title: A multicentred phase III comparative clinical trial of Mesigyna, Cyclofem and Injectable No. 1 given monthly by intramuscular injection to Chinese women. I. Contraceptive efficacy and sid effects.
abstract: A phase III clinical study was carried out among 5680 fertile Chinese women to evaluate efficacy and side effects of three monthly injectable contraceptives: Mesigyna, Cyclofem and Chinese Injectable No. 1. When used in a once-a-month treatment schedule (part 1 of study), the effectiveness of Chinese Injectable No. 1 was unacceptably low; 36 pregnancies occurred during the first 1743 women-months of use, 16 before the second injection. The study was restarted with a revised injection schedule for Injectable No. 1: two injections separated by 9 +/- 1 days during the first month and subsequent injections given 10-12 days after the onset of bleeding, or if no bleeding occurred, 28 days after previous injection. In part 2 of the study, 988, 990 and 992 subjects were provided Mesigyna, Cyclofem and Injectable No. 1, respectively. Life-table pregnancy rates at one year were 0.41%, 0% and 0.77% (p < 0.05), respectively; the overall discontinuation rates at one year were 13.9%, 19.1% and 20.4% (p < 0.001). Discontinuation rates for bleeding problems were significantly different between the groups: discontinuation rates for amenorrhea were 0.58%, 3.71% and 0.68% (p < 0.001) for Mesigyna, Cyclofem and Injectable No. 1; for other bleeding problems, the rates were 4.88%, 8.38% and 12.64% (p < 0.001). There were no significant differences between the groups regarding discontinuation for other medical or non-medical reasons. Mean weight changes after one year of use were small: 0.73, 0.86 and 0.17 kg for the three groups, respectively. Both Mesigyna and Cyclofem were very effective for contraception, but Mesigyna appeared to be tolerated slightly better with regard to cycle control; the modified dose regimen for Injectable No. 1 also gave a low pregnancy rate but was associated with higher rates of discontinuation.
authors.affiliation: WHO CCR for Human Reproduction, Family Planning Research Institute of Zhejiang, Zhejiang Academy of Medical Sciences, Hangzhou, China.
authors.forename: G W
authors.initials: GW
authors.lastname: Sang
authors.forename: Q X
authors.initials: QX
authors.lastname: Shao
authors.forename: R S
authors.initials: RS
authors.lastname: Ge
authors.forename: J L
authors.initials: JL
authors.lastname: Ge
authors.forename: J K
authors.initials: JK
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Song
authors.forename: K J
authors.initials: KJ
authors.lastname: Fang
authors.forename: M L
authors.initials: ML
authors.lastname: He
authors.forename: S Y
authors.initials: SY
authors.lastname: Luo
authors.forename: S F
authors.initials: SF
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000139:chemically induced; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D002681:China; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000009:adverse effects / Q000592:standards*; D003277:Contraceptives, Oral, Combined / Q000008:administration & dosage / Q000009:adverse effects / Q000592:standards; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004958:Estradiol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000592:standards; D005260:Female; D006801:Humans; D006908:Hydroxyprogesterones / Q000008:administration & dosage / Q000009:adverse effects / Q000592:standards*; D007273:Injections, Intramuscular; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000009:adverse effects / Q000592:standards*; D008597:Menstrual Cycle / Q000187:drug effects / Q000502:physiology; D008599:Menstruation Disturbances / Q000139:chemically induced; D009640:Norethindrone / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000592:standards; D010352:Patient Dropouts
chemical_list: D003271:Contraceptive Agents, Female; D003277:Contraceptives, Oral, Combined; D004338:Drug Combinations; D006908:Hydroxyprogesterones; C094853:Injectable No. 1; C418365:estradiol, norethindrone drug combination; D004958:Estradiol; C034528:CycloProvera; D017258:Medroxyprogesterone Acetate; D009640:Norethindrone