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Levonorgestrel (Systemic)

Pronunciation

Pronunciation

(LEE voe nor jes trel)

Index Terms

  • LNg 20
  • Plan B

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Tablet, Oral:

Aftera: 1.5 mg

EContra EZ: 1.5 mg

Fallback Solo: 1.5 mg

My Way: 1.5 mg

Next Choice: 0.75 mg [DSC] [contains fd&c yellow #6 (sunset yellow)]

Next Choice One Dose: 1.5 mg [contains fd&c yellow #6 (sunset yellow)]

Opcicon One-Step: 1.5 mg

Plan B: 0.75 mg [DSC]

Plan B One-Step: 1.5 mg

React: 1.5 mg [contains corn starch]

Take Action: 1.5 mg

Generic: 0.75 mg [DSC], 1.5 mg

Brand Names: U.S.

  • Aftera [OTC]
  • EContra EZ [OTC]
  • Fallback Solo [OTC]
  • My Way [DSC]
  • My Way [OTC]
  • Next Choice One Dose [DSC]
  • Next Choice One Dose [OTC]
  • Next Choice [DSC]
  • Opcicon One-Step [OTC]
  • Plan B One-Step [DSC]
  • Plan B One-Step [OTC]
  • Plan B [DSC]
  • React [OTC]
  • Take Action [OTC]

Pharmacologic Category

  • Contraceptive
  • Progestin

Pharmacology

Pregnancy may be prevented through several mechanisms: Thickening of cervical mucus, which inhibits sperm passage through the uterus and sperm survival; inhibition of ovulation, from a negative feedback mechanism on the hypothalamus, leading to reduced secretion of follicle stimulating hormone (FSH) and luteinizing hormone (LH); altering the endometrium, which may affect implantation. Levonorgestrel is not effective once the implantation process has begun.

Absorption

Oral: Rapid and complete

Distribution

Vd: ~1.8 L/kg

Metabolism

Hepatic via CYP3A4; forms inactive metabolites

Excretion

Urine (45%); feces (32%)

Time to Peak

Oral: ~2 hours

Half-Life Elimination

Oral: ~27 hours

Protein Binding

Highly bound to albumin (~50%) and sex hormone-binding globulin (~47%) (Fotherby, 1995)

Special Populations: Race

There was a higher increase in the rate of pregnancy in Chinese women using Next Choice or Plan B One-Step; the reason for this apparent increase is unknown.

Use: Labeled Indications

Emergency contraception: Emergency contraception following unprotected intercourse or possible contraceptive failure

Contraindications

Known or suspected pregnancy

It is not known if the same contraindications associated with long-term progestin-only contraceptives apply to the levonorgestrel emergency contraception dose regimens. A history of ectopic pregnancy is not a contraindication to use in emergency contraception.

OTC labeling: When used for self-medication, do not use if you are already pregnant; do not use for regular birth control

Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to levonorgestrel or any component of the formulation; undiagnosed vaginal bleeding

Dosing: Adult

Emergency contraception: Females: Oral: May be used at any time during menstrual cycle:

Two-dose regimen: One 0.75 mg tablet as soon as possible within 72 hours of unprotected sexual intercourse; a second 0.75 mg tablet should be taken 12 hours after the first dose.

Single-dose regimen: One 1.5 mg tablet as soon as possible within 72 hours of unprotected sexual intercourse.

Note: Treatment for emergency contraception should begin as soon as possible; however, treatment is still moderately effective if used within 5 days and should be made available to women up to 5 days after unprotected or inadequately protected intercourse. When using the two-dose emergency contraceptive regimen, the second dose is equally effective if taken 12 to 24 hours after the first (ACOG, 2015).

Dosing: Geriatric

Not indicated for use in postmenopausal women.

Dosing: Pediatric

Emergency contraception: Females: Refer to adult dosing. Not for use prior to menarche.

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied).

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied).

Administration

Oral: Consider repeating the dose if vomiting occurs within 2 hours. Hazardous agent; use appropriate precautions for handling and disposal (NIOSH 2014 [group 2]).

Storage

Store at 20°C to 25°C (68°F to 77°F).

Drug Interactions

Acitretin: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Given the potential for progestin-only preparations to fail to prevent pregnancy during acitretin therapy, such products should not be relied upon. Alternative, nonhormonal forms of contraception must be employed during acitretin therapy. Consider therapy modification

Anticoagulants: Progestins may diminish the therapeutic effect of Anticoagulants. More specifically, the potential prothrombotic effects of some progestins and progestin-estrogen combinations may counteract anticoagulant effects. Management: Carefully weigh the prospective benefits of progestins against the potential increased risk of procoagulant effects and thromboembolism. Use is considered contraindicated under some circumstances. Refer to related guidelines for specific recommendations. Consider therapy modification

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Monitor therapy

Aprepitant: May decrease the serum concentration of Contraceptives (Progestins). Management: Alternative or additional methods of contraception should be used both during treatment with aprepitant or fosaprepitant and for at least one month following the last aprepitant/fosaprepitant dose. Consider therapy modification

Artemether: May decrease the serum concentration of Contraceptives (Progestins). Management: Consider the use of an alternative (i.e., non-hormonal) means of contraception in all women of childbearing potential who are using artemether. Consider therapy modification

Atazanavir: May increase the serum concentration of Contraceptives (Progestins). However, atazanavir may lead to decreased ethinyl estradiol concentrations and decreased effectiveness of oral contraceptive products. Management: Consider an alternative or additional method of contraception, particularly with combined estrogen/progestin products. Depot medroxyprogesterone acetate may be used without a need for additional contraception. Consider therapy modification

Barbiturates: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Use of alternative, nonhormonal contraceptives is recommended. Consider therapy modification

Bexarotene (Systemic): May decrease the serum concentration of Contraceptives (Progestins). Management: Women of childbearing potential receiving bexarotene should use two reliable forms of contraception (including at least one nonhormonal form). Consider therapy modification

Bile Acid Sequestrants: May decrease the serum concentration of Contraceptives (Progestins). Management: Administer oral progestin-containing contraceptives at least 1-4 hours prior to or 4-6 hours after administration of a bile acid sequestrant. Consider therapy modification

Boceprevir: May increase the serum concentration of Contraceptives (Progestins). This has been seen specifically with norethindrone. Boceprevir may increase the serum concentration of Contraceptives (Progestins). This has been seen specifically with drospirenone. Management: Patients receiving boceprevir, ribavirin, and peginterferon alfa should use two reliable forms of contraception. Norethindrone/ethinyl estradiol may be used for one of these when norethindrone dose is at least 1 mg/day. Avoid drospirenone. Consider therapy modification

Bosentan: May decrease the serum concentration of Contraceptives (Progestins). Management: Use an alternative (i.e., non-hormonal) means of contraception for all women of childbearing potential who are using bosentan, and do not rely on hormonal contraceptives alone. Consider therapy modification

C1 inhibitors: Progestins may enhance the thrombogenic effect of C1 inhibitors. Monitor therapy

CarBAMazepine: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Use of alternative, nonhormonal contraceptives is recommended. Consider therapy modification

Carfilzomib: May enhance the thrombogenic effect of Contraceptives (Progestins). Management: Consider alternative, non-hormonal methods of contraception in patients requiring therapy with carfilzomib. Consider therapy modification

CloBAZam: May decrease the serum concentration of Contraceptives (Progestins). Consider therapy modification

Cobicistat: May increase the serum concentration of Contraceptives (Progestins). Management: Consider an alternative, non-hormone-based contraceptive in patients receiving cobicistat-containing products. Consider therapy modification

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates. Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dabrafenib: May decrease the serum concentration of Contraceptives (Progestins). Management: Females of reproductive potential should use an alternative, highly effective, non-hormonal means of contraception during and at least 2 weeks (dabrafenib alone) or 4 months (dabrafenib + trametinib) after discontinuation of dabrafenib treatment. Consider therapy modification

Darunavir: May decrease the serum concentration of Contraceptives (Progestins). Management: Consider using an alternative or additional means of contraception. Injected depot medroxyprogesterone acetate may be used without a need for additional contraception. Consider therapy modification

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Efavirenz: May decrease the serum concentration of Contraceptives (Progestins). Management: Use an alternative or additional method of contraception due to possibly decreased contraceptive effectiveness. Injected depot medroxyprogesterone acetate does not appear to participate in this interaction. Consider therapy modification

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates. Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification

Eslicarbazepine: May decrease the serum concentration of Contraceptives (Progestins). Management: Alternative, non-hormonal means of birth control should be considered for women of child-bearing potential. Consider therapy modification

Exenatide: May decrease the serum concentration of Oral Contraceptive (Progestins). Management: Administer oral contraceptives at least one hour prior to exenatide. Consider therapy modification

Felbamate: May decrease the serum concentration of Contraceptives (Progestins). Management: Contraceptive failure is possible. Use of an alternative, nonhormonal method of contraception is recommended. Consider therapy modification

Flibanserin: Contraceptives (Progestins) may increase the serum concentration of Flibanserin. Monitor therapy

Fosamprenavir: Contraceptives (Progestins) may decrease serum concentrations of the active metabolite(s) of Fosamprenavir. Fosamprenavir may decrease the serum concentration of Contraceptives (Progestins). Management: Consider using an alternative or additional means of contraception. Injected depot medroxyprogesterone acetate may be used without a need for additional contraception. Consider therapy modification

Fosaprepitant: May decrease the serum concentration of Contraceptives (Progestins). The active metabolite aprepitant is likely responsible for this effect. Management: Alternative or additional methods of contraception should be used both during treatment with aprepitant or fosaprepitant and for at least one month following the last aprepitant/fosaprepitant dose. Consider therapy modification

Fosphenytoin: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Contraceptive failure is possible. Use of an alternative, nonhormonal contraceptive is recommended. Consider therapy modification

Griseofulvin: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Avoid combination

Herbs (Progestogenic Properties) (eg, Bloodroot, Yucca): May enhance the adverse/toxic effect of Progestins. Monitor therapy

LamoTRIgine: May decrease the serum concentration of Contraceptives (Progestins). Management: Women using progestin-only “minipill” products may be at risk for contraceptive failure; it is unclear if other progestin-containing products would be significantly impacted. Alternative, non-hormonal, means of contraception are recommended. Consider therapy modification

Lesinurad: May decrease the serum concentration of Contraceptives (Progestins). Management: Use of an additional, nonhormonal contraceptive is recommended in patients being treated with lesinurad who desire effective contraception. Consider therapy modification

Lixisenatide: May decrease the serum concentration of Contraceptives (Progestins). Management: Administer oral contraceptives 1 hour before or at least 11 hours after administration of lixisenatide. Consider therapy modification

Lopinavir: May decrease the serum concentration of Contraceptives (Progestins). Lopinavir may increase the serum concentration of Contraceptives (Progestins). Management: Consider using an alternative or additional means of contraception. Injected depot medroxyprogesterone acetate and etonogestrel implants may be used without a need for additional contraception. Consider therapy modification

Lumacaftor: May decrease the serum concentration of Contraceptives (Progestins). Management: Do not rely on hormone-based contraceptives with concurrent use of lumacaftor/ivacaftor; an alternative, non-hormonal, method of contraception should be used if this combination is required. Consider therapy modification

Metreleptin: May decrease the serum concentration of Contraceptives (Progestins). Metreleptin may increase the serum concentration of Contraceptives (Progestins). Monitor therapy

MiFEPRIStone: May diminish the therapeutic effect of Contraceptives (Progestins). MiFEPRIStone may increase the serum concentration of Contraceptives (Progestins). Management: Women of childbearing potential should use an effective, nonhormonal means of contraception during and 4 weeks following mifepristone treatment. Consider therapy modification

Mitotane: May decrease the serum concentration of CYP3A4 Substrates. Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification

Mycophenolate: May decrease the serum concentration of Contraceptives (Progestins). Management: Use of an additional or alternative (nonhormonal) method of contraception should be considered. Consider therapy modification

Nelfinavir: May decrease the serum concentration of Contraceptives (Progestins). Management: Use an alternative or additional method of contraception due to possibly decreased contraceptive effectiveness. Injected depot medroxyprogesterone acetate does not appear to participate in this interaction. Consider therapy modification

Nevirapine: May decrease the serum concentration of Contraceptives (Progestins). Management: Instruct patients receiving nevirapine to use an alternative or additional nonhormonal contraceptive. Nevirapine product labeling however suggests that depo-medroxyprogesterone acetate may be used as a sole method of contraception. Consider therapy modification

OXcarbazepine: May decrease the serum concentration of Contraceptives (Progestins). Management: Contraceptive failure is possible. Use of an additional or alternative, nonhormonal method of contraception is recommended. Consider therapy modification

Perampanel: May decrease the serum concentration of Contraceptives (Progestins). Management: Patients should use an alternative, non-hormonal based form of contraception for the duration of concurrent perampanel. Both oral and non-oral progestin-based contraceptives are likely to be impacted by this interaction. Consider therapy modification

Phenytoin: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Contraceptive failure is possible. Use of an alternative, nonhormonal contraceptive is recommended. Consider therapy modification

Pomalidomide: Progestins may enhance the thrombogenic effect of Pomalidomide. Management: Canadian pomalidomide labeling recommends caution with use of hormone replacement therapy and states that hormonal contraceptives are not recommended. US pomalidomide labeling does not contain these specific recommendations. Consider therapy modification

Primidone: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Use of alternative, nonhormonal contraceptives is recommended. Consider therapy modification

Prucalopride: May decrease the serum concentration of Contraceptives (Progestins). Consider therapy modification

Retinoic Acid Derivatives: May diminish the therapeutic effect of Contraceptives (Progestins). Retinoic Acid Derivatives may decrease the serum concentration of Contraceptives (Progestins). Management: Two forms of effective contraception should be used in patients receiving retinoic acid derivatives. Particularly, microdosed progesterone-only preparations may be inadequately effective. Exceptions: Adapalene; Bexarotene (Topical); Tretinoin (Topical). Consider therapy modification

Rifamycin Derivatives: May decrease the serum concentration of Contraceptives (Progestins). Contraceptive failure is possible. Management: Contraceptive failure is possible. Use of an alternative, nonhormonal contraceptive is recommended. Consider therapy modification

Saquinavir: May decrease the serum concentration of Contraceptives (Progestins). Management: Use an alternative or additional method of contraception due to possibly decreased contraceptive effectiveness. Injected depot medroxyprogesterone acetate does not appear to participate in this interaction. Consider therapy modification

Selegiline: Contraceptives (Progestins) may increase the serum concentration of Selegiline. Monitor therapy

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

St John's Wort: May diminish the therapeutic effect of Contraceptives (Progestins). Contraceptive failure is possible. Management: Consider using a product other than St John's wort. Contraceptive failure is possible. Use of an alternative, nonhormonal contraceptive is recommended. Consider therapy modification

St John's Wort: May decrease the serum concentration of CYP3A4 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

Sugammadex: May decrease the serum concentration of Contraceptives (Progestins). Management: Patients receiving any hormonal contraceptive (oral or non-oral) should use an additional, nonhormonal contraceptive method during and for 7 days following sugammadex treatment. Consider therapy modification

Telaprevir: May decrease the serum concentration of Contraceptives (Progestins). Management: Two different nonhormonal forms of contraception are required for women of childbearing potential taking telaprevir. Hormonal contraceptives may be less effective during concurrent telaprevir and for up to 2 weeks after telaprevir discontinuation. Consider therapy modification

Thalidomide: Contraceptives (Progestins) may enhance the thrombogenic effect of Thalidomide. Monitor therapy

Tipranavir: May increase the serum concentration of Contraceptives (Progestins). Management: Use an alternative or additional method of contraception due to possibly decreased contraceptive effectiveness. Injected depot medroxyprogesterone acetate does not appear to participate in this interaction. Consider therapy modification

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates. Monitor therapy

Topiramate: May decrease the serum concentration of Contraceptives (Progestins). Management: Caution patients that this combination may be associated with reduced contraceptive effectiveness. Consider adding an additional (non-hormonal) contraceptive method. Consider therapy modification

Tranexamic Acid: Contraceptives (Progestins) may enhance the thrombogenic effect of Tranexamic Acid. Avoid combination

Ulipristal: May diminish the therapeutic effect of Progestins. Progestins may diminish the therapeutic effect of Ulipristal. Management: Ulipristal for uterine fibroids (Canadian indication): avoid progestins within 12 days of stopping ulipristal; as emergency contraceptive (U.S. indication): avoid progestins within 5 days of stopping ulipristal. Avoid combination

Vitamin K Antagonists (eg, warfarin): Contraceptives (Progestins) may diminish the anticoagulant effect of Vitamin K Antagonists. In contrast, enhanced anticoagulant effects have also been noted with some products. Management: When possible, concomitant hormonal contraceptives and coumarin derivatives should be avoided in order to eliminate the risk of thromboembolic disorders. Consider using an alternative, nonhormonal contraceptive. Consider therapy modification

Voriconazole: May increase the serum concentration of Contraceptives (Progestins). Contraceptives (Progestins) may increase the serum concentration of Voriconazole. Monitor therapy

Adverse Reactions

Frequency not always defined.

>10%:

Central nervous system: Fatigue (13%)

Endocrine & metabolic: Hypermenorrhea (31%)

Gastrointestinal: Nausea (14%), abdominal pain (13%)

1% to 10%:

Central nervous system: Dizziness (10%), headache (10%)

Endocrine & metabolic: Suppressed menstruation (5%)

Genitourinary: Breast tenderness (8%)

Postmarketing and/or case reports: Dysmenorrhea

Warnings/Precautions

Concerns related to adverse effects:

• Bleeding irregularities: Spotting may occur following use; the possibility of pregnancy should be considered if menstruation is delayed for >7 days of the expected menstrual period.

• Ectopic pregnancy: A history of ectopic pregnancy is not a contraindication for use as an emergency contraceptive. The possibility of ectopic pregnancy should be considered in patients with lower abdominal pain, especially in association with missed periods or vaginal bleeding in women with prior amenorrhea. Ectopic pregnancy may result in loss of fertility.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Pediatric: Not for use prior to menarche.

• Postmenopausal women: Not indicated for use in postmenopausal women.

Special handling:

• Hazardous agent: Use appropriate precautions for handling and disposal (NIOSH 2014 [group 2]).

Other warnings/precautions:

• Appropriate use: Not intended to be used for routine contraception and is not effective in terminating an existing pregnancy.

• Body weight: When used for emergency contraception, reduced efficacy has been reported in women ≥75 kg to 80 kg and lack of efficacy has been reported in women >80 kg; the Canadian labeling recommends that alternative emergency contraceptive methods be considered (Plan B Canadian product monograph 2014). The CDC recommends that obese women can generally use any type of contraceptive but suggests that levonorgestrel may be less efficacious in obese women compared to ulipristal acetate (CDC, 2013).

• Fertility: Barrier contraception is recommended immediately following emergency contraception (ACOG, 2015; CDC, 2013).

• HIV infection protection: Hormonal contraceptives do not protect against HIV infection or other sexually-transmitted diseases (CDC, 2013).

Monitoring Parameters

Evaluate for pregnancy, spontaneous abortion or ectopic pregnancy if menses is delayed for ≥1 week following emergency contraception, or if lower abdominal pain or persistent irregular bleeding develops.

Pregnancy Considerations

Use during pregnancy is contraindicated. When pregnancies have continued following levonorgestrel exposure, congenital anomalies have been infrequent. Significant adverse effects on infant growth and development have not been observed (limited data).

Levonorgestrel may be used as an emergency contraceptive in women with contraindications to conventional oral contraceptive agents (eg, cardiovascular disease, migraines, liver disease) (CDC 2010). A rapid return of fertility is expected following use for emergency contraception; routine contraceptive measures should be initiated or continued following use to ensure ongoing prevention of pregnancy. Any regular contraceptive method can be started immediately after levonorgestrel; however, a barrier method (or abstinence from sexual intercourse) is also needed for 7 days (ACOG 2015; CDC 2013).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience headache, nausea, breast soreness, dizziness, menstrual changes, or loss of strength and energy. Have patient report immediately to prescriber severe abdominal pain (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

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