Sequential contraceptives

NB There is also conclusive evidence that these agents have a protective effect against cancers of the ovary and endometrium) Oral contraceptives, sequential (Suppl. 7 1987)... 

In addition, several progestins have been used in the absence of estrogens for purposes of contraception. It is clear that they owe their efficacy, which is not as high as that of the combination or sequential treatments, to some mechanism other than inhibition of ovulation. These are not yet represented by marketed entities for that indication. 

Sequential oral contraceptives (see also Oestrogens, progestins and eombinations)... 

Dimethisterone (see also Progestins Sequential oral contraceptives... 

Oral contraceptives, investigational (see Combined oral contraceptives) Oral contraceptives, sequential (see Sequential oral contraceptives) Orange I... 

Conflicting data concerning the effects of oral contraceptives on carbohydrate metabolism have been presented the effects are probably clinically insignificant. However, estrogen hormone replacement therapy with a sequential-type product containing mestranol and norethisterone caused significantly impaired glucose tolerance (30). 

Both sequential and non-sequential types of oral contraceptives impair the absorption of polyglutamic folate but not that of monoglutamic folate the change can result in megaloblastic anemia in predisposed subjects, for example those with celiac disease or having a deficient diet (182). 

There has been some indication that hormonal contraceptives may lead to certain forms of cancer. Some early versions of the pill were believed to cause tumors of the endometrium of the uterus. Early forms that were sequential in nature may have caused... 

While numerous studies have evaluated the effect of oral contraceptives and postmenopausal hormone replacement on drug clearance, many were flawed by poor study design. Table 21.1 lists studies that were of crossover or sequential design such that each subject was evaluated in the contraceptive phase and placebo phase. These study designs minimize the effect of interindividual variability. In most studies there was no effect of hormonal therapy on drug metabolism, but in some there were interactions that inhibited or increased the metabolism of concurrently administered drugs. 

Some of the areas where interfacial protein layers dominate the boundary chemistry are reviewed, and we introduce some nondestructive armlytical methods which can be used simultaneously and/or sequentially to detect and characterize the microscopic amounts of matter at protein or other substrates which spontaneously acquire protein conditioning films. Examples include collagen and gelatin, synthetic polypeptides, nylons, and the biomedically important surfaces of vessel grafts, skin, tissue, and blood. The importance of prerequisite adsorbed films of proteins during thrombus formation, cell adhesion, use of intrauterine contraceptives, development of dental adhesives, and prevention of maritime fouling is discussed. Specifics of protein adsorption at solid/liquid and gas/liquid interfaces are compared. 

The hostility of the thickened cervical mucus to sperm penetration has been used as a means to achieve contraception, and low-dose oral contraceptives depend largely on this condition for their effectiveness in fertility controlJ Sequential oral contraceptives do not affect mucus and like estrogen, may even increase sperm penetration. 

In this list the outstanding fact is the almost perfect record of contraception for each. For purposes of contraception, therefore, there appears to be no differentiation between them despite divergences in molecular structure. The lowest daily dose listed is that of 1 mg. for SC-11800, which is compound X of Figure 2. But the sequential administration of Chlormadinone (compound VIII of Figure 3) and of Orthonovum (compound I of Figure 2) involves... 

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