The use of micronised progesterone for menopausal hormone therapy, a clinical practice audit

A clinical practice audit was undertaken to share an Australian experience of the use of micronised progesterone (mP) 100 mg daily as part of menopausal hormone therapy (MHT). Ninety-nine women attending a single practitioner were offered the option of mP as a component of MHT, under the Australian Authorised Prescriber Scheme, over 2.5 years. Each of their files was independently audited. The mean age at commencement was 55.0 (SD 6.6) years. Of the 93 postmenopausal women, 7 were lost to follow-up, 18 discontinued and treatment was ongoing for 68. The mean duration of treatment for those ongoing was 1.7 (SD 0.5) years, and for those who discontinued, 0.6 (SD 0.6) years. The most common side effect was unscheduled bleeding, which was also the most common reason for discontinuation (5/18 women). None of the 15 women who had a transvaginal ultrasound examination had an endometrial thickness >5 mm. Of the 41 women who had at least one blood progesterone measurement performed, the median value was 11.3 (range 0.7-138) nmol/L. This audit indicates that mP is well tolerated when prescribed as MHT. Although there was no evidence of endometrial hyperplasia, further research is needed to establish the safety of mP for continuous combined MHT use.