A MULTICENTER COMPARATIVE-STUDY ON THE EFFICACY, SAFETY, AND ACCEPTABILITY OF THE CONTRACEPTIVE SUBDERMAL IMPLANTS NORPLANT(R) AND NORPLANT(R)-II

In order to assess efficacy, safety, and acceptability of the contrace ptive subdermal implants Norplant(R) and Norplant(R)-II in Mexican wom en, a comparative phase III clinical trial was undertaken in eight cli nics across the country. The study involved 1052 women who were follow ed-up trimonthly for three years. Cumulative pregnancy rates were 0.29 % and 0.34% for Norplant and Norplant-II implants, respectively. Simil ar overall cumulative discontinuation rates were observed at three yea rs: 50.38% for Norplant capsules, and 50.44% for Norplant-II rods. The main method-related reason for termination was endometrial bleeding i rregularity which led to discontinuation rates of 11.94% and 11.62% fo r Norplant and Norplant-II contraceptive systems, respectively. In 15, 279 woman-months of experience accumulated with Norplant implants and 14,092 with Norplant-II implants, there were few adverse events report ed. No difference was found between the two groups in either difficult y for implants placement and removal or women's discomfort, even thoug h the time required for insertion and removal of Norplant capsules was longer than for Norplant-II rods. It is concluded that during the fir st three years of use, both implants systems are equally effective, sa fe, and acceptable. (C) 1997 Elsevier Science Inc. All rights reserved .