Brand names: Preven
The Preven Emergency Contraception Kit provides "morning after" birth control following a contraceptive failure (for instance, a broken condom) or unprotected intercourse.
The hormone pills in the Preven kit can prevent a pregnancy, but will not end one that's already begun. They work primarily by inhibiting ovulation (release of an egg) and possibly by blocking fertilization and implantation of the egg in the lining of the uterus.
Preven is meant for emergency use only and not as a regular method of birth control. When taken within 72 hours after unprotected intercourse, the pills in the Preven kit reduce the chance of pregnancy by 75 percent. In contrast, regular use of oral contraceptives slashes the odds of a pregnancy to 0.5 percent or less.
Before you take the pills, you must first take the pregnancy test provided in the kit. You should take the pills only if the test indicates that you are not pregnant.
Take the first dose as soon as possible after intercourse, within 72 hours at the latest. The second dose must be taken exactly 12 hours after the first. Do not take any extra pills. They won't improve your odds of avoiding pregnancy, but they will increase the likelihood of side effects such as nausea and vomiting.
About half of the women who use Preven experience temporary nausea, and one woman in five actually vomits. One woman in four suffers temporary menstrual irregularities; 10 to 20 percent develop breast tenderness, and 10 percent have headaches. Less common complaints include abdominal pain and dizziness. Side effects usually disappear within a day or two after taking the pills.
The pills in the Preven kit are combination oral contraceptive tablets. Regular use of such pills is not recommended for women with the following conditions:Blood clots in the deep veins of the legsBlood clot in the lungsDiabetes with blood vessel problemsHeart attackHeart diseaseLiver tumors or liver diseasePregnancySevere headaches such as migrainesSevere high blood pressureA history of strokeHeavy smoking (more than 15 cigarettes a day) past age 35An allergy to the pills
If you meet any of these criteria, consult with your doctor about the advisability of using Preven.
You may notice temporary changes in your menstrual cycle after you use Preven. If your period lasts longer than normal, or fails to start within 21 days after taking the pills, call your doctor. In any event, a follow-up visit with your doctor is recommended after 3 weeks.
If you miss your period after using Preven, do call your doctor as soon as possible, but don't be alarmed. Women who unknowingly take combination oral contraceptives while pregnant do not face any increased risk of harm to the baby.
Preven may not prevent an ectopic pregnancy (pregnancy outside of the womb). This type of pregnancy is a medical emergency. Warning signs include spotting and cramping pain shortly after the first menstrual period following use of Preven. Call your doctor immediately if these symptoms appear.
Although it's not known whether occasional use of Preven has the same effect, regular use of combination oral contraceptives poses a slight risk of blood clots and liver problems. If you develop any of the following warning signs while using (or shortly after using) Preven, call your doctor immediately:
Emergency contraception pills, like all oral contraceptives, do not protect against infection with HIV, the virus that causes AIDS, or other sexually transmitted diseases.Possible food and drug interactions when taking Levonorgestrel and Ethinyl Estradiol
If Preven is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Preven with the following:AlcoholAmitriptylineAmpicillinCisaprideCyclosporineGriseofulvinImipramineMetoclopramideRifampinSeizure medications such as barbituratesTetracyclineTheophyllineVitamin C supplements
If taken by mistake during early pregnancy, Preven is unlikely to cause any harm to the developing baby. The hormones in Preven do appear in breast milk, but do not seem to cause any harm to a nursing infant.
There are 4 pills in the Preven Emergency Contraception Kit. The first dose of 2 pills must be taken within 72 hours of unprotected intercourse. The second dose of 2 pills must be taken 12 hours later. If you vomit within 1 hour of taking either dose, check your doctor for further instructions.
An overdose of oral contraceptives poses no danger, though it may cause nausea and vomiting, and, in females, vaginal bleeding. If you suspect an overdose, seek medical attention immediately.