Nifedipine
Brand names Adalat, Adalat Retard, Adipine, Angiopine, Calcilat, Coracten, Nifensar XL, Tensipine MR, and others
Used in the following combined preparations Beta-Adalat, Tenif
general information
Nifedipine belongs to a group of drugs known as calcium channel blockers, which interfere with conduction of signals in the muscles of the heart and blood vessels.
Nifedipine is given for the treatment of angina, as a regular medication to help prevent attacks as well as for the immediate relief of pain during an attack. it can be used safely by asthmatics, unlike some other antiangina drugs (such as beta blockers).
Nifedipine is also widely used to reduce high blood pressure and is often helpful in improving circulation to the limbs in the treatment of disorders such as Raynaud’s disease.
In common with other drugs of its class, it may cause blood pressure to fall too low, and may occasionally cause disturbances of heart rhythm. In rare cases, angina worsens as a result of taking nifedipine, and another drug must be substituted.
quick reference
Drug group Anti-angina drug and antihypertensive drug
Overdose danger rating Medium
Dependence rating Low
Prescription needed Yes
Available as generic Yes
information for: users
Your drug prescription is tailored for you.
Do not alter dosage without checking with your doctor.
How taken
Tablets, capsules, SR-tablets/capsules.
Frequency and timing of doses
3 x daily; 1-2 x daily (SR-preparations). For angina attacks: a capsule may be bitten and the liquid kept in the mouth or swallowed.
Adult dosage range
15-90mg daily.
Onset of effect
30-60 minutes. When capsules are bitten effects may be felt within minutes.
Duration of action
6-24 hours.
Diet advice
None
Storage
Keep in a closed container in a cool, dry place out of the reach of children. Protect from light.
Missed dose
Take as soon as you remember, or when . needed. If your next dose is due within 3 hours, take a single dose now and skip the next.
Stopping the drug
Do not stop the drug without consulting your doctor; symptoms may recur.
Exceeding the dose
An occasional unintentional extra dose is unlikely to cause problems. Large overdoses may cause dizziness. Notify your doctor.
possible adverse effects
Nifedipine can cause a variety of minor adverse effects. Dizziness, especially on rising, may be caused by an excessive reduction in blood pressure. Patient’s with angina may notice an increase in the severity or frequency of attacks after starting nifedipine treatment. This should always be reported to your doctor. Sometimes an adjustment in dosage or a change of drug may be necessary.
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Symptom/effect
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Frequency
Common
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Rare
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Discus doctor
Only if severe
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with
In all cases
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Stop taking drug now
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Call
doctor
now
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Headache
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•
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■
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Dizziness/fatigue
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•
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■
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Flushing
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•
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■
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Ankle swelling
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•
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■
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Frequency in passing urine
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•
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■
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Increased angina
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•
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■
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▲
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1
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interactions
Antihypertensive drugs
Nifedipine may increase the effects of these drugs.
Phenytoin
Nifedipine may increase levels of phenytoin.
Digoxin
Blood levels of digoxin may be increased when it is taken with nifedipine.
special precautions
Be sure to tell your doctor if:
▼ You have long-term liver or kidney problems.
You have heart failure.
You have diabetes.
▼ You are taking other medications.
Pregnancy
▼ Not usually prescribed. The drug may cause abnormalities in the developing fetus and delay labour. Discuss with your doctor.
Breast-feeding
▼ The drug passes into the breast milk and may affect the baby. Discuss with your doctor.
infants and children
▼ Not recommended.
Over 60
▼ Increased likelihood of adverse effects. Reduced dose may therefore be necessary.
Driving and hazardous work
▼ Avoid such activities until you have learned how nifedipine affects you because the drug can cause dizziness as a result of lowered blood pressure.
Alcohol
▼ Avoid. Alcohol may further reduce blood pressure, causing dizziness or other symptoms.
prolonged use
No problems expected.
