HRT: Route of HRT
- Route of HRT.
If estrogen is only required for vaginal or urinary symptoms, vaginal estrogen is available in the form of a tablet, cream, pessary, gel or vaginal ring. If estrogen is required for more general symptoms such as flushes, sweats, joint aches or poor sleep, then it is taken in a form which circulates throughout the body and is known as systemic HRT. Systemic estrogen can be taken as a daily tablet (oral), or through the skin by a weekly or twice weekly patch, a daily gel or a daily spray (transdermal). Estrogen implants given 6 monthly have been used in the past but are no longer readily available. Estrogen combined with progestogen can be taken by tablet or weekly or twice weekly patch, and progestogen alone can be taken by tablet, vaginal gel or by a progestogen releasing intra-uterine system-eg Mirena. The different routes of estrogen used have different metabolic effects (e.g. on clotting factors and blood fats) so that there may be different benefits and risks from different routes. The main factors determining choice of route are individual preference, response and past medical history. Often, HRT can be started in tablet form, which provides many benefits and minimal risks in a convenient form.
Indications for transdermal route of Estrogen.
- Individual preference.
- Poor symptom control with tablet HRT.
- Side effects such as nausea with tablet.
- Bowel disorder which may affect absorption of tablet therapy.
- History of migraine (when steadier hormone levels which may be achieved with a patch may be beneficial).
- Lactose sensitivity (all tablet preparations of HRT contain lactose).
- History of gallstones.
- Current use of medications such as anti-epileptic medication which may interfere with the break-down of tablet HRT.
- Variable blood pressure.
- High triglyceride levels.
- Risk factors for deep vein thrombosis including Body Mass Index greater than 30, family history or past history of deep vein thrombosis or pulmonary embolus, after full discussion and specialist advice when necessary. Because risk of deep vein thrombosis increases with age, transdermal route should also be considered when HRT is continued over the age of 60.