Hormonal Emergency Contraception

Melissa Sanders Wanner, Pharm.D., Rachel L. Couchenour, Pharm.D.


Pharmacotherapy. 2002;22(1) 

In This Article

Adverse Effects and Contraindications

Nausea and vomiting are the most common adverse effects after treatment with the Yuzpe regimen, occurring at frequencies of 30-50% and 15-25%, respectively.[4] Other common adverse effects include fatigue, breast tenderness, headache, abdominal pain, and dizziness.[4]

Some clinicians routinely give antiemetics 1 hour before administration of the Yuzpe regimen (Table 3).[28] To our knowledge, only one study has been performed to examine the effectiveness of antiemetics in reducing the nausea and vomiting associated with emergency contra-ceptives.[29] In this study, a total of 343 women who were not at risk of becoming pregnant were randomly assigned to receive pretreatment with meclizine 50 mg, placebo, or no drug 1 hour before the first dose of the Yuzpe regimen. Women who received meclizine experienced significantly less nausea compared with the other two groups (47% vs 64%, respectively). Severity of nausea and the frequency of vomiting were also significantly lower in the meclizine group. Almost twice as many women experienced drowsiness in the meclizine group (31%) compared with the placebo (13%) and no pretreatment (16%) groups.[29]

Levonorgestrel alone is better tolerated than the Yuzpe regimen. In a study that compared the two regimens, levonorgestrel caused significantly less nausea, vomiting, dizziness, and fatigue (p<0.01).[10]

According the American College of Obstetricians and Gynecologists and the World Health Organization, there are no absolute medical contraindications to the use of emergency contraception with the exception of pregnancy.[30,31] The daily dose of steroidal hormone(s) provided in these products is high; however, they are taken for only a short time, thus the contraindications cited for cyclical combination oral contraceptive pills are not thought to apply. There is no evidence of increased risk or confirmed safety in women who have contraindications to daily use of oral contraceptives. The package insert with the Preven emergency contraceptive kit provides little guidance in the area of contraindications. It lists the known contraindications of daily combination oral contraceptive pills but states that it is not known whether these contraindications apply to Preven.[26] The Plan B package insert does not recommend the product for use in women known or suspected to be pregnant, in those with hypersensitivity to any component of the product, or when undiagnosed abnormal genital bleeding is present.[27]


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: