About Verapamil
Verapamil belongs to a class of drugs called calcium channel blockers.
They block calcium ions from some cell walls, inhibiting the
contraction of coronary and peripheral arteries. The reduced
electrical activity in the cardiovascular system lowers oxygen
requirements for the heart muscle, decreases the likelihood
of spasm and contraction in the arteries, and prevents the
heart from beating too rapidly or forcefully. Benefits should
be seen within 1-4 weeks of regular and consistent use.
Verapamil 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, arrhythmias (irregular heartbeat), rapid heartbeat
caused by atrial fibrillation, tachycardia, and high blood
pressure (hypertension).
Other uses for which Verapamil is acceptable include: cluster
headache reduction, halt the progression of artherosclerosis,
hypertrophic cardiomyopathy, prevention of abnormal heart
rhythm after surgery, reduces stuttering in some cases, retard
keloid formation, secondary therapy for panic attack symptoms,
or as secondary therapy for Tourette's syndrome.
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.
Verapamil is only available by prescription.
Verapamil Side Effects
Possible Side Effects: Constipation (may be frequent), diarrhea,
low blood pressure (hypotension), 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 (hives, itching, joint pain, rash), coughing,
difficulty breathing, dizziness, fatigue, flushing, headache, indigestion,
nausea, poor circulation to extremities (cold or numbness in hands
or feet), unusual conditions of the gums (bleeding, growth, tenderness),
wheezing.
Serious: Allergy (severe rash), chest pain, congestive heart
failure (rare), fainting, fluid in the lungs, liver damage, low
blood sugar (hypoglycemia), racing or irregular heartbeat, reduced
blood clotting, revealing movement disorders (rare).
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.
- Allergies: An allergic reaction to this drug in the past
is an indication that you should not use it. 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.
- Congestive Heart Failure/2nd or 3rd Degree Heart Block:
You should not use this medication.
- 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.
Verapamil 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.
- Poor Circulation: Frequently cold or tinging extremities
should be discussed with your doctor.
- Recent Heart Attack: Use with caution.
- Recent Stroke: Use with caution.
- Sick Sinus Syndrome: If your condition has not been treated
with a pacemaker, this medication should not be prescribed.
- Ventricular Tachycardia: A fast heart rate that's a result
of ventricular activity should not be treated with Verapamil,
and is a contraindication for treatment.
Verapamil 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 verapamil 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.
- Aspirin (salicylic acid, salicylates) - May lower blood
pressure too much, and can cause verapamil to build up in
the body.
- 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 verapamil,
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 verapamil.
- Biaxin (clarithromycin) - The effects of verapamil may
be increased.
- Buspar (buspirone)
- Effects may be increased when taken with verapamil.
- 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.
- Cordarone (amiodarone) - This combination may cause cardiac
arrest.
- Coumadin (warfarin)
- Increased risk of gastrointestinal hemorrhage.
- dantrolene - Can elevate blood potassium to level that
may depress heart activity.
- Digitalis glycosides - Toxicity may occur when these compounds
are combined with calcium channel blockers.
- Dilantin (phenytoin)
- May reduce the effectiveness of verapamil treatment.
- HMG-CoA reductase inhibitors (statins) - Drugs like Lescol
(fluvastatin), Lipitor
(atorvastatin), Mevacor (lovastatin), Pravachol (pravastatin),
or Zocor (simvastatin) may cause verapamil to build up in
the body.
- Hytrin (terazosin) - This combination may raise your blood
pressure.
- Lanoxin (digoxin) -
Toxicity may occur when these compounds are combined with
calcium channel blockers.
- Lithium - Toxicity and mania
may result if you use Lithium with verapamil.
- Minipres (prazosin) - Increased risk of orthostatic hypotension.
- Nicotine (chewing tobacco, cigarettes, nicotine gum or
patches) - This substance may reduce the effectiveness of
your treatment. Do not combine.
- Non-steroidal anti-inflammatories (NSAIDs) like Ibuprofen,
Indocin (indomethacin), Naprosyn (naproxen), and others,
as well as combination pain killers which contain NSAIDs,
may reduce the medication's effectiveness in reducing high
blood pressure.
- Norcuron (vecuronium) or Pavulon (pancuronium) - The muscle
weakening caused by these neuromuscular blocking agents
may be increased.
- Norpace (disopyramide) - Undesirable verapamil buildup
may occur. Increased muscle weakness may occur when these
treatments are combined.
- Oncovin (vincristine)
- Pletal (cilostazol) - Dosage adjustments may be necessary
to prevent Pletal toxicity.
- 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 verapamil in the body.
- Quinaglute (quinidine) - Calcium channel blockers increase
the risk of quinidine side effects.
- Rapamune (sirolimus) - Effects increased.
- Rifampin (Rifadin, Rimactane) - May decrease usefulness
of verapamil.
- Sandimmune (cyclosporine) - Increased risk of side effects.
- Sulfinpyrazone - Reduces verapamil's blood levels and
effectiveness.
- Synercid (dalfopristin, quinupristin) - The effects of
verapamil may be increased.
- Tagamet (cimetidine)
- Can increase verapamil'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.
- Tikosyn (dofetilide) - Dosage adjustments may be necessary
to prevent Tikosyn toxicity.
- Tricyclic antidepressants such as Asendin (amoxapine),
Anafranil (clomipramine), Elavil
(amitriptyline), Pertofrane or Norpramin (desipramine),
Sinequan (doxepin),
Tofranil (imipramine), Aventyl or Pamelor (nortriptyline),
Vivactil (protriptyline), and Surmontil (trimipramine),
may have increased side effects when combined with this
treatment.
- Versed (midazolam) - May build up to excessive levels
in the body when combined with verapamil.
- Vesanoid (tretinoin) - Effects may be increased when taken
with verapamil.
- Welchol (colesevelam) - May decrease blood levels of verapamil,
making treatment less effective.
Verapamil Dosages
This medication is available in the following dosages and forms
of delivery:
- Immediate Release (tablets): 40 mg, 80 mg, 120 mg
- Extended Release (caplets, tablets): 120 mg, 180 mg, 240 mg
- Timed Release (tablets): 100 mg, 200 mg, 300 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 480 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: 120 mg - 360 mg daily, in divided doses or one extended
release dose.
- Arrhythmia: 120 mg - 360 mg daily, in divided doses or one extended
release dose.
- Hypertension: 120 mg - 480 mg daily, in divided doses or one
extended release dose.
Verapamil Directions
If you miss a dose of Verapamil, 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
Verapamil 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.
Verapamil tablets are most comfortably taken with food. While the
immediate release tablets may be crushed into food or a beverage,
the extended release forms must be swallowed whole. Capsules may
be taken with or without food, and should be swallowed whole. Do not take this medication with
grapefruit juice, or within two hours of a calcium supplement.
Stopping this Verapamil 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 Verapamil 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 Verapamil away from children; both when storing it, and when
discarding any unused medication.
Verapamil and Pregnancy
In animal studies, this medication caused a greater incidence of
growth problems with the unborn child, but did not cause birth defects.
Verapamil 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.
Verapamil and Children
This medication has not been established as as safe and effective treatment for children.
Verapamil and Seniors
There is a greater likelihood of dizziness, fainting, falls, or weakness. Changes in thirst or urination should be reported to your doctor immediately.
Calan and Covera HS are trademarks of G. D. Searle
Isoptin is a trademark of Abbott
Verelan PM is a trademark of Schwarz
Generic Verapamil is manufactured by Geneva, Mylan, and Watson
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This document is provided for information only. It is not a substitute for consultation with a physician, 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 can say if a medication, or drug combination, is safe for you. Information intended for US residents only.
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