"The U.S. Food and Drug Administration today announced that it has approved an amended application submitted by Teva Women's Health, Inc. to market Plan B One-Step (active ingredient levonorgestrel) for use without a prescription by women 15 years"...
Clinical Trial Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.
A double-blind, controlled clinical trial in 1,955 evaluable women compared the efficacy and safety of Plan B (one 0.75 mg tablet of levonorgestrel taken within 72 hours of unprotected intercourse, and one tablet taken 12 hours later) to the Yuzpe regimen (two tablets each containing 0.25 mg levonorgestrel and 0.05 mg ethinyl estradiol, taken within 72 hours of intercourse, and two tablets taken 12 hours later).
The most common adverse events ( > 10%) in the clinical trial for women receiving Plan B included menstrual changes (26%), nausea (23%), abdominal pain (18%), fatigue (17%), headache (17%), dizziness (11%), and breast tenderness (11%). Table 1 lists those adverse events that were reported in ≥ 5% of Plan B users.
Table 1: Adverse Events in ≥ 5%of Women, by % Frequency
|Plan B Levonorgestrel
|Heavier Menstrual Bleeding||13.8|
|Lighter Menstrual Bleeding||12.5|
The following adverse reactions have been identified during post-approval use of Plan B. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
Abdominal Pain, Nausea, Vomiting
General Disorders and Administration Site Conditions
Nervous System Disorders
Reproductive System and Breast Disorders
Read the Plan B (levonorgestrel) Side Effects Center for a complete guide to possible side effects
Drugs or herbal products that induce enzymes, including CYP3A4, that metabolize progestins maydecrease the plasma concentrations of progestins, and may decrease the effectiveness of progestin-only pills. Some drugs or herbal products that may decrease the effectiveness of progestin-only pills include:
- St. John's wort
Significant changes (increase or decrease) in the plasma levels of the progestin have been noted in some cases of co-administration with HIV protease inhibitors or with non-nucleoside reverse transcriptase inhibitors.
Consult the labeling of all concurrently used drugs to obtain further information about interactions with progestin-only pills or the potential for enzyme alterations.
Drug Abuse And Dependence
Levonorgestrel is not a controlled substance. There is no information about dependence associated with the use of Plan B.
Read the Plan B Drug Interactions Center for a complete guide to possible interactions
Last reviewed on RxList: 9/22/2016
Additional Plan B Information
Plan B - User Reviews
Plan B User Reviews
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Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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