Progestins (Etonogestrel, Levonorgestrel, Norethindrone)

Contraceptives containing synthetic progestinic steroids.106 117 119 120 125 a

Contraception

Prevention of conception in women.117 119 120 125 a

Predominantly used by women who are breastfeeding and in those who do not tolerate estrogens or in whom estrogens are contraindicated.b

Levonorgestrel-releasing intrauterine system (Mirena): Intended for women who have had ≥1 child; are in a stable, mutually monogamous relationship; have no history of pelvic inflammatory disease (PID); and have no history of ectopic pregnancy or any condition that would predispose to ectopic pregnancy.117

Postcoital (Emergency) Contraception

Prevention of conception after unprotected intercourse (including known or suspected contraceptive failure) as an emergency contraceptive (“morning-after” pills). 101 102 106 126 127 128 129 130 132 133 136 137 Postcoital (emergency) contraceptive regimens are not as effective as most other forms of long-term contraception; do not use as routine forms of contraception.106 126 127 132 133 137

An emergency contraceptive regimen employing a progestin alone (levonorgestrel) appears to be more effective and better tolerated than a common estrogen-progestin emergency contraceptive (“Yuzpe”) regimen when the regimens are initiated within 72 hours of unprotected intercourse; levonorgestrel generally preferred when readily available.101 102 126 127 128 129 136

Storage

Oral

Levonorgestrel: 20–25°C.106 132 133 137

Norethindrone: 25°C (may be exposed to 15–30°C).119 120

Implant

Etonogestrel implant (Implanon): 25°C (may be exposed to 15–30°C).125 Protect from light; avoid direct sunlight.125

Intrauterine System

• Progestin contraceptives produce contraceptive effects by suppressing ovulation, thickening cervical mucus (thus inhibiting sperm migration into the uterus), lowering mid-cycle LH and FSH peaks, slowing ovum movement through the fallopian tubes, and/or alteration of the endometrium.117 119 120 125 126 127 a

• Progestin contraceptives administered after intercourse (postcoital) produce contraceptive effects by inhibiting or delaying ovulation or fertilization.106 126 132 Recent evidence suggests that any endometrial effects are insufficient to prevent implantation.126 127 Effects on ovulation alone cannot explain efficacy of postcoital (emergency) contraceptive; interference of sperm transport or penetration and/or impairment of corpus luteum function proposed as contributing factors.126 127 Only effective before pregnancy is established; not effective after implantation of a fertilized ovum.106 126 127 128 132

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

FDA has approved Next Choice One Dose for OTC status for women ≥17 years of age;137 the contraceptive remains a prescription-only preparation for women <17 years of age.132

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name