Who can have it?
Several of the contraindications to combined oral contraception are not contraindications to HRT; in particular, being a smoker over 35 is not considered a contraindication at all, even to oral HRT. I suppose that one was worth it to the drug companies to get licenced, considering.
Various other contradictions to COC are only contraindications to oral use; transdermal HRT can be used in women with these conditions (BNF).
- Past MI or stroke*
- BMI >35
- Complicated diabetes
- Migraine with aura
- Venous thromboembolism
*Note that active or recent MI or stroke is considered a contraindication to any form of oestrogen-containing HRT.
Interestingly, oestrogen-only HRT decreases the risk of MI as well as of BC. Combined HRT started under the age of 60 does not increase CV risk, or the risk of dying from a cardiovascular condition whenever it’s started. There is also little evidence that HRT increases the risk of hypertension, and it is now advised that HRT can be safely continued in women with hypertension.
On the flip side, there are contraindications to HRT that are not considered contraindications to COC:
- Ovarian cancer
- Uterine cancer
- Undiagnosed vaginal bleeding
It’s worth noting that family history of breast cancer is not considered a contraindication to either HRT or the COC (although specialist advice is required to prescribe the COC to a woman with a BRCA mutation). However, NICE advice is that, in prescribing for women with a family history of breast cancer, HRT should be restricted to as short a duration and as low a dose as possible and that oestrogen-only HRT should be preferred where possible.
Vaginal oestrogens for urogenital atrophy may be useable even in women for whom systemic HRT is contraindicated (latest NICE guidance). Where possible, collaborate with their secondary care specialist and with the local menopause care specialist.
What to choose for starting
Note indications for transdermal HRT as above.
Aim to start out with a decent dose (to get symptoms under control quickly) and to consider reduction later.
The reason for starting with sequential HRT in women who’ve had less than a year of amenorrhoea is because there’s a greater risk of breakthrough bleeding if they start on continuous combined, and the idea is to avoid the unnecessary investigations this can trigger. This means that women who started on sequential HRT can move to continuous combined once they’re definitely through the menopause, but the tricky bit is in figuring out what counts as ‘definitely through the menopause’. By 54, 80% of women will be postmenopausal, so this is often taken as a point at which changeover can be made, but of course that means there’s still a risk of breakthrough bleeding in 20% of women.
(This, of course, all raises the question of whether breakthrough bleeding in women with HRT needs to be automatically investigated at all, given that the increased likelihood in this group means it has much lower positive predictive value as a symptom. The British Menopause Society handbook has what sounds like a sensible answer to this; it advises that irregular bleeding within the first six months of starting HRT does not need investigating unless it becomes heavier, persists after the six-month mark, or starts after a significant period of amenorrhoea. The Pulse Learning module advises using local protocols in this manner.)
NICE recommends HRT review three months after starting, then annually, to assess symptom control and any changes in risk. In view of the lack of evidence that hypertension should affect HRT use, it’s very debatable whether we really need to measure BP at each appointment.
When to stop
We don’t have a cut-off date for stopping HRT; problems appear to be due more to late start than to duration (benefits are higher and risks lower when started closer to menopause rather than later). Risks and benefits should be weighed up individually for each woman.
Alternatives for menopausal symptoms
I already wrote about these here, but hadn’t realised that fluoxetine and paroxetine are actually contraindicated in women taking Tamoxifen. (I don’t know why this is.)
Clonidine is apparently an option for women suffering exaggerated menopausal symptoms on Tamoxifen. It’s about the only thing it is useful for, given the side-effect profile (dry mouth, sedation, nocturnal restlessness, dizziness, and nausea) and the conflicting evidence on effectiveness. On the plus side, we have thirty years of experience with it and it’s the only non-HRT product licenced for menopausal symptoms.
I obviously knew about the potential carcinogenic risks with herbal remedies, plus the lack of evidence of effectiveness for most of them, but one aspect I hadn’t thought of was that the lack of quality control on herbal remedies means there’s a small risk of contaminants which could, in a worst-case scenario, cause liver or renal damage.
(Source: Pulse on-line learning module)