The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

Letter to the Editor

Editor, – The article 'Managing menopausal symptoms' (Aust Prescr 2010;33:171-5) states that transdermal progesterone cream is minimally absorbed through the skin and there is no good evidence for its usefulness in relieving flushes, or in improving mood, libido or lipid profile.

Transdermal progesterone is poorly absorbed, which may explain the poor results obtained. However, if used transvaginally or rectally, absorption is much better.1

Progesterone does not relieve flushes. It is oestrogen which relieves flushes. However, it is an inhibitor of monoamine oxidase,2,3so it may well improve mood if absorbed in adequate quantities. It also remodels bone,4thus it is useful in counteracting osteoporosis. It has none of the adverse effects of synthetic progestogens, and I found it useful in patients with endometriosis who could not tolerate the synthetic progestins because of weight gain and irritability. Progesterone reversed these adverse effects.

The actions of the synthetic progestogens, apart from the effect on the uterine lining, are different from those of progesterone. Synthetic gestagens have been shown, in fact, to lower the body's production of progesterone.5

Iain Esslemont
General practitioner
Margaret River, WA

Author's comments

Dr Terri Foran, author of the article, comments:

I would like to thank Dr Esslemont for his comments regarding the use of topical natural progesterone for the management of menopausal symptoms. I appreciate that many clinicians and their patients attest to its effectiveness in relieving a range of menopausal and premenstrual symptoms. I stand by my comments however that no large well-designed clinical trials have demonstrated these benefits to date. The small trials that do exist have used different doses, regimens and delivery systems and the results have been extremely variable. I must also admit to some personal concerns as to the quality assurance that governs the manufacturing processes of some of the constituents used in these products.

I am prepared to be convinced by good quality medical evidence that topical natural progesterone cream has a useful role to play in the treatment of menopausal symptoms. I would certainly encourage the manufacturers of these products to undertake such trials. Until that time however I feel it is difficult to recommend natural progesterone, whether transdermal, vaginal or rectal, as an effective therapy in menopausal women.

References

  1. Dalton M, Ambrose CI, Balmer B, Bromham D. Individual variation in absorption of natural progesterone administered by different routes. Br J Fam Plann 1994;19(Suppl):2-3.
  2. Lin YC, Kono H, Zuspan FP, Lee A, Yajima A. Progesterone as an inhibitor of monoamine oxidase. Br J Fam Plann 1994;19(Suppl):6-8.
  3. Kono H, Lin YC, Yamaguchi M, Zuspan FP, Furuhashi N, Takayama K, et al. Effects of progesterone and gossypol on monoamine activity in human term placentalexplants. J Exp Med 1991;163:39-45.
  4. Prior JC, Vigna YM, Kennedy SM. Progesterone's role in bone remodeling. Br J Fam Plann 1994;19(Suppl):13-17.
  5. Johansson EDB. Depression of the progesterone levels in plasma in women treated with synthetic gestagens after ovulation. Acta Endocrinol 1971;68:779-92.