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Biomedical subjects

I Sivin

Publications and source records attributed to I Sivin.

At least 73 records · Page 4Linked to original sources
PubMed1982

A five-year clinical trial of levonorgestrel silastic implants (Norplant TM).

Silastic implants containing the progestin, levonorgestrel, were tested as a long-term contraceptive system in 101 women. During five full years of use, no pregnancies occurred. The 5-year continuation rate was 54%. Menstrual irregularities were the most frequent reason for termination of use but only during the first year. More than half of the terminations for this reason were in the first year. Some of the subjects elected to continue use of the implants beyond 5 years, allowing release rate data to be obtained through 6 years. From the second through the sixth year of use, the implants delivered a constant 30 micrograms per day of levonorgestrel to the subjects, and even after six years 57% of the original steroid content remained in the capsules. Return of fertility following removal was essentially immediate and not related to time of use. Medical reasons for removal were infrequent and no pattern was discernible.

Adult↗
PubMed1981

A multicenter study of levonorgestrel-estradiol contraceptive vaginal rings. II-Subjective and objective measures of effects. An international comparative trial.

Comparative clinical trials of 2 sizes of contraceptive vaginal rings and of an oral contraceptive were undertaken at 8 investigational sites (9 clinics). More than 500 women enrolled on each of the 3 study regimens. Side effects of the rings and of Nordette, the oral contraceptive, were evaluated by noting spontaneous complaints, by recording medications taken and by physical examination. Inquiries about changes in the frequency of specific conditions were made at the end of the subjects participation in the first year of the study. The incidence of spontaneous complaints was similar among users of the 2 different-sized rings and of the pill.

Adolescent↗
PubMed1981

A multicenter study of levonorgestrel-estradiol contraceptive vaginal rings. III-Menstrual patterns. An international comparative trial.

Menstrual events among users of contraceptive vaginal rings (CVRs), releasing levonorgestrel and estradiol, were studied in comparison with a combined oral contraceptive, Nordette, in multicentered trials. CVRs were made with outside diameters of 50 and 58 mm and released about 250 micrograms and 290 microgram of levonorgestrel and 150 microgram and 180 microgram of estradiol per day, respectively. The CVRs were used continuously for 3 weeks and then removed for 1 week. Both the CVRs and Nordette were perceived to reduce menstrual flow and days of menstrual bleeding. Twenty to 25% of CVR users perceived increased intermenstrual bleeding or spotting. Diaries indicate, however, that on average, CVR users experienced about 1 day per month of bleeding or spotting with the ring in place. CVRs and Nordette produced approximately the same total number of bleeding and spotting days during 6 cycles of use, 27-29, but the small (50-mm OD) ring was associated with somewhat more spotting. This ring was also associated with somewhat more prolonged bleeding and spotting runs and with more prolonged nonbleeding intervals than reported by users of the larger (58-mm OD) ring or of Nordette. Differences among regimens, however, tended to be small even when statistically significant. Evidence from menstrual diaries indicates that these CVRs, and in particular 58-mm ring, provide control over the menstrual cycle comparable to the Nordette.

Adolescent↗
PubMed1981

Lipoprotein patterns in women in Santo Domingo using a levonorgestrel/estradiol contraceptive ring.

Ten healthy, normally menstruating women attending a family planning clinic in Santo Domingo Participated in a study to determine the effects on plasma lipid levels of levonorgestrel and estradiol released from a contraceptive ring. A schedule of 21 days of use followed by 7 days of non-use was followed for 6 cycles. During the first two cycles of use, concentrations of cholesterol, HDL cholesterol, triglycerides and LDL cholesterol declined significantly from control levels, up to 25% for cholesterol, 28% for HDL cholesterol, 45% for friglycerides and 24% for LDL cholesterol. There were no subsequent changes with continued use. These declines are similar in direction but of lesser magnitude than those reported from clinics in other countries where pretreatment plasma levels of the same lipids are considerably higher. There was no significant change in the total cholesterol to HDL cholesterol ratio during treatment.

Adolescent↗
PubMed1981

Long-term contraception with a single implant of the progestin ST-1435.

Silastic capsules containing the synthetic progestin ST-1435 was inserted in 282 women of reproductive age who desired long-term contraception. Each woman received a single implant for 6 months' use. After evaluating the experience of the first 45 subjects, replacement capsules were offered to women desirous of continuing the method after the initial 6 months of use. In the first 6-month segment one pregnancy and 1720 woman-months of use were recorded. The total experience, through as many as six segments of use was 3373 woman-months of use and one pregnancy. The Pearl Index is 0.36 per 100 woman-years. The single pregnancy, recorded in the 1st month of the first segment, may represent a conception prior to implant placement. Amenorrhea was the most common side effect reported, with 83% of the women having at least one nonbleeding interval longer than 60 days during the first segment of use.

Amenorrhea↗
PubMed1981

Four years of experience with the TCu 380A intrauterine contraceptive device.

A study of the United States acceptors of the Copper T, model TCu 380A, initiated in 1972, was carried to the completion of 4 years of observation. The 1051 receptors, whose median age was 22.3 years, accumulated a total of 1927 years of use. At the end of 4 years, the cumulative net pregnancy rate was 1.9 per 100 women, and the gross rate was 2.8 per 100. The annual continuation rate over the 4-year interval averaged 77 per 100. The TCu 380A intrauterine device (IUD) has provided extremely effective and undiminishing protection against pregnancy through 4 years of use in a group of young women. This degree of protection has not as yet been equaled when randomized comparative trials have been carried out with other copper-bearing IUDs.

Adult↗
PubMed1979

A randomized double blind study of two oral contraceptives.

To study the question of whether one brand of oral contraceptives may be as acceptable as another for use of publicly-assisted family planning programs, a double blind study of two well-known brands, Ovral and Norinyl, was undertaken in Costa Rica and Trinidad. The pills were randomly assigned to 1,200 women. Common side effects - nausea, dizziness, vomiting, headaches - were associated with both Norinyl and Ovral. Differences in event rates for these conditions were much more marked by country than by the pill used. Ovral was associated with increases in skin problems, notably chloasma, in Cost Rica. A higher percentage of women using Norinyl reported intermenstrual bleeding and spotting in both countries. In Costa Rica continuation rates for Norinyl were adversely affected by this. With these exceptions there appear to be no important differences between the brands that would affect their use in family planning programs.

Adolescent↗
PubMed1979

Copper T IUD use and ectopic pregnancy rates in the United States.

Over a four-year exposure period, the rate of ectopic pregnancy for women using a Copper T IUD was less than 1 per 1000 years of use. The cumulative 4-year probability of having an ectopic pregnancy while using the Copper T was 4 per 1000 women. These results are based on a study of 35,496 women with 38,064 years of use. Data on ectopic pregnancies in the United States provide a basis with which IUD experience may be compared. The National Hospital Discharge Survey shows a doubling in the number of ectopic pregnancies and in the incidence rates between 1965 and 1976. The relative risk of ectopic pregnancy among IUD users as compared with sexually active women not using the pill or sterilization may have been above 1 in 1965. In 1976, the relative risk is estimated to have been below 1. Compared with all woman-years of exposure, including women using contraceptive sterilization and the pill, the relative risk of extopic pregnancy to IUD users in 1976 was about 1. The IUD could not have been a major factor contributing to the recent doubling in the rate of ectopic pregnancy in the U.S.

Adult↗
PubMed1978

Long acting contraceptive implants. An analysis of menstrual bleeding patterns.

The menstrual patterns of women using subdermal implants of levonorgestrel and norgestrienone included in a double-blind clinical trial was evaluated by the method developed by the International Committee on Contraception Research. Women using Copper T200 randomly selected in the same clinics were used as controls. Both implant regimens were associated with a high frequency of reduced bleeding and norgestrel patients had also a high proportion of increased and irregular bleeding. Termination of use was associated to increased bleeding but not so much to reduced bleeding.

Adolescent↗
PubMed1977

Copper T 22oC.

Explore the source record for details and available documents.

Female↗