As a form of progesterone, Preven exerts its actions on the hypothalamus through a negative feedback mechanism, which causes a decrease in the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Both LH and FSH normally stimulate ovulation. Thus, by reducing their secretion, Preven serves to inhibit ovulation. The drug also inhibits implantation, the point when a fertilized egg embeds in the uterine wall, where it will grow and develop into an embryo. In addition, Preven causes the mucus in the cervix to thicken, which blocks the ability of sperm to travel through the uterus and into the fallopian tubes, where fertilization of the egg by a sperm normally takes place.
In the early 1980s Preven became w > Norplant. In this system Preven was implanted beneath the skin of the upper arm in six Silastic (silicone-plastic) capsules, which prov > Norplant II (Jadelle), which uses a different synthetic progestogen, called etonogestrel, implanted under the skin in specially designed rods the size of matchsticks.
What brand names are available for Preven-oral?
Plan B One-Step, Next Choice One Dose, My Way
Intrauterine system (Mirena): 52 mg Preven
Tablets (Plan B): 1.5 mg
Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.
Apply the skin patch to clean, dry skin on your lower stomach. The patch should be worn around-the-clock for one week. Choose a different place on your lower stomach each time you apply a new patch. Avoid skin that is oily, irritated, or damaged.
Change your patch on the same day each week to stay on schedule.
Do not apply a skin patch to your breasts. Do not apply a patch where it might be rubbed off by tight clothing, such as under an elastic waistband.
If a patch falls off, try putting it back on to a different skin area, pressing the patch into place for 10 seconds. If the patch will not stick you may apply a new one.
If you need major surgery or will be on long-term bed rest, you may need to stop using this medicine for a short time. Any doctor or surgeon who treats you should know that you are using estradiol and Preven.
Your doctor should check your progress on a regular basis to determine whether you should continue this treatment. Self-examine your breasts for lumps on a monthly basis, and have regular mammograms while using estradiol and Preven.
Store patches at room temperature away from moisture and heat. Keep each patch in its pouch until you are ready to use it.
After removing a skin patch, fold it in half so it sticks together. Discard the folded patch in a place children and pets cannot get to.
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Apply a skin patch as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not apply two doses at one time.
Copyright 1996-2019 Cerner Multum, Inc.
Latest Update: 11/9/2018, Version: 4.03
Preven is a form of contraceptive used to prevent pregnancy after unprotected sex. Should not be used by women who are >35 yrs of age and smoke.
Preven Food Interactions
Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Preven, there are no specific foods that you must exclude from your diet when receiving this medication.
How is this medicine (Preven) best taken?
Use Preven (systemic) as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take Preven (systemic) within 72 hours after unprotected sex. Take it as soon as you can.
- If you throw up within 2 hours of taking Preven (systemic), you may need to take 1 more dose. Call your doctor right away.
What do I do if I miss a dose?
- Call your doctor to find out what to do.
- Do not take 2 doses at the same time or extra doses.
Preven is well-absorbed from the gastrointestinal tract and is extensively bound to plasma proteins (97 to 99%), including albumin and sex hormone binding globulin Kuhnz et al. (1995) . It is not subject to first-pass hepatic metabolism and is around 100% bioavailable Goldzieher (1989) . About 45% of Preven and its metabolites are excreted in the urine and about 32% are excreted in feces, mostly as glucuronide conjugates (DrugBank). The pharmacokinetics of Preven may be altered in obesity, where the half-life and time to steady state may be prolonged; this may have implications for the effectiveness of contraceptives based on Preven in obese women, although the available evidence suggests that this is only clinically important in emergency hormonal contraception using Preven Simmons and Edelman (2016) .
How should I take Preven emergency contraceptive?
Use exactly as directed on the label, or as prescribed by your doctor.
Preven emergency contraceptive must be taken as soon as possible after unprotected sex (no later than 72 hours afterward).
Call your doctor right away if you vomit within 2 hours after taking Preven emergency contraceptive. Do not take a second dose without first asking your doctor.
Visit your doctor within 3 weeks after taking Preven emergency contraceptive. A doctor should confirm that you are not pregnant, and that this medicine has not caused any harmful effects.
If your period is late by 1 week or longer after the expected date, you may be pregnant. Get a pregnancy test and contact your doctor if you are pregnant. Preven emergency contraceptive will not terminate pregnancy if the fertilized egg has attached to the uterus.
Store at room temperature away from moisture and heat.
How should this medicine be used?
Preven comes as a tablet to take by mouth. If you are taking Preven as a single tablet product , take one tablet as soon as possible within 72 hours after unprotected sexual intercourse. If you are taking Preven as a two tablet product, take one tablet as soon as possible within 72 hours after unprotected sexual intercourse and take a second dose 12 hours later. Preven works best if it is taken as soon as possible after unprotected sexual intercourse. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take Preven exactly as directed.
If you vomit less than 2 hours after you take a dose of Preven, call your doctor. You may need to take another dose of this medication.
Because you can become pregnant soon after treatment with Preven, you should continue using your regular method of birth control or begin using regular birth control immediately.
The Plan B package instructions state that you should take 1 white pill within 72 hours after unprotected sex and 1 more white pill 12 hours later. Each dose contains 0.75 mg of Preven. The two pills are identical; it does not matter which pill you take first.
However, recent research indicates that both doses can be taken at the same time up to 120 hours after unprotected sex. The pills are more effective the sooner they are taken, so take 2 Plan B pills at the same time as soon as possible after unprotected intercourse.
Avoid smoking. It can greatly increase your risk of blood clots, stroke, or heart attack while using estradiol and Preven.
Avoid exposing the patch to sunlight or tanning beds while you are wearing it on your skin.
Grapefruit may interact with estradiol and Preven and lead to unwanted side effects. Avoid the use of grapefruit products.
Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.
Many drugs can affect estradiol and Preven. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.
What is Preven emergency contraceptive?
Preven emergency contraceptive is used to prevent pregnancy after unprotected sex or failure of other forms of birth control (such as condom breakage, or missing 2 or more birth control pills).
Preven emergency contraceptive may also be used for purposes not listed in this medication guide.
Do I need a prescription for Preven-oral?
No. Most emergency contraception pills can be purchased over-the-counter or OTC (without a prescription). However, some age restrictions may apply.
Preven Brand Names
Preven may be found in some form under the following brand names:
Intrauterine administration of Preven
The Mirena system for intrauterine administration of Preven is estimated to release some 20 micrograms of the drug daily. This has been the subject of some sharply differing assessments. In a mailed questionnaire study of 1056 British women who had been treated with this product for menstrual disorders, 73% had continued using the system, having found that it provided relief; the most common adverse effect was menstrual spotting (19%) .
The possible long-term effects of a Preven-releasing intrauterine system on the endometrium and lipid profile have been examined in 142 postmenopausal women with breast cancer who took tamoxifen and were studied for 36 months. At the end of this period there were only very minor changes in serum lipids, fewer endometrial polyps, and no endometrial hyperplasia in the study group compared with a control group taking tamoxifen alone. The authors concluded that use of the Preven-releasing intrauterine system may reduce the need for investigation of adverse effects in women taking tamoxifen and may also reduce patient discomfort while improving adherence to treatment .
However, some women express a dislike for the Preven intrauterine releasing system, declaring that they have an excessive incidence of adverse reactions. When another hospital sent questionnaires to 203 British women in whom the device had been inserted over a 5-year period it was found that the continuation rate fell progressively from 85% after the first 6 months to 50% after 4 or 5 years . The median duration of use was only 270 days. The principal reasons for requesting removal were unscheduled bleeding, progestogenic adverse effects, or abdominal pain.
This may well prove to be one of the situations in which patient satisfaction with a method of treatment appears to differ markedly from one place to another, and especially between countries. Differences in the tradition of treatment or in the manner in which a physician presents a proposed therapy to the patient may be important factors determining patients’ expectations. The British report (published under the heading “Why do some people dislike it?”) needs to be set alongside an Austrian study of 180 000 users of the intrauterine system, many of them apparently very satisfied with the method. To cite a group of 13 Austrian authors: “Reliability, comfort, excellent compatibility and less severe, shorter and less painful monthly periods were the most frequently named advantages of the Preven-releasing . Medication-induced cervical priming before insertion can be carried out on a routine or selective basis (for example in nullipara, in women who have undergone cervical conisation or in women who have previously experienced painful insertion). There is, at present, no evidence of an increased rate of breast cancer … A directly comparative study with oral contraceptives in young nullipara showed excellent results for the Preven-releasing ” . A Spanish group similarly considered that the system “meets the effectiveness and tolerability criteria for being considered as a first choice treatment option for women with idiopathic menorrhagia” .
What other drugs will affect Preven emergency contraceptive?
Certain other medications can make Preven emergency contraceptive less effective, which may result in pregnancy. Ask a doctor or pharmacist if Preven emergency contraceptive is safe to use if you are using any of the following medications:
This list is not complete. Other drugs may affect Preven, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
What happens if I overdose?
Because Preven emergency contraceptive is supplied as a single tablet in an exact strength, an overdose is unlikely to occur when the Preven is used as directed. Do not take more than one tablet at the same time.