Nifedipine

BRAND NAMES

Adalat, 10 mg

Adalat 5 mg

Adalat PA 10 mg

Adalat PA 20 mg

Adalat XL 30 mg

Adalat XL 60 mg

(Also available in generic form)

TYPE OF DRUG

Calcium channel blocker.

PRESCRIBED FOR

Angina pectoris; Prinzmetal's angina; high blood pressure.

Nifedipine has also been prescribed to prevent migraine headaches and to treat

asthma, heart failure, Raynaud's disease, disorders of the esophagus, gall bladder and

kidney stone attacks, and severe high blood pressure associated with pregnancy

(preterm labor).

GENERAL INFORMATION

Nifedipine is one of a growing number of calcium channel blockers to be marketed in

the United States. Calcium channel blockers work by blocking the passage of calcium

into heart and smooth muscle. Since calcium is an essential factor in muscle

contraction, any drug that affects calcium in this way will interfere with the contraction

of these muscles. When this happens the amount of oxygen used by the muscles is

also reduced. Therefore, Nifedipine is used in the treatment of angina, a type of heart

pain related to poor oxygen supply to the heart muscles. Also, Nifedipine dilates

(opens) the vessels that supply blood to the heart muscles and prevents spasm of these

arteries. Nifedipine affects the movement of calcium only into muscle cells; it does not

have any affect on calcium in the blood.

Nifedipine capsules contain liquid medicine. In cases where the drug is needed in the

blood as rapidly as possible, the capsules may be punctured and their contents

squeezed under the tongue; medicine is rapidly absorbed into the blood in this manner.

Thus, Nifedipine capsules are useful in situations where extremely high blood

pressure must be rapidly lowered. Some researchers feel that biting the capsule in

your mouth and swallowing the contents gets the medicine into your blood even faster

than keeping it under the tongue.

CAUTIONS AND WARNINGS

Nifedipine may cause unwanted low blood pressure in some people taking it for

reasons other than hypertension.

Patients taking a beta-blocking drug who begin taking Nifedipine may develop heart

failure or increased angina pain. Angina pain may also increase when your Nifedipine

dosage is increased.

Do not take this drug if you have had an allergic reaction to it in the past.

Nifedipine may interfere with one of the mechanisms by which blood clots form,

especially if you are also taking Aspirin. Call your doctor if you develop unusual

bruises, bleeding, or black-and-blue marks.

People with severe liver disease break down Nifedipine much more slowly than

people with less severe disease or normal livers. Your doctor should take this into

account when determining your Nifedipine dosage.

PREGNANCY/BREAST-FEEDING

Nifedipine crosses into the blood circulation of a developing baby. It has been used to

treat severe high blood pressure associated with pregnancy and not caused any

unusual effect on the baby. Nevertheless, pregnant women, or those who might

become pregnant while taking this drug, should not take it without their doctors'

approval. When the drug is considered essential by your doctor, the potential risk of

taking the medicine must be carefully weighed against the benefit it might produce.

Small amounts of Nifedipine may pass into breast milk, but the drug has caused no

problems among breast-fed infants. You must consider the potential effect on the

nursing infant if breast-feeding while taking this medicine.

SENIORS

Older adults are more sensitive to the effects of this drug because it takes longer to

pass out of their bodies. Follow your doctor's directions and report any side effects at

once.

POSSIBLE SIDE EFFECTS

Common side effects are dizziness; light-headedness; flushing; a feeling of warmth;

headache; weakness; nausea; muscle cramps, inflammation, and pains; swelling of the

arms or legs; nervousness; mood changes; heart palpitations; heart failure; heart attack;

difficulty breathing; coughs; fluid in the lungs; wheezing; stuffy nose; and sore throat.

Less common side effects include low blood pressure, unusual heart rhythms, angina

pains, fainting, shortness of breath, diarrhea, cramps, constipation, stomach gas, dry

mouth, taste changes, frequent urination (especially at night), stiffness and

inflammation of the joints, arthritis, shakiness, jitteriness, psychotic reaction, anxiety,

memory loss, paranoia, hallucinations, tingling in the hands or feet, tiredness, muscle

weakness, liver inflammation, blurred vision, ringing or buzzing in the ears, difficulty

sleeping, unusual dreams, respiratory infections, anemia, bleeding, bruising,

nosebleeds, swollen gums, weight gain, reduced white-blood-cell counts, difficulty

maintaining balance, itching, rash, hair loss, painful breast inflammation, unusual

sensitivity to the sun, severe skin reactions, fever, sweating, chills, and sexual

difficulties. Nifedipine can cause increases in certain blood-sugar and some enzyme

tests.

DRUG INTERACTIONS

Nifedipine may interact with beta-blocking drugs to cause heart failure, very low blood

pressure, or an increased incidence of angina pain. However, in many cases these

drugs have been taken together with no problem.

Nifedipine may cause unexpected blood pressure reduction in patients already taking

medicine to control their high blood pressure through interaction with other

antihypertensive drugs.

Cimetidine and Ranitidine increase the amount of Nifedipine in the blood and may

account for a slight increase in Nifedipine's effect.

The combination of Quinidine (for abnormal heart rhythm) and Nifedipine must be

used with caution because it can produce low blood pressure, very slow heart rate,

abnormal heart rhythms, and swelling in the arms or legs.

Nifedipine can, rarely, increase the effects of oral anticoagulant (blood-thinning) drugs.

Nifedipine can increase the effects of Theophylline products (for asthma and other

respiratory problems).

FOOD INTERACTIONS

Nifedipine can be taken without regard to food or meals.

USUAL DOSE

30 to 120 milligrams per day of regular Nifedipine. No patient should take more than

180 milligrams per day.

The usual dose for the sustained-release version of Nifedipine (Adalat XL) is 30 to

60 milligrams taken once a day.

Do not stop taking Nifedipine abruptly. The dosage should be gradually reduced over

a period of time.

OVERDOSAGE

Overdose of Nifedipine can cause low blood pressure. If you think you have taken an

overdose of Nifedipine, call your doctor or go to a hospital emergency room.

ALWAYS bring the medicine bottle.

SPECIAL INFORMATION

Call your doctor if you develop constipation, nausea, very low blood pressure,

swelling in the hands or feet, difficulty breathing, increased heart pains, or dizziness or

light-headedness or if other side effects are particulary bothersome or persistent.

If you are taking Nifedipine for high blood pressure, be sure to continue taking your

medicine and follow any instructions for diet restriction or other treatments. High blood

pressure is a condition with few recognizable symptoms; it may seem to you that you

are taking medicine for no good reason. Call your doctor or pharmacist if you have any

questions.

If you take Adalat XL be sure not to break or crush the tablets. You may notice an

empty tablet in your stool. This is not cause for alarm, because the medicine is

normally released from the sustained-release tablet without actually destroying it.

It is important to maintain good dental hygiene while taking Nifedipine and to use

extra care when using your toothbrush or dental floss because of the chance that the

drug will make you more susceptible to some infections.

If you forget a dose of Nifedipine, take it as soon as you remember. If it is almost time

for your next regularly scheduled dose, skip the forgotten dose and continue with your

regular schedule. Do not take a double dose.