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Biomedical subjects

P D Darney

Publications and source records attributed to P D Darney.

At least 19 recordsLinked to original sources
PubMed1999

Condom practices of urban teens using Norplant contraceptive implants, oral contraceptives, and condoms for contraception.

OBJECTIVES: The availability of long-acting hormonal birth control methods has created new contraceptive options for adolescents. The purpose of this study was to determine whether teens initiating these methods use condoms less frequently than teens using oral contraceptive pills or condoms alone and may therefore be at an increased risk of acquiring sexually transmitted infections. STUDY DESIGN: To investigate ongoing condom behavior in teens using levonorgestrel (Norplant) contraceptive implants, oral contraceptives, and condoms alone, we examined data from a 2-year prospective cohort study of 399 urban teens. The study consisted of 3 clinic-based cohorts of adolescent female contraceptive users: Norplant contraceptive implants (n = 200), oral contraceptives (n = 100), and condoms alone (n = 99). Data were collected at an admission interview and at 1- and 2-year follow-up from method continuers. RESULTS: Norplant contraceptive implant users were less likely than oral contraceptive or condom users to report condom use at last sex or consistent condom use at 1- and 2-year follow-up. The implant group showed a significant decrease in condom use from admission to 2 years after method initiation. The proportion of implant users self-reporting new sexually transmitted infections at 2-year follow-up, however, was not significantly greater than that of oral contraceptive or condom users. CONCLUSIONS: Our findings indicate that teen users of Norplant contraceptive implants are less likely to use condoms than teens who choose oral contraceptives but, probably because of differences in sexual behavior, are no more likely to self-report sexually transmitted infections. Our findings also indicate that teens who choose oral contraceptives and condoms do not use them consistently enough to avoid pregnancies or sexually transmitted infections.

Adolescent↗
PubMed1997

Absorption kinetics of misoprostol with oral or vaginal administration.

OBJECTIVE: To compare the pharmacokinetics of vaginal and oral administration of the prostaglandin E1 analogue, misoprostol. METHODS: Twenty women received 400-micrograms doses of misoprostol either orally or as tablets placed in the vagina. Serum levels of principal metabolite, misoprostol acid, were measured at 7.5, 15, 30, 45, 60, 90, 120, and 240 minutes. The first ten women were pregnant and undergoing first-trimester abortions, and the last ten were not pregnant and had additional blood sampling at 360 minutes. We compared the pharmacokinetics of misoprostol acid after oral and vaginal administration. RESULTS: All 20 subjects completed the study. The maximum mean (+/- standard deviation [SD]) of misoprostol acid differed significantly between the oral and vaginal groups (277 +/- 124 compared with 165 +/d- 86 pg/mL, respectively; P = .03, analysis of variance), as did the mean +/- SD time to peak levels (34 +/- 17 compared with 80 +/- 27 minutes, respectively; P < .001) and areas under the misoprostol concentration versus time curve (mean +/- SD) up to 4 hours (n = 20,273.3 +/- 110.0 compared with 503.3 +/- 296.7 pg.hour/mL, respectively; P = .033) and up to 6 hours (n = 10, 300.0 +/- 103.3 compared with 956.7 +/- 541.7 pg.hour/mL, respectively; P = .029). The extent of absorption was highly variable among subjects in each group. CONCLUSION: There are significant differences in the pharmacokinetics of misoprostol administered by vaginal and oral routes that may explain the difference observed in clinical efficacy. Assuming that the pharmacologic effect of misoprostol is related to its concentration in the plasma, our observation of the prolonged serum concentrations in the vaginal group suggests that vaginal administration could be dosed at longer intervals than oral.

Abortifacient Agents, Nonsteroidal↗
PubMed1997

Medical abortion with oral methotrexate and vaginal misoprostol.

OBJECTIVE: To evaluate the safety and efficacy of oral methotrexate and vaginal misoprostol for medical abortion. METHODS: A prospective multicenter trial involved 300 women up to 49 days' gestation seeking elective abortion. Subjects received methotrexate 50 mg orally followed 5-6 days later by misoprostol 800 micrograms vaginally. The misoprostol dose was repeated if abortion did not occur. RESULTS: Complete abortion occurred in 273 of 299 women (91.3%; 95% confidence interval [CI] 87.5, 94.2%); one woman was lost to follow-up. Abortion occurred within 8 days of the methotrexate in 233 women (77.9%; 95% CI 72.8, 82.5%); the remaining 13.4% of women who aborted did so after a delay of 23.5 +/- 9.8 days (median 23 days, range 10-45). Vaginal bleeding lasted an average of 15 and 11 days in immediate and delayed-success abortions, respectively. Complete abortion rates decreased linearly with increasing body surface area. After methotrexate and misoprostol administration, nausea was reported in 37% and 33%, vomiting in 11% and 18%, diarrhea in 12% and 18%, and subjective fever or chills in 15% and 31% of subjects, respectively. CONCLUSION: Oral methotrexate followed by vaginal misoprostol is effective for abortion and represents an acceptable alternative to intramuscular methotrexate in regimens for medical abortion.

Abortifacient Agents, Nonsteroidal↗
PubMed1997

OC practice guidelines: minimizing side effects.

The side effects of oral contraceptives (OCs) can be minimized by appropriate OC selection. Side effects or perceived side effects that manifest themselves physically--e.g., weight gain, breakthrough bleeding (BTB), nausea, headache, breast tenderness, mood swings, acne, and hirsutism--are the most common causes of premature discontinuation of oral contraception. The relative androgenicity of the progestin component of combination OCs has become an important differential in selecting OC formulations. Several studies have indicated that preparations with less androgenic potential can minimize some of the "physical" side effects and adverse metabolic effects traditionally associated with oral contraception. Acne and hirsutism, common pre-existing conditions that are clearly related to the androgenicity of the progestin component, can be eliminated or improved by use of OCs with low androgenic activity. Many women perceive that OCs cause weight gain; although weight gain is to some extent androgen related, most studies comparing low-androgenic OCs with medium- or high-androgenic preparations have found little or no change in weight regardless of formulation. BTB, which usually subsides within a few months, is related to the dose, potency, and ratio of the estrogen and progestin in the OC formulation. Low-estrogen-dose OCs (< or = 35 micrograms ethinyl estradiol [EE]) containing less androgenic progestins are associated with bleeding patterns as acceptable as older low-estrogen-dose formulations. The same analysis found that smoking cigarettes promotes BTB in women who use OCs. There is no convincing evidence that the use of one progestin or another is less likely to cause or exacerbate headache; however, changing preparations sometimes reduces the incidence. Women with persistent headaches during the pill-free interval may benefit from a longer cycle of OC treatment. Nausea and breast tenderness are primarily estrogen-related effects; if a women experiences persistent nausea, switching to an OC formulation containing 20 micrograms EE may be appropriate as long as the patient is cautioned that BTB is more likely. Mood changes are a common, highly subjective complaint whose relationship to OC use is hard to assess. Concerns about the potentially deleterious effects of combination OCs on lipid/lipoprotein and carbohydrate metabolism have been substantially diminished by new epidemiologic findings relative to cardiovascular disease as well as by the development of low-androgenic progestins. Formulations containing these progestins lower LDL cholesterol and increase HDL cholesterol; they do not affect carbohydrate metabolism as much as older, more androgenic formulations.

Adolescent↗
PubMed1996

Serum concentrations of estradiol, progesterone, and levonorgestrel are not determinants of endometrial histology or abnormal bleeding in long-term Norplant implant users.

The objective of this study was to determine the relevance of serum estradiol, progesterone and levonorgestrel concentrations to endometrial histology and uterine bleeding associated with long-term Norplant implants use. Eighteen five-year users of Norplant implants had endometrial biopsies and determinations of serum estradiol, progesterone and levonorgestrel concentrations. Correlations among these factors and uterine bleeding were calculated. Proliferative endometrium (but not sex steroid levels) was associated with abnormal bleeding. Neither ovarian steroid nor levonorgestrel concentrations was a predictor of abnormal bleeding. Hyperplastic changes were not seen even with high estradiol and low levonorgestrel levels.

Adult↗
PubMed1996

Methotrexate and misoprostol for early abortion: a multicenter trial. I. Safety and efficacy.

A prospective trial was conducted including 300 pregnant women seeking elective abortion to evaluate the safety and efficacy of methotrexate and misoprostol for abortion at < or = 56 days gestation. Subjects received methotrexate 50 mg/ m2 intramuscularly followed 7 days later by misoprostol 800 micrograms vaginally. The misoprostol dose was repeated the next day if the abortion did not occur. Outcome measures included successful abortion (complete abortion without requiring a surgical procedure), duration of vaginal bleeding, and side effects. Complete abortion occurred in 263/ 300 (87.7%, 95% CI 83.4, 91.2%) patients. The complete abortion rate was higher for early gestations: 183/202 (90.6%, 95% CI 85.7, 94.2%) at < or = 49 days gestation, and 80/98 (81.6%, 95% CI 72.5, 88.7%) from 50-56 days gestation (p = 0.038). Abortion occurred in the 24 hours following the initial or repeat misoprostol dose (immediate success) in 65.0%; the remaining 22.7% of women who aborted did so after a delay of 23.6 +/- 9.1 (mean +/- standard deviation) days. Vaginal bleeding lasted 14 +/- 7 days and 11 +/- 9 days in immediate success and delayed success patients, respectively. Overall, 69.7%, 87.7%, and 91.7% of patients had passed the pregnancy by 14, 28, and 35 days, respectively, after receiving methotrexate. Methotrexate and misoprostol side effects were minimal. This treatment regimen offers an alternative to surgical abortion or the use of antiprogestins and prostaglandin for medical abortion.

Abortifacient Agents, Nonsteroidal↗
PubMed1995

The androgenicity of progestins.

All steroid hormones are structurally similar, but relatively minor differences cause profound alterations in biochemical activity. The 21-carbon series (pregnane nucleus) includes the corticoids and the true progestins (e.g., medroxyprogesterone acetate). The 19-carbon series (androstane nucleus) includes all the androgens, among them the progestins used in most oral and parenteral contraceptives. The removal of carbon 19 from testosterone changes the major hormonal effect from androgenic to progestogenic, but these "19-nor" steroids retain varying degrees of androgenic activity. (They can also have limited estrogenic activity, but this is insignificant at the low doses used for contraception.) Some of the 19-nortestosterone progestins are metabolized to other compounds (e.g., norethynodrel, ethynodiol diacetate, and lynestrenol to norethindrone), and some (levonorgestrel, desogestrel) are active unchanged. The lingering androgenic effects of 19-nor progestins are dose-related, opposed by estrogen, and are manifested metabolically (e.g., glucose tolerance, lipoprotein synthesis) and symptomatically (e.g., acne, weight gain). The effect of 19-nortestosterones on lipoproteins prompted the development of less androgenic compounds, but the obvious benefit of the new progestins (desogestrel, gestodene, norgestimate) is a reduction in the symptoms associated with the androgenicity of the older compounds. Mitigation of androgenic effects on lipoprotein and carbohydrate metabolism could have long-term benefits, especially for women who are at risk of arteriosclerotic vascular disease; however, these effects remain to be epidemiologically demonstrated.

Androgens↗
PubMed1994

Hormonal implants: contraception for a new century.

Subdermal implants are contraceptive systems that release low, stable amounts of synthetic progestins from Silastic or other materials for periods of months to several years. Unlike other hormonal delivery systems, they do not cause unnecessary peaks in progestin levels and do not use estrogens, and thus their health risks are minimal. Norplant has been studied more extensively than any other subdermal contraceptive implant. More than 60,000 women have participated in clinical trials, which demonstrated that this approach is one of the most effective reversible contraceptive methods available (1% pregnancy rate in 5-year users). The implant also reduces the incidence of ectopic pregnancy to a level much below noncontraceptive users and about equivalent to TCu380A intrauterine device users. Exposure to the sustained, low dose of levonorgestrel delivered by Norplant has shown only minor metabolic changes. Side effects are minor but often bothersome, causing some discontinuation of the method. First-year continuation rates range from 76% to 90%. Fertility return after discontinuation is prompt. Difficulty in removal of the implant capsules by the less experienced practitioner has motivated researchers to develop systems that are easier to use, less obvious under the skin, and biodegradable. The Norplant 2 system is faster, easier, and less painful to insert and remove. Implants under investigation release desogestrel and other progestins; Capronor and subdermal norethindrone pellets are biodegradable systems.

Contraceptive Agents, Female↗
PubMed1993

Methotrexate and misoprostol for early abortion.

Methotrexate is cytotoxic to trophoblast and, in low doses, has minimal side effects. It is used to treat both gestational trophoblastic neoplasia and ectopic pregnancy. The cytotoxic effects of methotrexate on intrauterine trophoblast should be equivalent. To test this hypothesis, ten pregnant women, < 8 weeks' gestation were treated with methotrexate 50 mg/m2 intramuscularly followed 3 days later by misoprostol, a prostaglandin E1 analogue. The first 4 patients received misoprostol 600 micrograms orally; none aborted soon after the misoprostol. Two patients aborted 25 and 26 days after the methotrexate injection and two elected a suction abortion after 14 days (one by choice and one because the pregnancy was still viable). The last 6 patients received misoprostol 800 micrograms vaginally and aborted within 3-8 hours. One patient had an incomplete abortion requiring a suction curettage 34 days after the misoprostol. Vaginal bleeding for these 6 patients lasted an average of 29 +/- 11 days (range, 12-42 days). No methotrexate side effects were observed. Vaginal misoprostol (800 micrograms) was significantly more effective (p = 0.005) than oral misoprostol (600 micrograms) in effecting abortion after intramuscular methotrexate.

Abortion, Induced↗
PubMed1993

Contraceptive choices for behaviorally disordered women.

Women with psychologic disturbances of depression, anxiety, or thought disorganization pose a special management problem when providing a safe and effective means of contraception. The difficulty is compounded by the fact that many mentally disturbed women also abuse drugs. Therefore, providing contraception to the many types of behaviorally disturbed women requires the full range of contraceptive options and protection from sexually transmitted diseases. When compliance can be assured, oral contraceptives are the preferred method. When compliance is questionable, progestin implants or injections may be tried. However, progestin-only preparations are associated with several side effects, including worsening of mood in depressive patients.

Contraception↗
PubMed1992

Evaluation of a 1-year levonorgestrel-releasing contraceptive implant: side effects, release rates, and biodegradability.

OBJECTIVE: To determine the release rates, effects on ovulation, and side effects of two lengths of a biodegradable, subdermal contraceptive implant containing levonorgestrel in a caprolactone capsule. DESIGN: Phase II randomized clinical trial. SETTING: Public family planning clinic at an urban general hospital. PARTICIPANTS: Forty-eight healthy, parous, ovulating volunteers. INTERVENTION: Subjects were randomly assigned either a 2.5- or a 4.0-cm contraceptive capsule that was worn under the skin of the upper arm for 1 year if not removed earlier for other reasons. MAIN OUTCOME MEASURES: Serum concentrations of levonorgestrel, progesterone, estradiol, and lipoproteins were measured as were metabolic parameters. Vaginal bleeding and other side effects were recorded. After implant removal, remaining levonorgestrel, capsule viscosity, and molecular weight were measured. RESULTS: The 4-cm implant provided serum concentrations of levonorgestrel ranging from 0.65 ng/mL shortly after insertion to 0.20 ng/mL at 12 months, but the 2.5-cm implant resulted in levels too low for contraception. The 4-cm implant suppressed ovulation in approximately 80% of cycles over 1 year of use, but the 2.5-cm implant failed to suppress ovulation. The implants were rapidly and easily inserted and removed. They retained structural integrity through 1 year of use. Of 48 subjects, 32 had abnormal bleeding patterns; the mean number of days of bleeding per month was 7 with 23 days between episodes. Women using capronor maintained normal metabolic parameters except that low-density lipoprotein decreased slightly. CONCLUSIONS: The 4.0-cm implant is a promising contraceptive. There were no important metabolic effects, but there were bothersome minor side effects typical of progestin-only contraception.

Abdominal Pain↗
PubMed1992

AIDS (HIV) risk assessment in an inner-city women's clinic.

Risk assessment and antibody testing are potential modalities through which interventions to reduce heterosexual and perinatal transmission of human immunodeficiency virus (HIV) can occur. More than 98% of women attending inner-city adult gynecology, adult contraception and teen family planning clinics successfully completed self-administered HIV (AIDS) risk assessment questionnaires and received individual counseling, risk-reduction education and referral for antibody testing. Fourteen percent of the women (671/4,802) reported at least one HIV risk factor. Multiple sexual partners and intravenous drug use were the most commonly reported HIV risk factors in this population.

AIDS Serodiagnosis↗
PubMed1991

Subdermal progestin implant contraception.

Sustained-release progestin contraceptives are a new approach to meeting a worldwide need for more effective and acceptable birth control. These contraceptive systems provide low, stable levels of synthetic progestins for periods of months to several years. Unlike earlier injectable and oral contraceptives, they do not cause peaks in progestin levels beyond those required for effective contraception, nor do they employ estrogens. For these reasons, sustained-release progestin systems are without some of the health risks attributed to birth control pills, and they are more effective, as well as easy to use, and completely reversible. They share common side effects, the most frequent of which is irregular menstrual bleeding caused by the erratic shedding of hypotrophic endometrium. Despite this and other minor side effects, most users find the sustained-release systems acceptable alternatives to other methods of contraception. Permanent or biodegradable subdermal implants, injections, intrauterine and intracervical devices, and vaginal rings are all employed as delivery systems for contraceptive progestins. The Norplant (Wyeth Ayerst, Radnor, PA) system, consisting of six silastic tubes filled with levonorgestrel and implanted under the skin, was recently approved by the US Food and Drug Administration and is already used by more than a half million women worldwide. The other sustained-release systems are in various stages of development, at least several years away from general use. When these new methods complete clinical trials, women will be able to choose from among implants, injections, or pellets with various durations of action, all providing convenient, highly effective contraception with low risk to health.

Biodegradation, Environmental↗
PubMed1990

Uterine perforation during second-trimester abortion by cervical dilation and instrumental extraction: a review of 15 cases.

Review of the records of 15 women who had uterine perforations at the time of second-trimester abortion by dilation and evacuation showed that unexpected pain (but not excessive bleeding) was the most prominent sign. All patients required laparotomy, but in no case was laparotomy necessary as an emergency procedure. Laparoscopy was not helpful. Two-thirds had bowel injuries and two required hysterectomy. Errors in estimating gestational duration, inadequate cervical dilation, and failure to use sonography characterized these complicated cases.

Abortion, Induced↗
PubMed1989

Clinical evaluation of the Capronor contraceptive implant: preliminary report.

Capronor, a single-capsule, biodegradable, subdermal contraceptive that releases levonorgestrel over a 12- to 18-month period, has been evaluated in 48 healthy women, ages 18 to 40 years. Sixteen participants received a 2.5 cm capsule (12 mg of levonorgestrel), and 32 received a 4.0 cm capsule (21.6 mg of levonorgestrel). Serum levonorgestrel levels were significantly lower in the 2.5 cm group. Ovulation occurred in all cycles in the 2.5 cm group and in 26.3% of cycles in the 4.0 cm group. Levonorgestrel levels with the shorter capsule were too low for reliable contraception in all users, and 4 cm may be a minimal functional length. Bleeding patterns were regular in most women who ovulated and irregular in most remaining subjects. It is assumed that changes in cervical mucus and the endometrium contributed to effective contraception despite the frequency of ovulation.

Administration, Cutaneous↗