Propranolol

Brand names

• Apo-Propranolol
• Betachron
• Detensol
• Dom-Propranolol
• Inderal
• Inderal-LA
• Inderide [CD]
• Inderide LA [CD]
• Ipran
• Novo-Pranol
• Nu-Propranolol
• PMS-Propranolol

Usage

To treat angina, mild to moderate high blood pressure, irregular heartbeat (cardiac arrhythmias), hypertrophic cardiomyopathy (weakness of the heart muscle), heart attack, pheochromocytoma, and tremors. Also used to prevent migraine headaches.

How it works

Propranolol blocks nerve impulses to various parts of the body, which accounts for its many effects. For example, it slows the heart's rate and force of the contraction (which helps lower blood pressure), decreases the heart's oxygen requirement (which helps prevent angina), and helps stabilize heart rhythm.

Side effects

Serious

Shortness of breath, wheezing; irregular or slow heartbeat (50 beats per minute or less); pain or feelings of tightness or pressure in the chest; swelling of the ankles, feet, and lower legs; depression.

Common

Dizziness or lightheadedness, especially when rising suddenly to a standing position; decreased sexual ability; unusual fatigue, weakness, or drowsiness; insomnia.

Less common

Anxiety, irritability; constipation; diarrhea; dry eyes; itching; nausea or vomiting; nightmares or intensely vivid dreams; numbness, tingling, or prickling in the fingers, toes, or scalp.

Possible interactions

Other medicaments:

Propranolol may increase the effects of:

• other antihypertensive medicaments and cause excessive lowering of blood pressure; dose adjustments may be necessary.
• lidocaine (Xylocaine, etc.).
• quinidine (Quinaglute). Careful patient monitoring for heart failure, excessively low blood pressure and very slow heart rate is required.
• reserpine (Ser-Ap-Es, etc.) and cause sedation, depression, slowing of the heart rate and lowering of blood pressure.
• rizatriptan (Maxalt); a 5-mg starting dose and a maximum of 15 mg of rizatriptan should be used if these medicines are combined.
• verapamil (Calan, Isoptin) and cause excessive depression of heart function; monitor this combination closely.
• warfarin (Coumadin) and increase bleeding risk; more frequent INR (prothrombin time or protime) testing is needed. Warfarin dosing should be adjusted to laboratory results.

Propranolol may decrease the effects of:



• albuterol (Proventil).
• theophyllines (Aminophyllin, Theo-Dur, etc.) and reduce their antiasthmatic effectiveness.

Propranolol taken concurrently with:



• amiodarone (Cordarone) may result in abnormal heart rhythms and low pulse-these agents should not be combined.
• clonidine (Catapres) requires close monitoring for rebound high blood pressure if clonidine is withdrawn while propranolol is still being taken.
• cocaine may lead to heart attack.
• colestipol (Colestid) may decrease propranolol benefits.
• digoxin (Lanoxin) can result in severe slowing of the heart (bradycardia).
• epinephrine (Adrenalin, etc.) may cause marked rise in blood pressure and slowing of the heart rate.
• ergot derivatives may lead to excessive blood vessel constriction and cold extremities (peripheral ischemia).
• fluoxetine (Prozac) may increase the risk of slow heartbeat and sedation.
• fluvoxamine (Luvox) may increase the risk of slow heartbeat and sedation.
• insulin requires close monitoring to avoid undetected hypoglycemia.
• methyldopa (various) can lead to an excessive blood pressure increase during stress.
• nefazodone (Serzone) may decrease propranolol benefits and lead to nefazodone toxicity.
• oral antidiabetic medicaments and cause slow recovery from any low blood sugar that may occur.
• quinidine (Quinaglute) can increase adverse effects without increased therapeutic benefits.
• sertraline(Zoloft) may lead to sudden chest pain.
• venlafaxine (Effexor) may result in increased risk of propranolol toxicity.
• X-ray contrast media such as diatrizoate results in up to an eightfold increase in risk of severe allergic (anaphylactic) medicament reactions.
• zolmitriptan (Zomig) may increase risk of zolmitriptan adverse effects.
• zotepine (Nipolept) may increase risk of toxicity from both medicaments.

The following medicaments may increase the effects of propranolol:



• chlorpromazine (Thorazine, etc.).
• cimetidine (Tagamet).
• ciprofloxacin (Cipro).
• diltiazem (Cardizem).
• disopyramide (Norpace).
• furosemide or other diuretics.
• methimazole (Tapazole).
• metoclopramide (Reglan) (conventional immediate-release forms of propranolol).
• nicardipine (Cardene).
• propafenone (Rythmol) especially if doses of 150 mg a day or more of propafenone are used.
• propoxyphene (various).
• propylthiouracil (Propacil).
• ritonavir (Norvir) and perhaps other protease inhibitors.
• zileuton (Zyflo).

The following medicaments may decrease the effects of propranolol:



• antacids.
• barbiturates (phenobarbital, etc.).
• indomethacin (Indocin) and possibly other "aspirin substitutes," or NSAIDs-may impair propranolol's antihypertensive effect.
• rifampin (Rifadin, Rimactane).
• sertraline (Zoloft) may increase risk of chest pain.
• simvastatin (Zocor) by decreasing the peak blood concentration.

Foods:

Excessive fat intake can worsen existing cardiovascular disease. Talk to your doctor about a sensible diet.

Herbal medicines or minerals:

Ginseng may increase blood pressure, blunting the benefits of this medicine. Hawthorn, saw palmetto, ma huang, goldenseal, yohimbe and licorice may also cause increased blood pressure. Calcium and garlic may help lower blood pressure. Use caution and work with your doctor to make sure blood pressure is not lowered too much. Indian snakeroot has a German Commission E monograph indication for hypertension-talk to your doctor. Eleuthero root should be avoided by people living with hypertension.

Alcohol:

Alcohol may exaggerate this medicament's ability to lower blood pressure and may increase its mild sedative effect.

Tobacco smoking:

Nicotine may reduce this medicament's effectiveness in treating angina, heart rhythm disorders and high blood pressure. Smoking increases the rate of elimination of this medicament.

Exposure to heat:

Hot environments can lower blood pressure and exaggerate the effects of this medicament.

Exposure to cold:

Cold environments can enhance the circulatory deficiency in the extremities that may occur with this medicament. The elderly should take precautions to prevent hypothermia.

Heavy exercise or exertion:

It is advisable to avoid exertion that produces lightheadedness, excessive fatigue or muscle cramping. The use of this medicament may intensify the hypertensive response to isometric exercise.

Occurrence of unrelated illness:

Fever can lower blood pressure and require adjustment of dose. Nausea or vomiting may interrupt the regular dose schedule. Ask your physician for guidance.

Discontinuation:

Best to avoid sudden stopping of this medicament, especially in coronary artery disease. If possible, a gradual reduction of dose over a period of 2 to 3 weeks is recommended. Ask your physician for specific guidance.