Carvedilol (Coreg): High Blood Pressure Management

  • Type of Drug: Alpha-beta-adrenergic blocker
  • Prescribed for: High blood pressure. Also used for congestive heart failure, angina pains, and cardiomyopathy
  • Brand Name: Coreg

General Information of Carvedilol (Coreg)

Carvedilol blocks both the alpha- and beta-adrenergic portions of the nervous system. This unique combination of actions produces the following effects on the body: It reduces the amount of blood pumped with each heartbeat and also decreases the responsiveness of the heart to various kinds of stimulation that normally cause tachycardia, or very rapid heartbeat. Its beta-blocking effects begin within an hour of taking the first dose of Carvedilol, and maximum blood pressure lowering happens after 1 or 2 weeks. The drug also causes blood vessels to widen, and makes it easier for the heart to pump blood more efficiently. People, with heart failure have traditionally been warned against taking betablocking drugs, but a study reported late in 1995 showed that Carvedilol provided an important benefit for people with heart failure.

Because Carvedilol blocks the alpha-nervous-system receptors, it lowers blood pressure more when you are standing than when you are lying down. This effect leads to a greater chance of dizziness when rising quickly from a sitting or lying position than with other drugs.

Cautions and Warnings

Carvedilol may injure the liver in about 1 of every 100 people who take it Those who already have severe liver disease should not take this medicine. Call your doctor at once if you develop signs of liver damage (severe itching, dark urine, unexplained flu, loss of appetite, yellowing of the eyeballs or skin). Check with your doctor about continuing Carvedilol if you are having general anesthesia. Heart function depressed by anesthetics can be made worse if you are also taking Carvedilol.

Carvedilol can mask the signs of low blood sugar and may increase the effects of Insulin or oral antidiabetes drugs, making it more difficult to recover from low blood sugar.

Carvedilol can also mask the symptoms of an overactive thyroid gland. Abruptly stopping Carvedilol can bring on an attack of hyperthyroidism.

Possible Side Effects

Most Carvedilol 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 difficulty, fatigue, back pain, urinary infection, viral infections, high blood-triglyceride levels, low blood platelet counts.
  • Less common: extra heartbeats, palpitation, blood pressure changes, fainting, reduced blood supply to the arms and legs (aches, cramps, pain or tiredness on walking, or in the foot, thigh, hip, or buttocks), tingling in the hands or feet, reduced feeling, fainting, depression, nervousness, constipation, stomach gas, fiver irritation, cough, male impotence and reduced sex drive, 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, feelings of ill health, sweating, muscle aches.
  • Rare: angina pain, abnormal heart rhythms, heart failure, migraines, neuralgia, confusion, forgetfulness, slight paralysis, asthma, allergy, bronchial spasm, blood in the urine, frequent urination, heir loss, hearing loss, weight gain and sugar in the urine, kidney function loss, potassium level changes.

Drug Interactions of Carvedilol (Coreg)

  • Carvedilol increases the effects of Insulin and oral antidiabetes drugs. People who must take this combination must monitor their blood sugar regularly. Call your doctor if there is any change from your normal pattern.
  • Carvedilol increases the effects of Verapamil, Diltiazem, or similar calcium-channel-blocking drugs.
  • Carvedilol increases the blood-pressure-lowering effect of Clonidine. People taking this combination may need less medicine to control their pressure.
  • Carvedilol increases the amount of Digoxin in the blood by about 15 percent when the drugs are taken together. Digoxin doses may have to be adjusted when you are starting, taking, or stopping Carvedilol.
  • Cimetidine increases the amount of Carvedilol absorbed into the blood by about 30 percent, but it may not affect you.
  • Rifampin increases the breakdown of Carvedilol and reduces the amount of Carvedilol in the blood by about 70 percent. Dosage adjustment is necessary if you must mix these medicines.

Food Interactions

Food slows the rate at which Carvedilol is absorbed into the blood. Take each dose of Carvedilol with food to reduce the risk of dizziness or fainting.

Usual Dose

Adult: Adult: 6.25 mg twice a day to start, increased up to 25 mg twice a day if needed.
Child: not recommended.

Overdosage

Carvedilol overdose may cause very low blood pressure (dizziness, fainting), slow heartbeat, and other heart problems, including shock and heart attack. Breathing problems, bronchial spasm, vomiting, periods of unconsciousness, and seizures may also develop. Three cases of overdose are known (including a 2-year-old); all victims all fully recovered. Overdose victims must be taken to a hospital emergency room for treatment. ALWAYS bring the medicine bottle with you.

Special Information of Carvedilol (Coreg)

Carvedilol is meant to be taken continuously. Do not stop taking it unless directed to do so by your doctor; abrupt withdrawal may cause chest pain, difficulty breathing, 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 and even faint on standing. 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 performing complex tasks.

Contact lens wearers are more likely to experience dry eyes if taking Carvecjilol.

It is best to take your medicine 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 missed dose and continue with your regular schedule. Do not take a double dose of Carvedilol.

Special Populations

Pregnancy/Breast-feeding
Animal studies indicate that Carvedilol passes into the fetal bloodstream and can interfere with a normal pregnancy, but there is no human information available. This drug should be taken during pregnancy only if its possible benefits outweigh its risks.
It is not known if Carvedilol passes into human breast milk, though it passes into rat breast miik. Beta-blocking drugs may affect babies’ hearts. Nursing mothers who must take this drug should bottle-feed their babies.

Seniors
Seniors break down Carvedilol less efficiently than younger adults and may have 50 percent more drug in their blood than younger people. Older adults may be more likely to develop drug side effects, especially dizziness.