About Nifedipine
Nifedipine belongs to a class of drugs known as calcium channel
blockers. They work by blocking calcium ions from some cell walls,
inhibiting the contraction of coronary and peripheral arteries.
The reduced electrical activity in the cardiovascular system results
in lowered oxygen requirements for the heart muscle, decreased likelihood
of spasm and contraction in the arteries, and prevents the heart
from exerting itself too rapidly or forcefully. Benefits should
be seen within 1-4 weeks of consistent use.
This medication is primarily prescribed to treat: angina (Prinzmetal's
variant angina) not caused by exertion, angina caused by exertion
in those who do not respond to treatment with beta blockers or nitrates,
and high blood pressure (hypertension). The extended release form
of the medication is generally recommended for these conditions,
the immediate release form may not be safe.
Other uses for which it is acceptable include: halt the progression
of artherosclerosis in early stages, reduces symptoms of Raynaud's
syndrome (cold, tingling, or numb extremities), partial therapy
for pulmonary hypertension, decreases heart attack risk after coronary
bypass surgery, may reduce symptoms of neurological pain disorders,
can reduce over-reaction to cold.
Medication for high blood pressure or other cardiovascular problems
may have to continue for the duration of the patient's life, there
are currently no treatments that will reverse these conditions.
It's important that medication prescribed to treat these ailments
be taken regularly, as there may be no obvious symptoms before serious
damage is done to the body.
Nifedipine is only available by prescription.
Nifedipine Side Effects
Possible Side Effects: Change in menstrual cycle, constipation,
diarrhea, dizziness, fast heartbeat, flushing or warmth, headache,
low blood pressure (hypotension), nausea, sweating, swollen feet
or ankles, unusual tiredness.
Adverse Side Effects: Report any of the following infrequent
to rare symptoms to your doctor. If you experience any serious side
effects, seek medical treatment.
Mild
: Allergy (fever, hives, itching, rash), coughing, difficulty
breathing, dizziness, fatigue, flushing, headache, indigestion,
muscle cramps, nausea, poor circulation to extremities (cold or
numbness in hands or feet), reversible infertility in men, sleep
disorder, shortness of breath, tremors, unusual conditions of the
gums (bleeding, growth, tenderness), wheezing.
Serious
: Allergy (severe rash), bleeding or swollen gums,
chest pain, congestive heart failure (rare), decreased circulation
in fingers, fainting induced by low blood pressure, fluid in the
lungs, kidney damage, liver damage, low blood sugar (hypoglycemia),
more frequent angina, pain or swelling in joints, racing or irregular
heartbeat, reduced blood clotting, revealing movement disorders
(rare), trouble seeing.
Cautions: This medication may not be suitable for everyone.
Discuss any history of the following conditions with your doctor,
and carefully examine your treatment options.
- 71 Years Of Age Or Older: Do not use the immediate release
form of this drug.
- Allergies: An allergic reaction to this drug in the past
is an indication that you should not use it. If you develop a
skin condition while undergoing treatment, tell your doctor at
once. Inform you doctor if you have had a poor response to another
calcium channel blocker, or have any other allergies (food, dye,
medications).
- Aortic Stenosis: Speak to a specialist regarding treatment
options, this medication will probably not be the correct treatment
for you.
- Circulatory or Heart Conditions: Any history of heart
attack, stroke, congestive heart failure, heart rhythm disorders,
or any other condition of the circulatory system needs to be discussed
with your prescribing physician.
- Congestive Heart Failure/2nd or 3rd Degree Heart Block:
You should not use this medication.
- Diabetes: Consult your specialist.
- Gangrene: Discuss use with your doctor.
- Glaucoma: If you have glaucoma, and must administer any
of the following beta blocker eye drops, consult your physician
regarding possible interactions: Betagan (levobunolol), Betoptic
(betaxolol), OptiPranolol (metipranolol), or Timoptic (timolol).
- Heart Medications: If you take any other medication for
a cardiovascular condition, there may be a risk of significant,
possibly dangerous, drug interactions.
- Kidney or Liver Disease: Your doctor may decrease the
normal dose from 20-75%, depending on the severity of the condition.
Nifedipine should not be prescribed for individuals with active
liver disease. In rare cases, this drug has caused liver damage,
and should be prescribed with caution to individuals whose livers
have been damaged by other drugs.
- Low Blood Pressure (Hypotension): Do not use.
- Muscular Dystrophy: Consult your specialist.
- Poor Circulation: Frequently cold or tinging extremities
should be discussed with your doctor.
- Recent Heart Attack: Use with caution.
- Recent Stroke: Use with caution.
Nifedipine Interactions
This medication may interact with other treatments. Always keep
your prescribing physician informed about any prescription or over
the counter preparations you may use. While some of the following
medications may be used with nifedipine even though there is a possibility
for interaction, some should not be mixed. Your doctor will have
to make this determination based on the necessity of treatment,
the possibility of dosage adjustments, and your medical history.
- Alcohol - Use with caution as directed by your doctor.
Alcohol may lower blood pressure too much, and its side
effects may be more pronounced when used with this medication.
- Anti-diabetic drugs or Insulin - This combination may
result in undesirably low blood sugar, regular testing for
hypoglycemia is recommended.
- Azole antifungals - Diflucan
(fluconazole), Nizoral
(ketoconazole), Sporanox
(itraconazole), and possibly others, may cause nifedipine
toxicity.
- Beta Blockers - Drugs like Blocadren (timolol), Cartrol
(carteolol), Corgard (nadolol), Inderal
(propranolol), Kerlone (betaxolol), Levatol (penbutolol),
Lopressor (metoprolol),
Normodyne (labetalol), Sectral (acebutolol), Sotacor (sotalol),
Tenormin (atenolol),
Trasicor (oxprenolol ), or Visken (pindolol) may alter heart
rhythm and blood pressure undesirably when used with calcium
channel blockers. The beta blocker drops administered by
eye as a treatment for glaucoma may also interact with nifedipine,
speak to your doctor if you take Betagan (levobunolol),
Betoptic (betaxolol), OptiPranolol (metipranolol), or Timoptic
(timolol) drops.
- Bronchodilators of the xanthine (thioxanthine) class (Aminophylline,
Dyphylline, Oxtriphylline, Somophyllin, Theo-Dur,
etc...) - May be toxic when mixed with nifedipine, as well
as reducing benefits of treatment.
- Calcium - Supplemental calcium may reduce the effectiveness
of calcium channel blockers. Take any vitamin supplement
containing calcium either 2 hours before, or 2 hours after,
taking your medicine.
- Cardizem (diltiazem)
- Toxic build ups of nifedipine may occur.
- Cerebyx (fosphenytoin) or Dilantin
(phenytoin) - May build up to toxic levels in the body
when used with nifedipine treatment.
- Cordarone (amiodarone) - This combination may cause cardiac
arrest.
- Coumadin (warfarin)
- Increased risk of gastrointestinal hemorrhage.
- Digitalis glycosides - Toxicity may occur when these compounds
are combined with calcium channel blockers.
- Lanoxin (digoxin) -
Toxicity may occur when these compounds are combined with
calcium channel blockers.
- Magnesium - May further lower blood pressure, consult
your doctor about vitamin supplements and dosage adjustments.
- Nicotine (chewing tobacco, cigarettes, nicotine gum or
patches) - This substance may reduce the effectiveness of
your treatment. Do not combine.
- Norpace (disopyramide) - Undesirable nifedipine buildup
may occur. Increased muscle weakness may occur when these
treatments are combined.
- Oncovin (vincristine) - May build up to toxic levels.
- Prograf (tacrolimus) - Effects of Prograf may be increased.
- Pronestyl (procainamide) - Calcium channel blockers can
increase the effects of this drug.
- Protease inhibitors such as Agenerase (amprenavir), Norvir
(ritonavir), and perhaps others, may lead to higher levels
of nifedipine in the body.
- Quinaglute (quinidine) - Calcium channel blockers increase
the risk of quinidine side effects.
- Rifampin (Rifadin, Rimactane) - May decrease usefulness
of nifedipine.
- Sandimmune (cyclosporine) - Increased risk of side effects.
- Synercid (dalfopristin, quinupristin) - The effects of
nifedipine may be increased.
- Tagamet (cimetidine)
- Can increase nifedipine's effects.
- Tambocor (flecainide) - Calcium channel blockers can increase
the effects of this drug.
- Tegretol (carbamazepine)
- Tegretol may build up to toxic levels in the body.
- Zantac (ranitidine)
- May increase nifedipine side effects.
Nifedipine Dosages
This medication is available in the following dosages and forms
of delivery:
- Immediate Release (capsules): 10 mg, 20 mg
- Extended Release (tablets): 30 mg, 60 mg, 90 mg
The following are general guidelines for adults, your doctor will
need to give you a specific dosage depending on your body size and
medical history. Dosage should not generally exceed 90 mg daily.
Once daily dosing should generally be taken at bedtime. Your doctor
will probably start with the minimum dose and gradually increase
as needed, follow your doctor's instructions for use exactly.
- Angina: 30 mg - 60 mg daily, in divided
doses or one extended release dose.
- Hypertension: 30 mg - 60 mg daily, in
divided doses or one extended release dose.
Nifedipine Directions
If you miss a dose of Nifedipine, take it as soon as you remember,
unless it is almost time for the next one. In that case, skip the
missed dose and go back to your schedule. Taking double doses of
Nifedipine is not recommended. This medication is most effective
when it is used consistently according to the schedule recommended
by your doctor. The extended release forms are usually taken at
bedtime to ensure that peak drug levels occur in the morning, when
there is a greater likelihood of heart attack.
Notify any health care personnel that you take this medication.
Carry a card or alert bracelet in case you should require emergency
services. Nitroglycerin, or another nitrate medication, is a safe
treatment for any acute angina episodes.
Nifedipine tablets are most comfortably taken with food. All forms
of this medication should be swallowed whole. Do not take this medication
with grapefruit juice, or within two hours of a calcium supplement.
Stopping this Nifedipine abruptly may lead to rebound angina. Decrease
your dose gradually according to the advice of your doctor if you
must stop treatment for any reason.
Store Nifedipine away from direct light and heat. Store in a dry
location; avoid storing it in the bathroom, near sinks, or other
areas where it may become damp. Do not use after the expiration
date.
Keep Nifedipine away from children; both when storing it, and when
discarding any unused medication.
Nifedipine and Pregnancy
In animal studies, this medication caused a greater incidence of
growth problems with the unborn child, but did not cause birth defects.
Nifedipine should not be used at all during the first trimester,
consult with your doctor about treatment during the rest of your
pregnancy. Inform you doctor if you are planning a pregnancy, use
effective contraception while taking.
This drug only appears in very small quantities in breast milk.
If you wish to combine treatment with breastfeeding, consult with
your doctor and monitor your child's condition.
Nifedipine and Children
This medication has not been established as as safe and effective treatment for children.
Nifedipine and Seniors
The use of the immediate release form of this drug increases
the risk of death by all causes when used by individuals over the
age of 71, compared to all other hypertension treatments, including
other calcium channel blockers.
There is a greater likelihood of dizziness, fainting, falls, or
weakness. Changes in thirst or urination should be reported to your
doctor immediately.
Procardia and Procardia XL are trademarks of Pfizer
Adalat and Adalat CC are trademarks of Bayer
Nifedipine Extended Release is a trademark of Mylan
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The information contained in this document is provided for educational purposes
and information only. It is not a
substitute for consultation with a physician or Health professional, either to diagnose
symptoms or prescribe treatment. Any dosages mentioned are general
guidelines only, please follow the directions of your doctor or
pharmacist exactly when taking medication. We have made every effort to
ensure that this information is accurate, but only your doctor,
physician or Health professional can say
if a medication, a drug alternative or drug combination, is safe for you. Information
intended for US residents only.
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