Detailed Drug Information:

DRUG CLASS AND MECHANISM: Propranolol is a beta-adrenergicblocking agent. Propranolol blocks the action of the sympathetic nervoussystem, a portion of the involuntary nervous system. The sympathetic nervous system stimulates the pace of the heart beat. By blocking the action of these nerves, propranolol reduces the heart rate and is useful intreating abnormally rapid heart rhythms. Propranolol also reduces theforce of heart muscle contraction and lowers blood pressure. By reducingthe heart rate and the force of muscle contraction, propranolol reducesheart muscle oxygen demand. Since angina occurs when oxygen demand of theheart exceeds supply, propranolol is helpful in treating angina.

PREPARATIONS: Tablets: 10 mg, 20 mg, 40 mg, 60 mg, 80 mg.Capsules (long-acting): 60 mg, 80 mg, 120 mg, 160 mg.

STORAGE: Tablets and capsules should be stored at roomtemperature in a tightly closed container.

PRESCRIBED FOR: Propranolol is prescribed for patients with highblood pressure (hypertension). It is also used to treat chest pain (anginapectoris) related to coronary artery disease. Propranolol is also usefulin slowing and regulating certain types of abnormally rapid heart rates(tachycardias). Other uses for propranolol include the prevention ofmigraine headaches and the treatment of certain types of tremors (familialor hereditary essential tremors). Propranolol is commonly used in persons with thyrotoxicosis (high blood levels of thyroidhormone) to slow down rapid heart rate and tremor.

DOSING: Should be taken before meals or at bedtime.

DRUG INTERACTIONS: Propranolol can aggravate breathingdifficulties in patients with asthma, chronic bronchitis, or emphysema. Inpatients with existing slow heart rates (bradycardias) and heart blocks(defects in the electrical conduction of the heart), propranolol can causedangerously slow heart rates, and even shock. Propranolol reduces theforce of heart muscle contraction and can aggravate symptoms of heartfailure. Calcium channel blockers, digoxin (Lanoxin), and haloperidol (Haldol) can cause lowering of blood pressure and heart rate to dangerouslevels when administered together with propranolol. In patients withcoronary artery disease, abruptly stopping propranolol can suddenly worsenangina, and occasionally precipitate heart attacks. If it is necessary todiscontinue propranolol, its dosage can be reduced gradually over severalweeks. Propranolol can mask the early warning symptoms of low blood sugar(hypoglycemia), and should be used with caution in patients receivingtreatment for diabetes. Safe use in children has not been established. Itis not habit forming.

Many medicines interact with propranolol. Alcohol and aluminumcontaining antacids reduce the absorption of propranolol. Phenytoin (Dilantin), phenobarbital, and rifampin reduce the blood levels ofpropranolol. Cimetidine (Tagamet) and chlorpromazine increase the bloodlevels of propranolol. Propranolol increases the blood levels of certainmedicines such as theophylline and lidocaine.

PREGNANCY: Safe use during pregnancy has not been established.

SIDE EFFECTS: Propranolol is generally well tolerated, and side effects are mild and transient. Rare side effects include abdominal cramps, diarrhea, constipation, fatigue, insomnia, nausea, depression, dreaming, memory loss, fever, impotence, lightheadedness, slow heart rate,low blood pressure, numbness, tingling, cold extremities, sore throat, andshortness of breath or wheezing.