AN AUDIT OF ESTRADIOL LEVELS AND IMPLANT FREQUENCY IN WOMEN UNDERGOING SUBCUTANEOUS IMPLANT THERAPY

OBJECTIVES The aim of the study was to review our long-term use of sub cutaneous oestradiol (E(2)) implant therapy for the treatment of clima cteric symptoms in post-menopausal women, On the grounds that the aim is to restore premenopausal serum E(2) levels, our declared clinical p olicy is not to repeat implants even in the presence of symptoms if se rum E(2) levels are >400 pmol/l. Therapy was with 50 mg E(2) implants inserted subcutaneously in the lower abdominal wall. DESIGN All women who had attended the gynaecological/endocrinological clinic who had re ceived subcutaneous E(2) implants for the relief of climacteric sympto ms between December 1981 and 1992 were included. RESULTS Between Decem ber 1981 and December 1992, 275 women received a total of 759 50 mg E( 2) implants. The median length of implant therapy was 34.2 months (ran ge 3.7-109.5 months), and the median number of implants per patient wa s 4 and ranged from 1 to 13. One hundred and twenty-nine women had mor e than four implants and their mean recorded serum E(2) level was 425 +/- 187 (mean +/-SD) pmol/l; the mean level over the first 24 months o f therapy was 408 +/- 157 pmol/l. This was not different from the mean value of the remaining period of therapy (439 +/- 168 pmol/l). Follow ing the second implant there was no significant progressive rise in se rum E(2) with time and implant number and the mean E(2) level per pati ent was no higher in those patients who received implants more frequen tly. The mean time between the first two implants was 9.7 +/- 0.4 mont hs and between subsequent ones was 11.7 +/- 0.5 months. After the firs t two implants there was no progressive change in this interval with t ime. CONCLUSION This study shows that effective, safe and sympathetic management of women with oestrogen deficient symptoms may be achieved by use of two criteria to determine re-treatment; the return of sympto ms, and a serum E(2) level no higher than 400 pmol/l. Once therapy is established, E(2) implants may need to be prescribed only on an annual basis. There appears to be no justification for giving E(2) implants more frequently as this policy achieves satisfactory (physiological) p remenopausal E(2) levels and good symptomatic relief without any evide nce for accumulation of E(2) or 'tachyphylaxis'.