Pharmacokinetics of the levonorgestrel-only emergency contraceptive regimen among normal-weight, obese and extremely obese users: a pilot study

Progestin therapy for obese women with complex atypical hyperplasia: levonorgestrel-releasing intrauterine device vs systemic therapy

BACKGROUND

Though hysterectomy remains the standard treatment for complex atypical hyperplasia, patients who desire fertility or who are poor surgical candidates may opt for progestin therapy. However, the effectiveness of the levonorgestrel-releasing intrauterine device compared to systemic therapy in the treatment of complex atypical hyperplasia has not been well studied.

OBJECTIVE

We sought to examine differences in treatment response between local progestin therapy with the levonorgestrel-releasing intrauterine device and systemic progestin therapy in women with complex atypical hyperplasia.

METHODS

This single-institution retrospective study examined women with complex atypical hyperplasia who received progestin therapy between 2003 and 2018. Treatment response was assessed by histopathology on subsequent biopsies. Time-dependent analyses of complete response and progression to cancer were performed comparing the levonorgestrel-releasing intrauterine device and systemic therapy. A propensity score inverse probability of treatment weighting model was used to create a weighted cohort that differed based on treatment type but was similar with respect to other characteristics. An interaction-term analysis was performed to examine the impact of body habitus on treatment response, and an interrupted time-series analysis was employed to assess if changes in treatment patterns correlated with outcomes over time.

RESULTS

A total of 245 women with complex atypical hyperplasia received progestin therapy (levonorgestrel-releasing intrauterine device n = 69 and systemic therapy n = 176). The mean age and body mass index were 36.9 years and 40.0 kg/m², respectively. In the patient-level analysis, women who received the levonorgestrel-releasing intrauterine device had higher rates of complete response (78.7% vs 46.7%; adjusted hazard ratio, 3.32; 95% confidence interval, 2.39-4.62) and a lower likelihood of progression to cancer (4.5% vs 15.7%; adjusted hazard ratio, 0.28; 95% confidence interval, 0.11-0.73) compared to those who received systemic therapy. In particular, women with class III obesity derived a higher relative benefit from levonorgestrel-releasing intrauterine device therapy in achieving complete response compared to systemic therapy: class III obesity, adjusted hazard ratio 4.72, 95% confidence interval 2.83-7.89; class I-II obesity, adjusted hazard ratio 1.83, 95% confidence interval 1.09-3.09; and nonobese, adjusted hazard ratio 1.26, 95% confidence interval 0.40-3.95. In the cohort-level analysis, the obesity rate increased during the study period (77.8% to 88.2%, 13.4% relative increase, P = .033) and levonorgestrel-releasing intrauterine device use significantly increased after 2007 (6.3% to 82.7%, 13.2-fold increase, P < .001), both concomitant with a higher proportion of women achieving complete response (32.9% to 81.4%, 2.5-fold increase, P = .005).

CONCLUSION

Our study suggests that local therapy with the levonorgestrel-releasing intrauterine device may be more effective than systemic therapy for women with complex atypical hyperplasia who opt for nonsurgical treatment, particularly in morbidly obese women. Shifts in treatment paradigm during the study period toward increased levonorgestrel-releasing intrauterine device use also led to improved complete response rates despite increasing rates of obesity.

Levonorgestrel emergency contraception and bodyweight: are current recommendations consistent with historic data?

Objective

To assess the consistency between current recommendations that women of body weight (BW) or body mass index (BMI) above a defined threshold should use a double dose of levonorgestrel (LNG) for emergency contraception (EC) and observed frequency of pregnancy in historic studies of single-dose LNG for EC.

Methods

We applied double dose recommendation criteria to individual participant level data from three historic studies of the WHO’s Human Reproductive Program to categorize subjects into single dose-recommended (SDR) and double dose-recommended (DDR) groups and compared the latter to the former using pregnancy risk ratios (RR).

Results

A total of 5859 subjects with 59 pregnancies made up the full dataset. Depending on the recommendation source (USA or UK) and inclusion or exclusion of heavy outlier data, DDR criteria were satisfied by 3.7% to 18.9% of subjects. Pregnancy proportions were mostly lower in DDR than in SDR subjects, with risk ratio estimates ranging from zero to 1.17, exceeding unity only when the USA criterion was used with outliers included. DDR subjects had a significantly lower relative frequency of pregnancy than SDR subjects when the UK criteria were used and outliers excluded (RR = 0.17 [95% CI: 0.04; 0.70], p = .0024).

Conclusions

Our findings are consistent with the notion that there is no real loss of pregnancy control with single-dose LNG-EC in high-BMI and/or high-BW users, and today’s double dose recommendations were prematurely issued and remain questionable.

Levonorgestrel emergency contraception and bodyweight

Objectives: Emergency contraception (EC) provides an opportunity to avoid an unwanted pregnancy following unprotected sexual intercourse (UPSI), failure of a regular contraceptive method, or after sexual assault. Two main methods are currently available: oral pills or the copper-T intrauterine device. In recent years there has been some debate regarding the efficacy of oral therapy in obese women. In this brief commentary we review new evidence, published after the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) referral of 2014, relating to the effect of obesity on the pharmacokinetics and clinical efficacy of levonorgestrel EC in light of some of the concerns that have been raised. Methods: A PubMed literature search ("levonorgestrel" and "emergency contraception") was conducted between 1 January 2005 to 31 March 2018; results from the main clinical trials are discussed. Additional literature known to the authors and identified from the reference lists of cited publications was included. Results: Overall, it should be noted that, in studies which determined pregnancy rates across different weight or BMI categories, the overall pregnancy rate was low (1-2%) and there was no direct evidence that lower levonorgestrel plasma levels contributed to an increased pregnancy rate in obese women. This conclusion was reached by the EMA referral in 2014 and they concluded that emergency contraceptive pills (ECPs) could be taken regardless of body weight or BMI, as soon as possible after UPSI. Since the EMA review, additional evidence has been published regarding this topic. This includes PK data (which can neither support, nor deny the previously submitted meta-analyses during the Article 31 Referral procedure), or re-analyses of the previously submitted data. Conclusions: Evidence published since the EMA referral in 2014 does not change the original conclusions of the agency, which recommended that ECPs could be taken regardless of body weight or BMI, as soon as possible after UPSI.