e.g. smoking, IHD, migraine with aura, older age), it's recommended to use oestrogen patches at the lowest effective dose, and a discussion about the potential risk of cyproterone is warranted.

There is limited data available, but given the increased VTE risk when using cyproterone in other contexts (e.g. GINET), this would seem sensible.

Patients need to be informed of the risk of oestrogen increasing the risk of thrombosis and CVD, but it would be unethical to withhold treatment. The benefits of GAHT (and the risks of withholding it) need to be weighed against any potential increased risk.

Progesterone

Some clients may request progesterone treatment, particularly to support breast development. At present, there is no good quality evidence to support an effect, and it may increase the risk of venous thromboembolism. Therefore, most guidelines, including the NZ guidelines, recommend against its use as part of feminising GAHT.

Other considerations

• Ensure you have recorded the patient's desired name and pronouns on your PMS.
• Feminising GAHT causes infertility, and patients should have been offered fertility preservation before starting GAHT.
• Gender affirming voice therapy is available in some regions
• Gender affirming genital surgery referrals can be made after 12 months of hormone therapy. The referral form can be found here.

This MedCase was written in 2022 by Dr Rona Carroll ( she/her), Senior Lecturer University of Otago and General Practitioner and reviewed by Professor Bruce Arroll, University of Auckland.