Comparison of Combined Parenteral and Oral Hormonal Contraceptives: A Systematic Review and Meta-Analysis of Randomized Trials

BACKGROUND

Delivering contraceptive hormones through a transdermal patch or a vaginal ring might have advantages over the traditional oral route.

OBJECTIVES

To compare the effectiveness, compliance, and side effect profile of oral and parenteral drug administration methods.

METHODS

We performed a systematic literature search in four medical databases-MEDLINE (via PubMed), Cochrane Library (CENTRAL), Embase, and Scopus-from inception to 20 November 2022. Randomized controlled trials assessing the efficacy, compliance, and adverse event profile of combined parenteral and oral hormonal contraceptives were included.

RESULTS

Our systematic search provided 3952 records; after duplicate removal, we screened 2707 duplicate-free records. A total of 13 eligible studies were identified after title, abstract, and full-text selection. We observed no significant difference in contraceptive efficacy (Pearl Index) between oral and parenteral drug administration (MD = -0.06, CI: -0.66-0.53; I2 = 0%). We found significant subgroup differences between parenteral methods in terms of compliance (χ2 = 4.32, p =0.038, I2 = 80%) and certain adverse events: breast discomfort (χ2 = 19.04, p =0.001, I2 = 80%), nausea (χ2 = 8.04, p =0.005, I2 = 75%), and vomiting (χ2 = 9.30, p =0.002; I2 = 72%).

CONCLUSION

Both parenteral and oral contraceptives can be used as an effective contraceptive method, and the route of administration should be tailored to patient needs and adverse event occurrence.

The new low-dose transdermal contraceptive system (Twirla®): results from preclinical and Phase III trials

A new low-dose, once-a-week contraceptive transdermal delivery system (TDS) with 2.3-mg ethinyl estradiol (EE) and 2.6-mg levonorgestrel (LNG; Twirla^®) has recently been approved by the US FDA for contraception of women with BMI <30 kg/m². The rationale for developing this new patch, the preclinical study results and the results from two innovative Phase III clinical trials demonstrate that this patch has an acceptable Pearl index (4.3%) for its indicated users and has safety and tolerability comparable to other similar dose oral combined hormonal contraceptives. This new TDS provides an improvement over the existing TDS products, with significantly lower steady-state estrogen exposure, a level equal to that with 30-µg EE containing oral contraceptives.

Transdermal delivery of combined hormonal contraception: a review of the current literature

The transdermal patch provides an effective and convenient option for hormonal contraception. The patch currently on the US market contains 150 µg norelgestromin and 35 µg ethinylestradiol (EE). The 20 cm² patch is applied once weekly for 3 weeks, followed by a patch-free week, for a 21–7 cycle. Typical failure rates are similar to that of combined oral contraceptives (COCs). Transdermal delivery results in less peaks and troughs of estrogen, but a higher total estrogen exposure compared with COCs. Though studies show mixed results, the risk of developing venous thromboembolism (VTE) is about twice as high with the patch as with COCs; however, the absolute risk of VTE remains low. The side effect profile is similar to that of COCs, with slightly higher rates of breast tenderness plus a unique adverse effect of application site reactions. Two new patches have been developed, one containing gestodene and EE in Europe and another containing levonorgestrel and EE. Overall, the patch provides an alternative to COCs for women who want autonomy and the benefit of not needing to take a pill daily, with similar efficacy and tolerability.

Pharmacokinetics and adhesion of a transdermal patch containing ethinyl estradiol and gestodene under conditions of heat, humidity, and exercise: A single-center, open-label, randomized, crossover study

In this open-label, randomized study, 36 women (18-45 years) applied an ethinyl estradiol/gestodene contraceptive patch once-weekly for 3 weeks followed by a 1-week, patch-free interval, in 3 treatment periods. The primary objective was to evaluate the pharmacokinetics of ethinyl estradiol and gestodene under conditions of heat, humidity, and exercise. The secondary objective was to evaluate patch adhesion under the same conditions. Weeks 1 and 2 of each period comprised "standardized normal activity" (SNA); in week 3, SNA continued or women used a sauna, whirlpool, swimming pool, or performed an exercise combination. Thirty-one women completed the study; 23 yielded evaluable pharmacokinetic data. Analyses were exploratory and conducted using an analysis of variance. Area under the concentration-time curve from 0 to 168 hours (AUC0-168 ) for gestodene and ethinyl estradiol during sauna, swimming, and whirlpool was equivalent to previous SNA recordings. For exercise combination, the gestodene AUC0-168 was 12% lower compared with SNA, albeit not considered clinically relevant. Two women lost a total of 3 patches during sporting activities; other detachments during this week were not correlated with sporting activity. Overall, hormone delivery using the ethinyl estradiol/gestodene patch under conditions of heat, humidity, and exercise corresponded to delivery under normal conditions.

Safety and tolerability of a new low-dose contraceptive patch in obese and nonobese women

OBJECTIVE

The safety and tolerability of a new low-dose levonorgestrel/ethinyl estradiol (LNG/EE) contraceptive patch was compared with 2 combination oral contraceptives in 2 clinical studies in which approximately 30% of enrolled participants were obese.

STUDY DESIGN

Two phase 3, open-label, randomized, parallel-group, multicenter trials compared the LNG/EE contraceptive patch (n = 1579) with combination oral contraceptives (n = 581) in healthy women 17-40 years of age. Combination oral contraceptives were LNG 100 μg per EE 20 μg (combination oral contraceptive 20; n = 375) or LNG 150 μg per EE 30 μg (combination oral contraceptive 30; n = 206). Safety and tolerability data from the 2 trials were evaluated in integrated safety analyses.

RESULTS

Treatment-emergent adverse events of 2% or greater in the LNG/EE contraceptive patch were nasopharyngitis (5.2%), nausea (4.1%), upper respiratory infection (3.5%), headache (3.4%), sinusitis (2.9%), cervical dysplasia (2.3%), and urinary tract infection (2.1%). Including skin reaction-related treatment-emergent adverse events, the proportion of women who experienced any treatment-emergent adverse event was similar among women randomized to the contraceptive patch (47.5%), the combination oral contraceptive 20 (47.4%), or the combination oral contraceptive 30 (46.8%). The incidence of treatment-emergent adverse events was similar in obese vs nonobese participants in all groups. Serious adverse events occurred in less than 1% of participants in any of the treatment groups.

CONCLUSION

The LNG/EE contraceptive patch and combination oral contraceptives were well tolerated and associated with similar treatment-emergent adverse event incidences in obese and nonobese women.

Influence of structured counseling on women's selection of hormonal contraception in Israel: results of the CHOICE study

Background

The multinational CHOICE (Contraceptive Health Research Of Informed Choice Experience) study evaluated the effects of structured counseling on women’s contraceptive decisions, their reasons for making those decisions, and their perceptions of combined hormonal contraceptive (CHC) methods in eleven countries. The aim of this paper to present data from the 1,802 women participating in Israel’s CHOICE program.

Methods

Women (aged 17–40 years) who consulted their health care providers about contraception and who would consider a CHC method qualified to participate. After indicating their intended CHC method, the women received counseling about the daily pill, weekly patch, and monthly vaginal ring. After counseling, the women completed a questionnaire about their contraceptive decisions.

Results

Before counseling, 67%, 6%, and 5% of women (mean age 27 years) intended to use the pill, patch, or ring, respectively. Counseling significantly influenced the women’s CHC choice, with 56%, 12%, and 23% of women selecting the pill, patch, or ring (P<0.0001 for all contraceptive methods versus before counseling). Logistic regression analysis suggested that age significantly increased the probability of switching from the pill to the ring.

Conclusion

Although the pill was the most popular choice overall, counseling appeared to influence Israeli women’s contraceptive decisions, with significantly more women selecting the patch. More than four times as many women selected the ring after counseling than before counseling.

With pills, patches, rings, and shots: who still uses condoms? A longitudinal cohort study

PURPOSE

To describe women's condom use patterns over time and assess predictors of dual method use 12 months after initiating hormonal contraceptives.

METHODS

We conducted a prospective cohort study among women aged 15-24 years initiating oral contraceptive pills, patch, ring, or depot medroxyprogesterone and attending public family planning clinics. Participants completed questionnaires at baseline and 3, 6, and 12 months after enrollment. We used multivariable logistic regression to assess baseline factors associated with dual method use at 12 months among 1,194 women who were sexually active in the past 30 days.

RESULTS

At baseline, 36% were condom users, and only 5% were dual method users. After initiation of a hormonal method, condom use decreased to 27% and remained relatively unchanged thereafter. Dual method use increased to a peak of 20% at 3 months but decreased over time. Women who were condom users at baseline had nearly twice the odds of being a dual method user at 12 months compared with nonusers (adjusted odds ratio [AOR] = 2.01, 95% CI: 1.28-3.14). Women who believed their main partner thought condoms were "very important," regardless of perceived sexually transmitted infection risk or participant's own views of condoms, had higher odds of dual method use (AOR = 2.89, 95% CI: 1.47-5.71).

CONCLUSIONS

These results highlight a potential missed opportunity for family planning providers. Providers focus on helping women initiate hormonal methods, however, they may improve outcomes by giving greater attention to method continuation and contingency planning in the event of method discontinuation and to the role of the partner in family planning.