Contraception
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Comparative Study Clinical Trial
Pharmacokinetics of levonorgestrel and ethinylestradiol in 14 women during three months of treatment with a tri-step combination oral contraceptive: serum protein binding of levonorgestrel and influence of treatment on free and total testosterone levels in the serum.
The pharmacokinetics of levonorgestrel (LNG) and ethinylestradiol (EE2) were determined in 14 healthy women (age 18 to 27 years) during a treatment period of three months with a tri-step combination oral contraceptive (Triquilar). Prior to this treatment period, the same women received a single administration of a coated tablet containing 0.125 mg LNG together with 0.03 mg EE2. There was a washout phase of one week between both treatments. ⋯ There was no difference in corresponding pharmacokinetic parameters and in the serum protein binding of LNG at the end of cycles one and three. On the last day of treatment cycles one and three, the AUC(0-4h) values of EE2 were 331.2 and 369.6 pg x ml-1 x h, respectively, which corresponds to an about 11-24% increase as compared to single dose administration, where an AUC(0-4h) value of 298.3 pg x ml-1 x h was found. Total and free testosterone concentrations decreased during treatment cycles one and three by about 41% and 55%, respectively, compared with the corresponding values measured prior to treatment.
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A risk-benefit analysis of five alternative approaches to fertility control among US women over the age of 30 was performed: tubal ligation, vasectomy, intrauterine device, barrier method (condom), and combined oral contraceptives. Taken into account were age-specific probabilities of contraceptive failure, fecundability, spontaneous abortion, reproductive mortality (ectopic pregnancy, delivery, or induced abortion), life table mortality, and mortality from specific cancer sites (ovarian, endometrial, breast, and prostate) and cardiovascular disease. Relative to women using no contraceptive precautions, the use of any method of contraception between the ages of 30 and 50 was associated with net benefit in terms of averted deaths. ⋯ Other methods continued to be associated with net benefit, ranging from 130 to 360 deaths averted per 100,000 users. It was concluded that the non-reproductive risks and benefits of contraceptive methods continue to be relevant long after the reproductive years. The balance of risks and benefits may differ in other countries with different cause-specific and life table mortality rates.
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Norplant implants were removed from fifty (50) patients using a modified approach to Norplant implant removal (Emory Method). Eighty-eight percent (88%) of the removals were accomplished in less than 10 minutes using this technique. The average time for removal of Norplant implants from 50 women included in the current study was 8 minutes. ⋯ More anesthesia, a slightly longer incision and vigorous disruption of the tissue encapsulation surrounding the implants are recommended. The Emory Method is fast, safe and easy to perform. It has been successfully taught to over twenty-five clinicians.
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Reports of the phase III clinical trials on four combined progestogen-estrogen once-a-month injectable contraceptives, Deladroxate, Cyclofem, Mesigyna and Chinese Injectable No. 1, are reviewed focussing on efficacy and reasons for discontinuation. Deladroxate, currently used in many Latin American countries has proved to be highly effective and well accepted. However, this combination was withdrawn by the original manufacturer because the progestogen component of this drug induced a high number of breast cancers in dogs and very curious pituitary hyperplasia in rats. ⋯ After doubling the dose in the first month of use, the efficacy was satisfactory. It was found that all monthly injectable contraceptives provided better cycle control than the every 3 months depot-medroxyprogesterone acetate, although abnormal bleeding was still the main drug-related complaint and reason for discontinuation. Missed appointment is another reason for discontinuation which might reflect the problem of frequent injection schedule, thus indicating the need for proper selection of the users and good counselling.
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Earlier studies on the rat and the monkey had demonstrated that an injection of styrene maleic anhydride (SMA) in a solvent vehicle of dimethyl sulphoxide (DMSO) into the lumen of the vas deferens is toxicologically safe and has contraceptive action. Phase I clinical trial was therefore undertaken on 38 male volunteers giving varying doses of SMA, ranging between 5 mg and 140 mg, into each vas deferens. ⋯ That the compound is within the vas deferens lumen during the period of the safety assessment is inferred from the effect on the spermatozoa count in ejaculates which reach azoospermic levels in the higher dose ranges. The treatment is well tolerated with only minimal side effects in a few cases and no long-term adverse effects.