Pharmacy Times Interactive Case Studies: March 2023 Issue

Case 1:

TS is a 32-year-old woman whose birth control prescription is for ethinyl estradiol 20 mcg/norethindrone acetate 1 mg to be taken once daily for 21 days, followed by 7 days of nonhormonal placebo pills. The pharmacist notices that she brings in a prescription for ethinyl estradiol 30 mcg/levonorgestrel 120 mcg transdermal patch. Upon talking with TS, the pharmacist learns that she had trouble remembering to take her birth control pills because of her erratic work schedule. Collaboratively, TS and her obstetrician-gynecologist decided to switch her to the transdermal patch to improve adherence and reduce the risk of unintended pregnancy. As the pharmacist fills the prescription, TS asks when she should start the patch, because she has 10 pills left in her pack (3 active and 7 placebo pills).

How should the pharmacist respond?

The pharmacist should explain that TS should finish her pill cycle and apply the patch on the day the next pill cycle would normally start (ie, in 11 days).¹ If her period does not start within a week after taking the last active pill, she should contact her ob-gyn for further instructions. This is to ensure that TS is not pregnant before starting a new contraceptive method. If she has trouble remembering to take her pills, encourage her to carry her pills with her and set an alarm alerting her to take the pills at the same time each day. While she is transitioning to a new birth control method that will hopefully be easier to use, minimizing the risk of unintended pregnancy during the transition periodis critical.

Case 2:

Three months later, TS calls the pharmacist seeking new advice. She reminds the pharmacist that she started using ethinyl estradiol 30 mcg/levonorgestrel 120 mcg transdermal patch for birth control about 3 months ago. TS was instructed to apply the patch once weekly to her upper torso for 3 weeks; the fourth week is patch free. She says she applies her patch on Mondays and confirms she applied it this past Monday. But now it is Thursday, and TS notices that her patch has fallen off and cannot confirm when it detached. She asks what to do and wonders whether she needs to purchase emergency contraceptive.

What should the pharmacist tell TS?

Because TS cannot verify when the patch fell off, she may not be fully protected from pregnancy. The pharmacist should advise her to stop her patch cycle and start over on a new cycle right away by putting on a new patch.¹ Thursday is now day 1 of TS’s new cycle and becomes her new patch change day. The pharmacist should also encourage TS to avoid sexual intercourse or use backup contraception, such as a diaphragm, condom, or spermicide, until she has worn a new patch for 7 consecutive days. Emergency contraception may be considered if TS had unprotected sexual intercourse in the previous 5 days.²

References

1. Twirla. Prescribing information. Agile Therapeutics, Inc; 2022. Accessed February 8, 2023. https://www.twirla.com/pdf/Twirla%20FINAL%20USPI%20PPI%20IFU.pdf#page=25

2. Curtis KM, Jataoui TC, Tepper NK, et al. U.S. selected practice recommen-dations for contraceptive use, 2016. MMWR Reconn Rep. 2016;65(4):1-66. doi:10.15585/mmwr.rr6504a

About the Author

Stefanie C. Nigro, PharmD, BCACP, CECES, is an associate clinical professor in the Department of Pharmacy Practice at the University of Connecticut School of Pharmacy in Storrs.