Oral contraceptives and cycle control: A critical review of the literature

Abstract

Control of spotting and breakthrough bleeding and absence of withdrawal bleeding, collectively termed cycle control, is the single most important determinant of whether a new user of oral contraceptives (OCs) will continue this method. However, information about different OC preparations and how they affect such problems, including the effects of progestogen and estrogen phasing and the components of these hormones, is scant and confusing. Studies cited in this report reveal highly variable rates of bleeding problems in women taking OCs: after 6 months of OC use, the prevalence of spotting varied between 0% and 8.5%; of breakthrough bleeding, 0% and 12.2%; and of amenorrhea, 0% and 5.8%. At least some of this variation is attributable to differing study populations and cultures, study designs, and the manner in which data were collected and reported. However, methodologic weaknesses were common, often involving lack of randomization and blinding, and attrition rates were high. Despite these limitations, it is clear that the frequency of bleeding problems decreases with continuing use of OCs, emphasizing the need for patient reassurance about the transient nature of these problems. In addition, gestodene-containing preparations appear to offer better cycle control than do desogestrel-containing preparations and levonorgestrel-containing preparations better control than norethindrone-containing preparations. However, the strongest lesson to emerge is the need for more rigorous studies to adequately address questions of comparative bleeding problems, particularly with newer triphasic formulations. These conclusions underscore the importance of counseling new OC users about the possibility of bleeding problems, reassuring them that most such problems are temporary, and, that if compliance is maintained, these will not impair contraceptive efficacy.

Hormonal Contraception in Adolescents

“…[42] Other studcially when using 20μg pills on a long-term basis. [35] If this is a ies published at the same time reported similar results. [43][44][45] In one cause for concern, after ruling out pregnancy, a higher dose pill study, the highest risk with desogestrel was seen in the youngest can be substituted, or a brief course of supplemental estrogen can age groups (15-to 19-year-olds and 20-to 24-year-olds), in which be taken.…”

Tumour induction by activated abl involves tyrosine phosphorylation of the product of the cbl oncogene.

“…Indeed, recent evidence indicates that overexpression of c-abl inhibits cell growth by causing cell cycle arrest (Sawyers et al, 1994). However, alterations by retroviral transduction, or chromosomal translocations to the bcr gene in Philadelphia chromosome-positive human leukaemias, converts abl to an oncogenic and highly active cytoplasmic tyrosine kinase (reviewed by Kurzrock et al, 1988;Rosenberg and Witte, 1988;Sawyers, 1992;Wang, 1993). Furthermore, a functional tyrosine kinase domain is essential for transformation, and a direct correlation has been shown between kinase activity and the oncogenic potency of bcr-abl and v-abl products (Lugo et al, 1990).…”

The fiction of an ideal hormonal contraceptive

“…So-called nuisance side-effects, especially bleeding irregularities such as breakthrough bleeding and amenorrhea, can lead to discontinuation rates of up to 50% in new users before the end of their first year of usage [10][11][12]. In 1995, Rosenberg and co-workers [4] analyzed COC usage in over 6500 women from five countries in Europe (Denmark, France, Italy, Portugal and the United Kingdom).…”