What are the risks of third-generation oral contraceptives? Are third-generation oral contraceptives safe?

Hypericum perforatum: pharmacokinetic, mechanism of action, tolerability, and clinical drug-drug interactions

Hypericum perforatum (HP) belongs to the Hypericaceae family and is one of the oldest used and most extensively investigated medicinal herbs. The medicinal form comprises the leaves and flowering tops of which the primary ingredients of interest are naphthodianthrones, xanthones, flavonoids, phloroglucinols (e.g. hyperforin), and hypericin. Although several constituents elicit pharmacological effects that are consistent with HP's antidepressant activity, no single mechanism of action underlying these effects has thus far been found. Various clinical trials have shown that HP has a comparable antidepressant efficacy as some currently used antidepressant drugs in the treatment of mild/moderate depression. Interestingly, low-hyperforin-content preparations are effective in the treatment of depression. Moreover, HP is also used to treat certain forms of anxiety. However, HP can induce various cytochrome P450s isozymes and/or P-glycoprotein, of which many drugs are substrates and which are the main origin of HP-drug interactions. Here, we analyse the existing evidence describing the clinical consequence of HP-drug interactions. Although some of the reported interactions are based on findings from in vitro studies, the clinical importance of which remain to be demonstrated, others are based on case reports where causality can, in some cases, be determined to reveal clinically significant interactions that suggest caution, consideration, and disclosure of potential interactions prior to informed use of HP.

Molecular medicine and population control

As we uncover the physiological and molecular mechanisms behind human reproduction, we gain the potential to exert more control over our reproductive capabilities. In the past two decades, the prospects for 'infertile' women to bear children, or 'sterile' men to father them, have improved dramatically; recently, women have given birth in their sixties, well beyond their natural menopause. Thanks to developments in contraception, couples can now enjoy an active sex-life without a significant risk of pregnancy, and more accurately control the size and timing of their families. But these new freedoms have a price: they also have the potential to cause demographic distortions, medical harm to individuals and abuse of human rights.

First-time use of newer oral contraceptives and the risk of venous thromboembolism

Recent epidemiologic studies reported that the risk of venous thromboembolism (VTE) was higher with the use of the newer third generation oral contraceptives than with second generation agents. Although the overall findings of these studies are similar, the results, as they relate to patterns and duration of oral contraceptive use particularly among first-time users, are inconsistent. We reanalyzed data from the Transnational case-control study to assess the risk of VTE associated with first-time use of oral contraceptives as a function of its duration of use. Over the period 1993 to 1995, 471 cases of venous thromboembolism were identified in Germany and the United Kingdom. For each case, up to four controls were obtained, for a total of 1772 controls. Data on oral contraceptive use and confounding variables, including data on sociodemographic, lifestyle, medical history, and family history of disease, were obtained by interview. Data analysis was based on the 105 cases and 422 controls who were first-time users of second or third generation agents, or never users of oral contraception. Rate ratios, adjusted for confounders and approximated by odds ratios, were estimated as a continuous function of duration of oral contraceptive use by logistic regression and quadratic spline models. We found, for first-time users, that the adjusted rate ratio of VTE as a function of the duration of oral contraceptive use is essentially identical for second and third generation pills relative to never users. This rate ratio increases to around 10 in the first year of use and decreases to around two after 2 years of use, remaining at this risk level thereafter for both second and third generation agents. We conclude that second and third generation agents are associated with identical risks of venous thromboembolism when they are prescribed to women who are using oral contraceptives for the first time ever.