An audit of oestrogen implant hormone replacement therapy

The aim of this review was to determine the factors that impact upon oestra diol levels in patients receiving oestradiol implants and to assess the rel ationship between symptom scores and oestradiol levels. In addition we soug ht to determine the incidence of tachyphylaxis (menopausal symptoms in spit e of high oestradiol levels) among our patients, and to assess the degree o f menstrual cycle control in the nonhysterectomized women receiving implant treatment. We undertook an audit of the medical records of 118 women who r eceived 673 oestradiol implants (50 or 100 mg) over an 8-year period in the menopause clinics at Royal North Shore Hospital. Data on patient age, clin ical diagnosis, symptom score, previous or subsequent hysterectomy, oestrad iol implant dosage (50 mg or 100 mg), number of doses, oestradiol levels an d concurrent testosterone implant insertion were recorded. We found that im plant dosage (p<0.001) and implant number (p<0.001) were the factors that s ignificantly impact upon oestradiol levels. Concomitant testosterone implan t usage (p=0.74), patient age (p=0.14) and hysterectomy (p=0.57) did not ha ve a statistically significant effect upon oestradiol levels. The incidence of tachyphylaxis was 1.7% (2 patients). There was no relationship between oestradiol levels and symptom scores (p=0.69). Oestradiol implant treatment , when administered on the basis of return of symptoms, without a strict ta rget oestradiol level, results in a steady increase in baseline oestradiol levels. The dosage used and the number of implants received are important f actors influencing oestradiol levels. The incidence of tachyphylaxis is low when patients are counselled regarding the lack of agreement between sympt om scores and oestradiol levels.