Oestrogen

Oestrogen related side effects include:

• Fluid retention.
• Bloating.
• Breast tenderness or enlargement.
• Nausea.
• Headaches.
• Leg cramps.
• Dyspepsia.
• Hyperpigmentation of skin.
• Vaginal bleeding.
• Mood disturbance.
• Tachyphylaxis.
• Exogenous oestrogens may induce or exacerbate symptoms of hereditary or acquired angioedema.
• High doses of oestrogen increase the risk of abnormal bleeding requiring investigation, endometrial hyperplasia and endometrial cancer.

STRATEGIES TO REDUCE SIDE EFFECTS INCLUDE:

1. TIME

• Oestrogen related side effects during the first 3 months of treatment are common and often improve with time, usually after 2–3 months.

2. REDUCING THE OESTROGEN DOSE

• When oestrogen related side effects occur, they appear to be dose related and lowering the dose often alleviates things. This is particularly the case for breast tenderness.
• If using a matrix patch, the dose can be reduced predictably by cutting the patch. Sometimes just cutting a small corner off is enough to help.
• The quantity of gel or spray can be reduced easily by the user.
• If using an oral regime, sometimes a lower tablet strength can be prescribed or if already using a low strength, the frequency adjusted to alternate days.
• Using a lower dose for longer and gradually increasing the strength improves tolerability.

3. ADJUSTING ADMINISTRATION TIMINGS

• Splitting the dose. Most apply the gel or spray once daily, however when side effects occur, sometimes giving half the dose twice daily helps.
• When using the patch, if menopause symptoms are well controlled after the patch is first applied, but then symptoms return before the patch is due to be replaced, the patch change day can be brought forward, for example to every 3 days.
• Sometimes just changing the dose timings can be helpful, for example, switching the timing of tablet ingestion.

4. SWITCHING PREPARATION

• There are considerable intraindividual differences in the metabolism and absorption of estradiol between preparations. For some, just switching to another preparation alone can improve side effects.
• In general, side effects are less with transdermal preparations because they usually produce more stable hormone levels.