Benefits of different routes of administration.

The benefits of hormone replacement therapy (HRT) are well established for the different systemic administration routes used today. Relief from somatic and vasomotor postmenopausal symptoms can be obtained by all recognized forms of HRT. The prophylactic action of peroral and percutaneous administration of HRT on postmenopausal bone loss is identical if the appropriate protective dosage of the estrogen component is chosen for each galenic form. The second metabolic benefit of HRT, the cardioprotective effect of ERT, is well accepted for the peroral route. New data on the direct effect of estradiol on the arterial wall as well as recent serum lipid results obtained during percutaneous administration of estradiol in postmenopausal women allow the conclusion that the percutaneous route induces cardioprotection similar to that obtained with the classical peroral route. This opinion is supported by animal data. Furthermore, observations in animals suggest that the benefits of ERT are not neutralized by either sequential or fixed addition of progestin to the estrogen. Except in some rare cases with a particular indication for either the peroral or the percutaneous administration of HRT, the choice of route of administration should be made on the basis of maximum acceptability by the patient.