Examples
| Generic Name | Brand Name |
|---|
| nifedipine | Adalat CC, Procardia |
Nifedipine is a
tocolytic medicine sometimes used during
preterm labor to slow uterine contractions. Nifedipine
is taken only by mouth (orally) as a tablet or capsule.
Use of
nifedipine for the treatment of preterm labor is an
unlabeled use of the drug. Nifedipine, a calcium
channel blocker, is more commonly used to treat high blood pressure and heart
disease.
How It Works
Smooth muscle tissue, like the uterus,
needs calcium to contract. Nifedipine blocks the passage of calcium into
certain tissues, relaxing the uterine muscles and smooth muscles of blood
vessels throughout the body.
Why It Is Used
Nifedipine is used for the treatment
of preterm labor when:
- Regular contractions of the uterus have thinned (effaced) the
cervix and opened (dilated) it less than
4 cm, and the mother's amniotic sac has not
broken.
- The mother is healthy.
- The fetus is alive and not in distress.
- Labor needs to be delayed for 24 to 48 hours. This is typically
necessary with
corticosteroid treatment to help fetal lungs mature.
Sometimes labor is delayed so the mother can be moved to a hospital with
special facilities for treating premature infants.
- Beta-sympathetic medicines (ritodrine and terbutaline) have not
stopped uterine contractions.
- Treatment with other tocolytic medicines was stopped because of
side effects.
How Well It Works
Small studies so far show that
nifedipine may work better than other drugs to slow or stop preterm labor, with
fewer problems for newborns.1
Side Effects
Side effects of nifedipine can
include:
- Dizziness, lightheadedness, and nervousness.
- Skin flushing or redness.
- Headache.
- Nausea.
- Muscle cramps or tremors.
- Low blood pressure in the mother and a possible decrease in the
blood supply to the fetus.
See Drug Reference for a full list of side effects. (Drug
Reference is not available in all systems.)
What To Think About
- A mother's blood pressure is checked frequently while she takes
this medicine.
- Pregnant women with liver disease should not take
nifedipine.
- Nifedipine should not be used together with magnesium
sulfate.
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