Chapter 14: Hormonal and Emergency Contraception

LEARNING OBJECTIVES

1. Compare and contrast the various methods of hormonal contraception and emergency contraception.

2. Describe the indications and contraindications in the selection of optimal and safe contraceptives for a specific patient.

3. Identify and manage potential drug interactions and adverse effects with hormonal contraceptives, and design a plan to manage them appropriately.

4. Discuss the mechanisms of action by which contraceptives work.

5. Describe the role of pharmacists in the provision of contraception and follow-up services for women/men requesting it.

INTRODUCTION

The introduction of the first combined oral contraceptive (COC) in 1960 marked the beginning of a transition into improved female reproductive health, sex equity, quality of life for women, a sense of freedom for sexually active women, and changes in demographics regarding unplanned pregnancies. Over the last 60 years, advances in contraception have improved effectiveness and minimized side effects. Hormonal contraception for women is now available in many dosage forms including intrauterine devices (IUDs), implant, transdermal patch, vaginal ring, injectables, and oral tablets, which provide more options to suit individual’s needs and preferences.¹

In this chapter, terms such as emergency contraception (EC), ongoing hormonal contraception, and, simply, hormonal contraception will be used. Apart from the copper IUD, a nonhormonal form of EC, EC is a term used in this chapter to refer to a postcoital form of hormonal contraception. The term ongoing contraception in this chapter refers to hormonal contraception used over a period of time prior to coitus to provide contraceptive coverage. The term hormonal contraception can refer in this chapter to both EC and ongoing hormonal contraception.

Access to and proper use of contraception has socioeconomic implications. In 2011, 45% of all reported pregnancies were unintended.² In that same year, the proportion of unintended pregnancies that resulted in abortions was 42%.² The Centers for Disease Control and Prevention (CDC) reports that in 2015, the birth rate of children born to women 15 to 19 years old reached a historic low, falling 46% since 2007 and 64% since 1991.³ However, teen birth rates in 2015 in the United States were among the highest compared to other industrialized nations, and pregnancy rates were disproportionately higher in Black and Hispanic teens.³ Women who have unintended pregnancies are less likely to continue their education and are three times as likely to become victims of interpersonal violence.^4,5

Proper use of contraception is critical, as contraception failure rates increase with human error. From 2011 to 2013, 61.7% of women in the United States used some form of contraception with 27.6% using long-acting reversible contraception (LARC) or ongoing hormonal contraception.^1,6 Use of these contraceptives with typical use results in the following rates of unintended pregnancies in the first year of use: condoms (18% male condoms, 21% female condoms); diaphragm (12%); oral contraceptives, contraceptive patch, and contraceptive ring (9%); progestin injection (6%); ...