Nifedipine (Procardia) for Angina pectoris

Type of Drug: Calcium channel blocker.

Prescribed for: Angina pectoris; Prinzmetal’s angina. In addition, sustained- release Nifedipine is used for 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, gallbladder and kidney stone attacks, and severe high blood pressure associated with pregnancy (preterm labor).

Brand Name: Adalat, Adalat CC, Procardia, Procardia XL.


General Information of Nifedipine (Procardia)

Nifedipine was the first of many 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 effect 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 first started, when it is increased, or if it is abruptly stopped. Studies have shown that people taking calcium channel blockers (usually those taken several times a day and not those that are taken only once daily) have a greater chance of having a heart attack than people taking beta blockers or other medicines for the same purposes. Discuss this with your doctor to be sure you are receiving the best possible treatment.

Congestive heart failure has rarely developed in people taking Nifedipine. This happens because the drug can reduce the efficiency of an already compromised heart.

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. Cali 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. Kidney disease can affect the release of Nifedipine from your body. Your doctor should take these into account when determining your Nifedipine dosage.

Possible Side Effects of Nifedipine (Procardia)

Nifedipine side effects are generally mild and rarely cause people to stop taking the drug.

  • Most common: swelling of the ankles, feet, and legs; dizziness or light-headedness, flushing; a feeling of warmth; and nausea.
  • Less common: nervousness; headache; weakness, shakiness, or jitteriness; giddiness; muscle cramps, inflammation, and pains; nervousness; mood changes; heart palpitations; heart failure; heart attack; difficulty breathing; coughing; fluid in the lungs; wheezing; stuffy nose; fever and chills; and sore throat.
  • Rare: 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. Low blood pressure can also result from taking Nifedipine with Fentanyl, a narcotic pain reliever.
  • 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 Cyclosporine, Digoxin, and Theophylline products, increasing the chances of side effects with those drugs.

Nifedipine (Procardia) Food Interactions

Nifedipine can be taken without regard to food or meals. Avoid drinking grapefruit juice if you are taking this medicine.

Usual Dose

10 to 30 mg 3 times a day of regular Nifedipine. No patient should take more than 180 mg per day. The usual dose for the sustained-release version of Nifedipine (Procardia XL, Adalat CC) is 30 to 60 mg 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, worsening angina pains, swelling in the hands or feet, difficulty breathing, increased heart pains, or dizziness or light headedness, or if other side effects are particularly 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 Procardia XL, be sure not to break or crush the tablets. You may notice an empty tablet in your stool. This is not a 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, and take it 3 or more times a day, take it as soon as you remember. If it is almost time for your next regularly scheduled dose, take the forgotten dose and space the rest evenly throughout the remainder of the day.

If you take Nifedipine twice a day and forget to take a dose, take it as soon as you remember. If it is almost time for your next dose, skip the forgotten dose and continue with your regular schedule. Do not take a double dose of Nifedipine.

Nifedipine (Procardia) Special Populations

Pregnancy/Breast-feeding
Nifedipine crosses into the blood circulation of a developing fetus. It has been used to treat severe high blood pressure associated with pregnancy without causing any unusual effect on the fetus. Nevertheless, pregnant women, or those who might become pregnant while taking this drug, should not take it without their doctor’s 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 and may develop low blood pressure because it takes longer to pass out of their bodies. Follow your doctor’s directions and report any side effects at once.