Long-acting hormonal contraceptives for women.
J Steroid Biochem Mol Biol
; 40(4-6): 697-704, 1991.
Article
in En
| MEDLINE
| ID: mdl-1958567
ABSTRACT
PIP: A survey of recent trials of new injectable hormonal contraceptives, progestogen-only, levonorgestrel esters, and once monthly injectables, follows a brief review of all the experimental long-acting contraceptive modalities, injectables, implants, vaginal rings, and hormone-releasing IUDs. Currently medroxyprogesterone acetate (DMPA) and norethisterone enanthate (NET-EN) are being used by 7 million women. WHO is conducting dose reduction trials and studies of bioavailability in various national populations. Even though a dose of 100 mg DMPA every 3 months has been satisfactory for contraception, 150 mg is still recommended until further pharmacodynamic data are available. Some populations, notably Thais and Mexican women, have higher peaks and more rapid elimination rates of DMPA, while Chinese women show slower elimination and higher blood levels of NET-EN. Extensive studies of new synthetic esters of levonorgestrel have proceeded to Phase II clinical trials with levonorgestrel butanoate. This ester is an effective contraceptive for 3 months at 12.5 mg, or 5-6 months at a dose of 25 or 50 mg. Trials of combined estrogen and progestogen injectables once-monthly have been ongoing for 10 years. The ratio of the 2 components is as important as the amounts. 2328 women from 12 countries participated in trials of DMPA 25 mg-estradiol cypionate 5 mg, and NET-EN 50 mg-estradiol valerate 5 mg. The continuation rate was better than that for 3-monthly progestogen-only injectables, because of less irregular bleeding. A combined injectable called Cyclofem, DMPA 25 mg-estradiol cypionate is being introduced in several countries. The steadily increasing demand for long-acting injectables prompts development of better formulations.
Key words
Clinical Research; Contraception; Contraception Continuation; Contraception Research; Contraceptive Agents, Estrogen--administraction and dosage; Contraceptive Agents, Female--administraction and dosage; Contraceptive Agents, Progestin--administraction and dosage; Contraceptive Agents--administraction and dosage; Contraceptive Implants; Contraceptive Methods; Contraceptive Mode Of Action; Contraceptive Usage; Depo-provera--administraction and dosage; Estradiol Enanthate--administraction and dosage; Family Planning; Human Volunteers; Iud; Iud, Hormone Releasing; Levonorgestrel--administraction and dosage; Literature Review; Medroxyprogesterone Acetate--administraction and dosage; Norethindrone Enanthate--administraction and dosage; Norethindrone--administraction and dosage; Ovulation Suppression; Research Methodology; Vaginal Rings
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Contraceptive Agents, Female
/
Norethindrone
Limits:
Female
/
Humans
Language:
En
Journal:
J Steroid Biochem Mol Biol
Journal subject:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Year:
1991
Document type:
Article
Affiliation country:
Mexico
Country of publication:
United kingdom