Page 745 - Basic _ Clinical Pharmacology ( PDFDrive )

CHAPTER 40 The Gonadal Hormones & Inhibitors 731

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TABLE 40–3 Some oral and implantable contraceptive agents in use. (Continued)
Estrogen (mg) Progestin (mg)
4-Phasic Combination Tablet
Natazia
Days 1–2 Estradiol valerate 3 None —
Days 3–8 Estradiol valerate 2 Dienogest 2
Days 9–25 Estradiol valerate 2 Dienogest 3
Day 26–27 Estradiol valerate 1 None —
Daily Progestin Tablets
Camila, Errin, Heather, Jencycla, Jolivette, Lyza, Nora-BE, Nor-QD, Ortho None — Norethindrone 0.35
Micronor
Contraceptive Transdermal Patch (Apply 1 Patch per Week)
Ortho Evra Ethinyl estradiol 0.02/24 h Norgestromin 0.150/24 h
Implantable Progestin Preparation
Implanon, Nexplanon None Etonogestrel (one tube of 68 mg)
1 The estrogen-containing compounds are arranged in order of increasing content of estrogen. Other preparations are available. (Ethinyl estradiol and mestranol have similar
potencies.)

Oral contraceptives containing the progestin cyproterone acetate even when untreated. On the other hand, progesterone was given
(also an antiandrogen) in combination with ethinyl estradiol are experimentally to delay premature labor with encouraging results.
investigational in the United States. Progesterone and medroxyprogesterone have been used in the
treatment of women who have difficulty in conceiving and who
Clinical Uses demonstrate a slow rise in basal body temperature. There is no
convincing evidence that this treatment is effective.
A. Therapeutic Applications Preparations of progesterone and medroxyprogesterone have
The major uses of progestational hormones are for hormone been used to treat premenstrual syndrome. Controlled studies
replacement therapy (see above) and hormonal contraception have not confirmed the effectiveness of such therapy except when
(see below). In addition, they are useful in producing long-term doses sufficient to suppress ovulation have been used.
ovarian suppression for other purposes. When used alone in large
doses parenterally (eg, medroxyprogesterone acetate, 150 mg B. Diagnostic Uses
intramuscularly every 90 days), prolonged anovulation and amen- Progesterone can be used as a test of estrogen secretion. The
orrhea result. This therapy has been employed in the treatment administration of progesterone, 150 mg/d, or medroxyprogester-
of dysmenorrhea, endometriosis, and bleeding disorders when one, 10 mg/d, for 5–7 days, is followed by withdrawal bleeding
estrogens are contraindicated, and for contraception. The major in amenorrheic patients only when the endometrium has been
problem with this regimen is the prolonged time required in stimulated by estrogens. A combination of estrogen and progestin
some patients for ovulatory function to return after cessation of can be given to test the responsiveness of the endometrium in
therapy. It should not be used for patients planning a pregnancy patients with amenorrhea.
in the near future. Similar regimens will relieve hot flushes in
some menopausal women and can be used if estrogen therapy is Contraindications, Cautions, & Adverse
contraindicated. Effects
Medroxyprogesterone acetate, 10–20 mg orally twice weekly—
2
or intramuscularly in doses of 100 mg/m every 1–2 weeks—will Studies of progestational compounds alone and with combination
prevent menstruation, but it will not arrest accelerated bone oral contraceptives indicate that the progestin in these agents may
maturation in children with precocious puberty. increase blood pressure in some patients. The more androgenic pro-
Progestins do not appear to have any place in the therapy of gestins also reduce plasma HDL levels in women. (See Hormonal
threatened or habitual abortion. Early reports of the usefulness of Contraception, below.) Two recent studies suggest that combined
these agents resulted from the unwarranted assumption that after progestin plus estrogen replacement therapy in postmenopausal
several abortions the likelihood of repeated abortions was over women may increase breast cancer risk significantly compared with
90%. When progestational agents were administered to patients the risk in women taking estrogen alone. These findings require
with previous abortions, a salvage rate of 80% was achieved. It is careful examination and if confirmed will lead to important changes
now recognized that similar patients abort only 20% of the time in postmenopausal hormone replacement practice.