Carvedilol
Generic Name
Carvedilol (car-VAY-dih-lol)
Brand Names
Coreg Coreg CR
Type of Drug Alpha-beta-adrenergic blocker.
Prescribed For
Heart failure, high blood pressure, angina pain, and cardiomyopathy.
General Information
Carvedilol was the first beta blocker approved for heart failure. It is also the only beta blocker approved for severe heart failure.
Carvedilol blocks both the alpha- and beta-adrenergic portions of the central nervous system. This dual action reduces the amount of blood pumped with each heartbeat and also decreases the risk of tachycardia (very rapid heartbeat). Carvedilol’s beta-blocking effects begin within an hour of taking the first dose; maximum blood-pressure-lowering occurs after 1 or 2 weeks. The drug also causes blood vessels to dilate (widen), allowing the heart to pump blood more efficiently.
Cautions and Warnings
Do not take carvedilol if you are allergic or sensitive to any of its ingredients, or if you have AV block, sick sinus syndrome or severe bradycardia (slow heart rate) without the use of a pacemaker.
Carvedilol should not be taken 13y patients with bronchial disease, qQQkVaS thronic bronchitis, emphysema, or asthma.
Carvedilol therapy should not be stopped suddenly due to the risk of worsening the heart condition.
In studies, carvedilol caused mild and reversible liver injury in about 1 of every 100 people who took it. Those with severe liver disease should not take this medication. Call your doctor at once if you develop signs of liver damage (symptoms include severe itching, dark-colored urine, flu-like symptoms, appetite loss, and yellowing of the skin or whites of the eyes).
Check with your doctor about continuing carvedilol if you are to receive general anesthesia; heart function that is depressed by anesthetics can worsen if carvedilol is used at the same time.
Make sure your doctor knows if you have diabetes. Carvedilol can mask signs of low blood sugar and may increase the effects of insulin or oral antidiabetes drugs, making it more difficult to recover from the effects of low blood sugar.
Carvedilol can mask symptoms of an overactive thyroid gland. Abruptly stopping carvedilol can trigger an attack of hyperthyroidism.
Possible Side Effects
Most side effects are considered mild or moderate.
✓ Most common: dizziness, sleepiness or sleeplessness, diarrhea, abdominal pain, slow heartbeat, dizziness when rising from a sitting or lying position, swelling of the hands or feet, sore throat, breathing difficulties, tiredness, back pain, urinary infection, and viral infection.
✓ Less common: extra heartbeats; palpitations; blood-pressure changes; fainting; reduced blood supply to the arms and legs (symptoms include aches, cramps, pain, or tiredness on walking, or pain in the foot, thigh, hip, or buttocks); tingling in the hands or feet; reduced sensation; depression; nervousness; constipation; gas; liver irritation; cough; impotence and reduced sex drive in men; itching; rash; visual difficulties; ringing or buzzing in the ears; high blood cholesterol, sugar, or uric acid; anemia; weakness; hot flushes; leg cramps; dry mouth; not feeling well; sweating; and muscle ache.
✓ Rare: Rare side effects can affect the heart, mental status, the respiratory tract, the urinary tract, and the kidney. It can also cause hair loss, weight gain, high blood-triglyceride levels, low blood-platelet counts, and sugar in the urine. Contact your doctor if you experience any side effect not listed above.
Drug Interactions
• Carvedilol increases the effects of insulin and oral antidiabetes drugs. People taking this combination must monitor their blood sugar levels regularly. Call your doctor if there is any change from your normal pattern.
• Carvedilol increases the effects of verapamil, diltiazem, and similar calcium-channel blocking drugs.
• Monoamine oxidase inhibitor antidepressants may increase the effects of carvedilol.
• Carvedilol increases the blood-pressure-lowering effect of clonidine. People taking this combination may need less clonidine to control their pressure.
• Carvedilol increases the amount of digoxin in the blood by about 15%. Your digoxin dosage may have to be adjusted.
• Cimetidine increases the amount of carvedilol absorbed into the blood by about 30%, but the importance of this interaction is not clear.
• Rifampin reduces the amount of carvedilol in the blood by about 70%. Dosage adjustment is necessary.
• Do not consume alcohol (including medicines that contain alcohol) within 2 hours of taking carvedilol.
Food Interactions
Take carvedilol with food to reduce the risk of dizziness or fainting.
Usual Dose
Heart Failure
Adult: 3.125 mg twice a day for 2 weeks. Dose may be doubled every 2 weeks to the highest level tolerated. Maximum daily dosage is 25 mg twice a day in people weighing less than 187 lbs., and 50 mg twice a day in people who weigh more.
High Blood Pressure and Cardlomyopathy
Adult: 6.25 mg twice a day to start, increased to 25 mg twice a day if needed.
Senior: Seniors may require smaller doses than younger adults. Child (under age 18): not recommended.
Overdosage
~3%rdose may lead to very low blood pressure (symptoms include dizziness and fainting), slow heartbeat and other cardiac symptoms, including shock and heart attack, breathing difficulties, bronchial spasm, vomiting, periods of unconsciousness, and seizures. Overdose victims must be taken to a hospital emergency room. ALWAYS bring the prescription bottle or container.
Special Information
Carvedilol should be taken continuously. Do not stop taking it without your doctor’s knowledge, because abrupt withdrawal may cause chest pain, breathing difficulties, increased sweating, and unusually fast or irregular heartbeat. The dose should be gradually reduced over a period of about 2 weeks.
People taking carvedilol may become dizzy or faint when rising quickly from a sitting or lying position. If this happens to you, sit or lie down until you feel better. Carvedilol can also cause drowsiness, lightheadedness, or blurred vision. Be careful when driving or doing any task that requires concentration.
Contact lens wearers are more likely to experience dry eyes with carvedilol.
Swallow extended-release tablets whole; do not crush or break them.
It is best to take carvedilol at the same time each day. If you forget a dose, take it as soon as you remember. If it is within 4 hours of your next dose, skip the dose you forgot and continue with your regular schedule. Do not take a double dose.
Special Populations
Pregnancy/Breast-feeding: Animal studies indicate that carvedilol passes into the fetal bloodstream and may interfere with pregnancy. When this drug is considered crucial by your doctor, its potential benefits must be carefully weighed against its risks.
It is not known if carvedilol passes into human breast milk, though it passes into rat breast milk. Beta-blocking drugs like carvedilol may affect babies’ hearts. Nursing mothers who must take this drug should use infant formula.
Seniors: Seniors are more likely to develop dizziness and may require reduced dosage.