Emergency Contraception
Name
postcoital contraception problems
Synonyms
emergency contraception, morning-after-pill, contraception - morning after pill
General
description
Various regimens of oral hormones are used within 72 hours of intercourse or an intrauterine contraceptive device is inserted within 7 days of intercourse. The oral regimens include estrogen alone (high dose) or estrogen plus progestin in
oral contraceptive pills, or just progestin alone all given within 72 hours of unprotected intercourse. These regimens are felt to reduce the expected rate of pregnancy from a random sexual intercourse episode from about 7-8% to 2-3%. The major side effects
are nausea and vomitting. The IUCD insertion is more effective and results in less than a 1% pregnancy rate. The progestin only pill, levonorgestrel, 0.75 mg dose within 72 hours after unprotected intercourse, and a second 0.75 mg dose 12 hours after the first dose, also seems to reduce the pregnancy rate to about 2%.
Is it common?
Nausea 30-50%, vomitting 15-20% with the estrogen only and estrogen plus progestin (Preven®). The newer progestin only pill, levonorgestrel (Plan B®) has lower rates of nausea and vomitting.
An intrauterine device has the disadvantage of requiring a skilled person to insert it and a slight risk of infection especially if a sexually transmitted disease is possible with the sexual intercourse exposure.
Differentiating
features
Side effects coincide usually within one hour of taking the regimen by mouth and can be lessened with an anti-nausea medication. Uterine cramps and some light bleeding occur immediately with IUCD insertion and may last from 15-20 minutes to 24 hours or more. The cramps are treatable with non steroidal anti-inflammatory drugs, e.g., naproxen sodium (Alleve®, two tabs) given just prior or after insertion.
Other features
headaches, breast tenderness, dizziness, fluid retention, menstrual delay or
intermenstrual bleeding with the hormones.
Cause
The high estrogen doses of various regimens produce direct gastric
irritation. Different regimens include:
Plan B®, levonorgestrel, 0.75 mg tab immediately then 0.75 mg tab 12 hours later
Preven®, two blue tabs immediately then two more tablets 12 hours later
Levlite® five tabs immediately then five more tablets 12 hours later
Levora® four tabs immediately then four more tablets 12 hours later
Levlen® four tabs immediately then four more tablets 12 hours later
LoOvral® four tabs immediately then four more tablets 12 hours later
Nordette® four tabs immediately then four more tablets 12 hours later
Ovral® two tabs immediately then two more tablets 12 hours later
Trilevlen® four yellow tabs immediately then four more yellow tablets 12 hours later
Triphasil® four yellow tabs immediately then four more yellow tablets 12 hours later
Trivora® four pink tabs immediately then four more pink tablets 12 hours later
Conjugated estrogens (Premarin®) 10 mg each day for 5 days
Estrone® 5 mg twice a day for 5 days
Copper IUCD insert within 5 to 7 days of exposure
Unnecessary
studies
gastrointestinal x-rays
Natural history
untreated
nausea, vomitting and other symptoms subside after about 12 hours
Goals of
therapy (Rx)
Prevent or lessen the incidence of nausea and vomitting
1st choice therapy
levonorgestrel .75 mg once followed by a second dose 12 hours later (Plan B®) for the emergency contraception
promethazine hydrochloride (Phenergan®) 25 mg orally about one hour prior
to the hormonal therapy. clear liquid diet for prevention of nausea
Other therapies used
Anti-nausea medications such as promethazine (e.g., Phenergan®).
Treatments to
avoid
Other medications that act as gastric irritants.
Reason for Rx
choices
Progestin only pills or oral contraceptives (birth control pills) are most often used rather than
estrogens alone since the estrogen doses are less and therefore
better tolerated. Levonorgestrol alone (Plan B®) has been effective and is probably the treatment of choice. Making emergency
contraception available without prescription improves its use and pregnancy prevention.
References
Morgan KW, Deneris A
Emergency contraception: preventing unintended pregnancy.
Nurse Pract 1997 Nov;22(11):34-36
Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Task Force on Postovulatory Methods of Fertility Regulation.
Lancet 1998 Aug 8;352(9126):428-433
Glasier A, Baird D
The effects of self-administering emergency contraception.
N Engl J Med 1998 Jul 2;339(1):1-4
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