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Biomedical subjects

I Sivin

Publications and source records attributed to I Sivin.

At least 55 records · Page 3Linked to original sources
PubMed1990

A randomized trial of the Gyne T 380 and Gyne T 380 Slimline Intrauterine Copper devices.

To facilitate manufacture and insertion of the Gyne T 380 IUD, design changes were instituted. Copper collars were seated flush at the ends of the horizontal crossbar of the device. A randomized study of the Gyne T 380 Slimline, the new design, was undertaken in comparison with the standard Gyne T 380. A total of 996 women were enrolled, with 698 Slimline insertions and 298 of the standard Gyne T. No statistically significant difference in ease of insertion or in performance was detected between the models. At one year, the pregnancy rate of each model was below 0.5 per 100 and the continuation rate was 79-80 per 100. Pelvic inflammatory disease or endometritis was found in one percent of subjects in the first year. This is the seventh multicenter randomized study of a collared T IUD with 380 mm2 of copper surface. In all seven, the one-year gross pregnancy rate has been 1.2 per 100 or lower.

Adult↗
PubMed1990

Clinical assessment of treatments for prolonged bleeding in users of Norplant implants.

The effectiveness of three drugs in controlling prolonged bleeding in the first year of NORPLANT implants use was tested. The drugs were levonorgestrel (L-Ng, 0.03 mg twice a day for 20 days), ethinylestradiol (EE, 0.05 mg per day for 20 days) and ibuprofen (Ib, 800 mg three times a day for 5 days) and were given orally. A control group received a placebo (PL, one pill of lactose for 20 days). Treatment should start each time a woman experienced eight consecutive days of bleeding or spotting. The 183 volunteers were not aware of the drug administered. A daily record of bleeding and spotting and of treatment intake was maintained. One-hundred-forty women completed the study period; 60 never used the prescribed treatment. Women treated with the three test drugs had significantly fewer bleeding and spotting days during the treated month and also throughout the study year than women using the placebo. The mean number of bleeding plus spotting days per actually treated subject in the first year was 77, 94, 101 and 129 days for the EE, Ib, L-Ng and PL groups, respectively. The administration of EE might help in the management of prolonged bleeding during the first year of NORPLANT implants use.

Administration, Oral↗
PubMed1989

The Prentif cervical cap and Pap smear results: a critical appraisal.

An analysis from a randomized study has suggested that a larger percentage of Class III Pap smears appears among Prentif cervical cap users three months after initiation of use of the method than among diaphragm users. This suggestion has been the basis of a U.S. Food and Drug Administration (FDA) requirement that women seeking to use the cap have Pap smears taken before initiating use and again after three months of use. The data from the pivotal randomized study are reanalyzed here. No significant differences exist in the distributions of smears between cap and diaphragm users at three months or throughout the first year. The majority of cap users with "Class III" smears at three months did not have even mild dysplasia when subsequently evaluated by biopsy or colposcopy. This was also the case for diaphragm users classified as having grade III smears at three months. Other studies of the Prentif cap have not found conversions to Class III smears at one year. The requirement of a 3-month Pap smear is not only economically burdensome to potential users of the cap but appears to be without firm foundation in the original data or in our current views of cervical carcinogenesis.

Adult↗
PubMed1988

Contraception with NORPLANT implants and NORPLANT-2 implants (two covered rods). Results from a comparative clinical study in Sweden.

Two-hundred-and-forty healthy women, ages 18 to 40 years, were randomized in a ratio of 2:5 to use NORPLANT implants or NORPLANT-2 implants. Through three years of use, no pregnancies were recorded among women using NORPLANT implants and two pregnancies were noted among women using NORPLANT-2 implants resulting in a cumulative net pregnancy rate of 1.3 +/- 0.9 per 100 acceptors (mean +/- SE) by the end of year three. This difference was not statistically significant. During the fourth year, no pregnancies were observed in the NORPLANT group, but 4 pregnancies occurred in the NORPLANT-2 group. The most common reason for terminating the study was bleeding disturbances. During the first year there were significantly more terminations due to bleeding problems in the NORPLANT group than in the NORPLANT-2 group. However, during the second year of use the proportion of women discontinuing for bleeding problems dropped considerably among NORPLANT users and during the third year very few women in either group discontinued because of bleeding problems. The continuation rates after one year were for NORPLANT users 59.4% and for NORPLANT-2 users 77.2%. Corresponding figures after three years of use were 46.1% and 51.7%, respectively. The second most common reason for discontinuation was depression and other mood changes. In both groups we noted a slight increase in weight during the study and a slight decrease in blood pressure and hemoglobin levels with time. In conclusion, both NORPLANT and NORPLANT-2 implants are very effective methods for contraception. The efficacy of NORPLANT-2 implants, however, was not acceptable during the fourth year of use in this study. The latter system could, however, become a suitable three-year contraceptive method, possibly with less bleeding disturbances than NORPLANT in the first year.

Adolescent↗
PubMed1987

Two years of intrauterine contraception with levonorgestrel and with copper: a randomized comparison of the TCu 380Ag and levonorgestrel 20 mcg/day devices.

IUDs releasing 20 mcg/day of levonorgestrel (LNg20) were in randomized trial together with the Copper T, model TCu 380Ag, in seven centers involving 2244 women. Two-year (25 months) gross cumulative pregnancy rates were 0.2 +/- 0.2 and 0.9 +/- 0.3 for the levonorgestrel and copper releasing devices, respectively (P greater than 0.05). There were no ectopic pregnancies in more than 1600 woman-years of use of each device. Removal rates for bleeding and/or pain or for medical reasons other than menstrual problems did not differ significantly between devices. Oligomenorrhea or amenorrhea prompted 10.7 per hundred (gross rate, 8.4 net rate) women using the LNg 20 IUD to request removal in the two-year period, significantly above the 0.2 per hundred rate among women with the Copper IUD (P less than 0.001). At the end of two years an estimated 59.4 per 100 women were continuing use of the LNg 20 IUD, and 67.5 per 100 (P less than 0.001) with the TCu 380Ag. This difference is almost wholly ascribable to a marked reduction in bleeding episodes and days among women using the LNg 20 device with concomitant removal of device. Hemoglobin rose an average of 0.5 g/dl (P less than 0.001) for this group whereas women using the TCu 380Ag experienced a decline of 0.2 g/dl compared with baseline values (P less than 0.001).

Adolescent↗
PubMed1987

Effectiveness of IUDs: a review.

Large, multicenter, randomized trials of IUDs conducted between 1970 and 1986 encompass more than 50,000 woman-years of experience in the two-year interval following device insertion. Taken singly and collectively, these trials demonstrate that IUD failure rates are strongly affected by the age of participants, notably by the proportion of women under age 25 admitted to the studies. Individual trials and overall comparisons indicate further that: 1. Non-medicated devices such as the Mahua steel ring and Lippes loop D have pregnancy rates above 2 per 100 woman-years. 2. The first approved copper IUDs, the Copper 7 and the TCu 200, do not markedly differ in pregnancy rates from standard plastic devices with rates significantly above 2 per 100 woman-years. 3. Five more recent, widely used copper IUDs have had failure rates significantly below 2 per 100 woman-years in multicenter trials. The point estimate of the failure rate was less than 1 pregnancy per 100 woman-years for three of these IUDs. One copper-bearing device had a failure rate significantly below 1 per 100 woman-years. 4. Devices releasing either 25 mcg/day of progesterone or 2 mcg/day of levonorgestrel have had significantly higher failure rates than the more effective copper-releasing IUDs; however, devices releasing 20 mcg/day of levonorgestrel appear at least as effective as the most effective copper IUDs. Long-term IUD failure rates derived from straight assignment as well as randomized trials indicate 4-year gross cumulative failure rates do not exceed 10 per 100 for any of the standard copper devices or the Lippes loop D. Point estimates of the four-year gross cumulative pregnancy rates have been below 5 per 100 users in studies of the TCu 220C, the Nova T, the TCu 380A, and the MLCu 375.

Adolescent↗
PubMed1986

Recovery of fertility after use of the levonorgestrel 20 mcg/d or Copper T 380 Ag intrauterine device.

Following use of either the Levonorgestrel 20 mcg/day or the TCu 380 Ag IUD in a randomized comparative study, 110 women stopped contracepting to have planned pregnancies. Pregnancy rates and recovery of fertility have been assessed. Age at acceptance, duration of use, parity and intervals between last pregnancy and IUD insertion or removal were similar for both groups. Life table pregnancy rates at one year were higher than 90 per cent for both device groups; but because some women quickly changed their minds or had been at risk of pregnancy only a short time before the analysis date, only 60.9 percent had actually become pregnant. Median time to planned pregnancy was 3 months for the TCu 380 Ag group and 4 months for the Levonorgestrel 20 group. Neither duration of use nor age at insertion or age at termination affected the pregnancy rates significantly.

Adult↗
PubMed1986

Two-year prospective study in Colombia of Norplant implants.

A clinical trial of levonorgestrel-releasing Norplant implants used for contraception was undertaken in two cities in Colombia. Through two years in which 389 women had accumulated 594 years of use, there were no pregnancies. In a comparison group of copper intrauterine device acceptors, the one-year pregnancy rate was 1.1 per 100. Menstrual disturbances associated with progestin-only administration were the principal side-effects, and the major reason for cessation of use. Continuation among users of the implants was at the same or at a higher rate than observed among users of the intrauterine device. Advantages and disadvantages of alternate sites for implant placement are discussed.

Adolescent↗
PubMed1984

Intrauterine contraception with copper and with levonorgestrel: a randomized study of the TCu 380Ag and levonorgestrel 20 mcg/day devices.

First year results of a randomized study of 1509 users of the Copper T380Ag with a silver core or of an IUD releasing 20 mcg day of levonorgestrel are reported. The cumulative gross pregnancy rate for each device was 0.3 per 100 at one year, with more than 490 women having one year of use with each device. The levonorgestrel-releasing device was associated with significantly fewer bleeding days and significantly increased hemoglobin levels when compared with pre-admission values or the one year values observed among users of the TCu380Ag. Terminations attributable to amenorrhea were significantly more frequent among users of the levonorgestrel-releasing device. The TCu 380Ag was associated with increased frequency and severity of dysmenorrhea compared with pre-admission levels or with the steroid-releasing device. Hemoglobin levels were somewhat reduced among users of the TCu 380Ag device. Terminations attributable to pain were, however, not significantly different by device. Continuation rates at the end of the first year were not significantly different by device.

Adolescent↗
PubMed1984

Use effectiveness of the Prentif cervical cap in private practice: a prospective study.

Of two-hundred-sixty women seeking cervical cap contraception, exactly half subsequently used the Prentif cavity rim cap as their sole method of contraception. The one year continuation rate for these exclusive cap users was 56.7 per hundred. No major side effects related to the use of the Prentif cap were observed in the course of this study, involving 918 women-months in year 1. Pregnancy and dislodgement of the cap during use were the principal reasons for discontinuation of exclusive use, with gross rates of 19.1 and 12.9 per 100 at one year, respectively.

Adult↗
PubMed1984

Long-term experience with Norplant implants in international clinical trials.

Norplant subdermal implants containing levonorgestrel were used for contraception and compared with the Copper T, Model T Cu 200, during 42 months of use in an open study in Chile, the Dominican Republic, and Finland. Among 324 women enrolled for the implant regimen, there were no pregnancies in the 1st 2.5 years, and 2 by the end of 42 months. 1st segment net and gross cumulative pregnancy rates were 0.7 and 1.2/100 respectively, at 3.5 years. Cumulative pregnancy rates for the T Cu 200 group were 2.9, net and 3.5/100, gross at 42 months. More than 1/2 of the implant acceptors, 51.6/100 were continuing use at 3.5 years, somewhat above the continuation rate of the T Cu acceptors, 43.5/100, but not significantly so.

Americas↗
PubMed1983

Release rates of levonorgestrel from Silastic capsules, homogeneous rods and covered rods in humans.

Three forms of subdermal implants containing levonorgestrel are described. These are: capsules, in which the powdered drug is sealed inside of lengths of Medical Grade Silastic tubing; homogeneous rods, in which the drug is uniformly dispersed in Silastic 382 Medical Grade Elastomer; and covered rods, in which a core rod of drug and filler-free polydimethylsiloxane polymer (50:50, Wt:Wt) are sealed inside thin-walled Silastic tubing. Long-term in vivo release rates from human subjects are presented; 6.5 years for capsules, 3.6 years for homogeneous rods and 4 years for covered rods. Sets of six capsules release a decreasing amount of drug through the first few hundred days in situ and after 500 days a fairly constant rate of about 35 micrograms per day is released (2 micrograms/cm). Homogeneous rods deliver a continuously declining amount of drug during the entire time studied. In the first 100 days the release averages 136 micrograms per day from a set of three 3-cm rods (15 micrograms/cm), gradually declining to 30 micrograms per day (3.3 micrograms/cm) from day 800 to day 1300. The covered rods deliver at a constant rate of 17.5 micrograms per day for a 3-cm rod (5.83 micrograms/cm) through 4 years.

Capsules↗
PubMed1983

Three-year experience with NORPLANT subdermal contraception.

NORPLANTTM (Laboratorios Gutfol, S.A., Mexico City, Mexico) subdermal implants containing levonorgestrel were accepted by 816 women in a two-phase study initiated in 1975 and augmented in 1978. Through 3 years of first-segment use, acceptors experienced five pregnancies, a cumulative net rate of 0.7 per 100, and a gross pregnancy rate of 1.1 per 100. First-segment continuation at 3 years was at the rate of 44.6 per 100, an annual average of 76 per 100. NORPLANT users experienced irregular menstruation, with high interindividual variation, but with normal average numbers of bleeding days and of bleeding episodes. Hemoglobin levels increased moderately during implant use. The incidence of systolic blood pressure readings above 145 mm Hg or diastolic readings above 95 mm Hg was similar to that observed among users of the TCu 200 intrauterine device enrolled under the same selection criteria in the same clinics between the two phases of the NORPLANT study. Comparative data on pregnancy and other rates are also given for these intrauterine device acceptors.

Adolescent↗