Evidence-based case review. Contraception for adolescents

Physiologically-based pharmacokinetic modeling of prominent oral contraceptive agents and applications in drug-drug interactions

Considerable interest remains across the pharmaceutical industry and regulatory landscape in capabilities to model oral contraceptives (OCs), whether combined (COCs) with ethinyl estradiol (EE) or progestin-only pill. Acceptance of COC drug-drug interaction (DDI) assessment using physiologically-based pharmacokinetic (PBPK) is often limited to the estrogen component (EE), requiring further verification, with extrapolation from EE to progestins discouraged. There is a paucity of published progestin component PBPK models to support the regulatory DDI guidance for industry to evaluate a new chemical entity's (NCE's) DDI potential with COCs. Guidance recommends a clinical interaction study to be considered if an investigational drug is a weak or moderate inducer, or a moderate/strong inhibitor, of CYP3A4. Therefore, availability of validated OC PBPK models within one software platform, will be useful in predicting the DDI potential with NCEs earlier in the clinical development. Thus, this work was focused on developing and validating PBPK models for progestins, DNG, DRSP, LNG, and NET, within Simcyp, and assessing the DDI potential with known CYP3A4 inhibitors (e.g., ketoconazole) and inducers (e.g., rifampicin) with published clinical data. In addition, this work demonstrated confidence in the Simcyp EE model for regulatory and clinical applications by extensive verification in 70+ clinical PK and CYP3A4 interaction studies. The results provide greater capability to prospectively model clinical CYP3A4 DDI with COCs using Simcyp PBPK to interrogate the regulatory decision-tree to contextualize the potential interaction by known perpetrators and NCEs, enabling model-informed decision making, clinical study designs, and delivering potential alternative COC options for women of childbearing potential.

Exploring the why: risk factors for HIV and barriers to sexual and reproductive health service access among adolescents in Nigeria

BACKGROUND

Early sexual debut, low educational attainment, history of rape and transactional and intergenerational sex have been associated with HIV infection among Nigerian adolescents, especially females. We sought to understand the "why", and how to mitigate against these determinants and barriers to addressing adolescent sexual and reproductive health (SRH) and HIV prevention needs.

METHODS

This qualitative study generated data from 49 focus group discussions with male and female adolescents living with and without HIV, healthcare workers, members of civil society organizations working with young people, and parents of adolescents living with HIV. Participants were recruited from all six geopolitical zones in Nigeria. Data was analysed with ATLAS.ti software. Hermeneutic units were created, and codes developed from focus group transcripts. Network View Manager was used to create maps of codes, memos and quotations, and relevant quotes were retrieved from transcripts.

RESULTS

Four major themes were identified, relating to individual, parental, community and government roles in reducing the risk of HIV and unplanned pregnancy among adolescents in Nigeria. Individual factors influencing sexual risk behaviours of adolescents include peer pressure, poor risk perception for HIV, and misconceptions about the efficacy of contraceptives and condoms. Respondents entrusted State responsibilities such as facilitation of HIV-affected adolescents' access to education, rather, to individuals, parents and the community; and placed the blame for rape on rape survivors. Findings also highlighted the inadequacy of health systems to address adolescents' needs for treatment of sexually transmitted infections and to provide appropriate education on secondary HIV prevention for those living with HIV.

CONCLUSION

Rigorous studies are needed to understand dynamics between adolescents' risk behavior, HIV risk perception, parental roles in mitigating HIV risk in adolescents, and the role of communities and government in HIV prevention and treatment for adolescents in Nigeria.

Changes in young women’s contraceptive use in the Netherlands: findings from three sex under the age of 25 surveys

Prevention of unintended pregnancy among adolescents and young adults under 25 years is pivotal from an individual as well as societal perspective. In the USA, the use of long-acting reversible contraceptive (LARC) has been shown to increase, with no or little change in the use of short-acting reversible contraceptive (SARC). We assessed trends in no contraceptive, SARC, and LARC use by young women, aged between 12 and 25 years, and differences in trends within demographic groups (age, religion, ethnic background, and educational level) among these young women in the Netherlands. Data of sexually active young women aged 12–25 years from three cross-sectional representative surveys, 2005, 2012, and 2017, were used for this study. In total, 11,229 Dutch young women were included with a median age of 20 years (interquartile range 18–23 years). Overall, the proportion of young women using SARC decreased significantly between 2005 and 2017 from 88 to 76%. LARC use increased significantly between 2005 and 2017 from 3 to 16%. These trends varied by religious groups and educational level, emphasizing potential for tailored preventative measures for these groups. A shift towards LARC use might eventually lead to a further decrease in unwanted pregnancy and potentially abortion because of the lower risk of user errors.

Prevalence of pregnancy experiences and contraceptive knowledge among single adults in a low socio-economic suburban community in Kuala Lumpur, Malaysia

BACKGROUND

This study aimed to investigate the prevalence of pregnancy experience and its association with contraceptive knowledge among single adults in a low socio-economic suburban community in Kuala Lumpur, Malaysia.

METHODS

A cross-sectional survey was conducted in 2012 among the Kerinchi suburban community. Of the total 3,716 individuals surveyed, young single adults between 18 and 35 years old were questioned with regard to their experience with unplanned pregnancy before marriage. Contraceptive knowledge was assessed by a series of questions on identification of method types and the affectivity of condoms for the prevention of sexually transmitted diseases.

RESULTS

A total of 226 female and 257 male participants completed the survey. In total, eight female (3.5%) participants reported experience with an unplanned pregnancy before marriage, and five male (1.9 %) participants had the experience of impregnating their partners. The participants had a mean total score of 3.15 (SD = 1.55) for contraceptive knowledge out of a possible maximum score of five. Female participants who had experienced an unplanned pregnancy had a significantly lower contraceptive knowledge score (2.10 ± 1.48) than who had never experienced pregnancy (3.30 ± 1.35), p<0.05. Likewise, male participants who had experienced impregnating their partners had a significantly lower contraceptive knowledge score (1.60 ± 1.50) than those who did not have such experience (3.02 ± 1.59), p<0.05.

CONCLUSION

The results showed evidence of premarital unplanned pregnancy among this suburban community. The low level of contraceptive knowledge found in this study indicates the need for educational strategies designed to improve contraceptive knowledge.

Contraceptive care for the adolescent

Despite recent improvements in rates of teen pregnancy, abortion, birth,and contraceptive use, effective contraceptive counseling for adolescents should be a high priority for the primary care provider in the office setting. Adolescent psychosocial risk screening and appropriate counseling about sexual decision-making is necessary. Contraceptive services visits include, relevant history, limited physical examination, provision of information, anticipatory guidance about sexual behaviors, and the provision of contraceptive methods. Teens should always be encouraged to use a male condom during sex to reduce STI risk. A variety of barrier and hormonal contraceptive methods are available for the adolescent population. Education about and provision of EC is effective in reducing the rate of unintended pregnancy and abortion in the United States. Contraceptive care for adolescents is a rewarding experience for primary care providers.