El Gestágeno Ideal para la Terapia Hormonal Bloquea los efectos proliferativos de los estrógenos sobre el endometrio Buen perfil de sangrado No impide los efectos benéficos de los estrógenos No posee otra actividad hormonal Puede proporcionar otros beneficios adicionales: Calidad de vida Ánimo Peso Hueso NOTES 1. This is the profile of the 'ideal' progestin. 2. In women receiving estrogen replacement therapy, blocking estrogenic proliferation of the endometrium provides protection against endometrial carcinoma. 3. Endogenous estrogen is widely regarded as having beneficial effects on vasomotor symptoms and bone. Ongoing research is investigating its effect on other systems, including the central nervous system and the cardiovascular system. Hence, to replace it with a suitable regimen of combination HRT requires a progestin which does not block these desirable actions of administered estrogen. 4. Skin problems such as acne and seborrhea, together with hirsutism and masculinization, are undesirable and the ideal progestin, therefore, has no androgenic activity and may even have antiandrogenic activity. 5. Mineralocorticoid activity involves retention of water and sodium and is associated with weight gain. Hence some antimineralocorticoid activity of a progestin may be desirable in counteracting the tendency of some women to gain weight under HRT.

Clasificación de Progestágenos Esteroides Naturales Presentes en laNaturaleza Sintéticos (progestinas) Sintetizadas en Laboratorios Relacionadas Estructuralmente a la Progesterona Relacionadas Estructuralmente a la Testosterona Progesterona Derivados Pregnano MPA Acetato de Megestrol Acetato de Ciproterona Acetato de Clormadinona Medrogestona Dydrogesterona 19-Norpregnano Derivadas Acetato de Nomegestrol Demegestona Trimegestona Promegestona Nesterona Etiniladas Noretindrona Noretinodrel Lynestrenol Acetato de Noretindrona Tibolona Acetato de Etinodiol Levonorgestrel Desogestrel Norgestimato Gestodeno No etiniladas Dienogest Drospirenona Progestins can be divided into two types: natural and synthetic. However, the only natural progestin is progesterone, which can be found in humans and certain animals, but not in plants. Synthetic progestins are defined as progestins that are synthesized chemically. Synthesized progestins can be categorized into two groups: those that are structurally related to progesterone, and those that are structurally related to testosterone. This classification scheme does not imply the source of the steroid precursor. Progestins that are structurally related to progesterone can be subdivided into those with (pregnane derivatives) and without (19-norpregnane derivatives) a methyl group at carbon 10. Pregnane derivatives include MPA and megestrol acetate, while 19-norpregnane derivatives include trimegestone and demegestone. Both pregnane derivatives and 19-norpregnane derivatives can also be classified as to whether they are acetylated or nonacetylated. All pregnane-derived progestins are acetylated except dydrogesterone, and all 19-norpregnane derivatives are nonacetylated besides nomegestrol acetate. Progestins structurally related to testosterone are either ethinylated (those that contain an ethinyl group at carbon 17) or nonethinylated. Ethinylated progestins include norethindrone acetate and levonorgestrel. Dienogest and drospirenone are the only nonethinylated progestins. Ethinylated progestins can be further divided into those that have an estrane structure, such as norethindrone and tibolone, and those with a 13-ethylgonane structure, such as norgestimate. Stanczyk FZ. Rev Endocr Metab Disord. 2002;3:211-24. Stanczyck FZ. Pharmacokinetics and potency of progestins used for hormone replacement therapy and contraception. Rev Endocr Metbo Disord. 2002;3:211-224.

“Arbol de los Gestágenos” Agonistas puros Efectos antiandrogé- nicos parciales CMA = acetato clormadinona CPA = acetato ciproterona DNG = dienogest DRSP = drospirenona DSG = desogestrel GST = gestodeno MGA = acetato megestrol LNG = levonorgestrel MPA = acetato medroxiprogesterona NETA = acetato noretindrona TMG = trimegestona Efectos antiestro- génicos parciales Progesterona TMG CPA CMA DNG Efectos androgé- nicos parciales LNG Efectos estrogé- nicos parciales LNG DSG GST NETA Efectos antimineralo- corticoides Efectos glucocorticoi- deos parciales MPA MGA DRSP

Manejo práctico de TRH El papel de las progestinas es proteger el endometrio* Dosis altas de progestina pueden asociarse con perfiles metabólicos menos favorables* Las razones más comunes para suspender el tratamiento son el sangrado, temor al cancer y temor a aumentar de peso * Oettel ,M et al Climacteric 2002; 5 (Suppl 1): 25-26