Coreg or Coreg CR: Carvedilol

What is carvedilol?

Doctors prescribe carvedilol to people who have hypertension (high blood pressure). Carvedilol also prevents episodes of stroke, heart attack, and heart failure. 

Carvedilol belongs to a class of drugs called beta-adrenergic blocking agents, also known as beta-blocking agents, or more commonly, beta-blockers. Beta-blockers work by affecting the response of nerves to certain stimuli. As a result, this prescription drug helps lower the heart's workload by reducing the demand for blood and oxygen. Carvedilol also relaxes blood vessels by blocking alpha receptors, lowering blood pressure. It also slows the heart rate by blocking the action of certain hormones, like adrenaline.

Carvedilol is the generic drug name for the brand Coreg or Coreg CR (Extended-Release).

What does carvedilol treat?

Doctors prescribe carvedilol to people at risk for or with a history of:

• Hypertension 

• Heart disease

• Heart attacks

• Stroke 

In addition, carvedilol is prescribed with other drugs to treat heart failure or prevent chest pain due to angina (reduced blood flow to the heart). Doctors may also prescribe carvedilol to those with atrial fibrillation (a-fib), which is a certain type of irregular heartbeat.

How do you take carvedilol?

Your doctor will prescribe carvedilol based on your individual needs. They may increase or decrease the dosage as needed. Always speak with your doctor before making any changes to your medication regimen.

 Carvedilol is available in the following dosages and forms:

• Tablet (3.125mg, 6.25mg, 12.5mg, 25mg)

• Extended-ReleaseCapsule (10mg, 20mg, 40mg, 80 mg)

For hypertension

Immediate-Release

• An initial dose of 6.25 mg, taken orally, twice daily

• After seven to 14 days, it could be increased, as tolerated, to 12.5mg, twice daily, then 25mg, twice daily 

Extended-Release

• An initial dose of 20mg, taken orally, once daily for one to two weeks

• The subsequent dose could be increased to 40mg, once daily, as needed

• Dosage should not exceed more than 80mg per day

For congestive heart failure

Immediate-Release

• An initial dose of 3.125mg, taken orally every 12 hours for two weeks

• The subsequent dose could be increased every two weeks, as tolerated, to 6.25mg, 12mg, or 25mg, twice daily

• The maximum dosage could be 25mg, taken orally, twice daily

Extended-Release

• An initial dose of 10mg, taken orally, once daily, for one to two weeks

• The subsequent dose could be increased to 20mg per day, 40 mg per day, or 80 mg per day, as needed

For left ventricular dysfunction (LVD) following a heart attack

Immediate-Release

• An initial dose of 3.125mg to 6.25mg, taken orally every 12 hours

• After 3–10 days, it could be increased as tolerated, first to 12.5mg every 12 hours, and then to 25mg every 12 hours

Extended-Release

• An initial dose of 10–20 mg, taken orally, once, daily

• It could be increased every 3-10 days, as tolerated, up to 80mg daily

For angina pectoris

Immediate-Release

• 25–50mg, taken orally, twice daily

Seeing results of carvedilol

Carvedilol typically starts to work within two hours of taking it.

If you are using carvedilol to treat hypertension, it usually takes about seven days to get results. You may not notice a difference at first, but that doesn’t mean the medication isn’t working.

Potential side effects of carvedilol

Common side effects of carvedilol include:

• Weakness

• Dizziness

• Tiredness

• Dry eyes

• Weight gain

• Low blood pressure or hypotension

• Hyperglycemia (high blood sugar)

• Slow heart rate

• Nausea

• Cough

• Headache

• Vomiting

• Indigestion

• Lightheadedness

• Runny nose

 Rare side effects of carvedilol include:

• Raynaud’s phenomenon (reduced blood flow to fingers)

• Impotence

• Depression

• Insomnia

• Skin rash

• Bronchospasm (tightening of the airways)

• Severe allergic reaction

Long-term use of carvedilol

Doctors prescribe carvedilol for both short-term and long-term use. Those who take carvedilol for health maintenance may need to take it for life.

Missed doses

If you miss a dose of carvedilol, take it as soon as you remember. However, do not take it within six hours of your next scheduled dose. If you are too close to the timing of the next dose, skip it and take the next dose as planned. Try to take your medication on a regular schedule and avoid missed doses.

Overdoses

If you accidentally take too much carvedilol, you might experience the following side effects:

• Low blood pressure

• Slow heart rate

• Vomiting

• Fainting

• Seizures

• Heart attack

• Trouble breathing

If you know or suspect that you have exceeded your prescribed amount of carvedilol, call 911 or seek immediate medical attention.

What to discuss with your doctor before taking carvedilol

 Here are some of the topics to discuss with your doctor before taking carvedilol:

• Allergies you have or past allergic reactions to medications (especially carvedilol or other beta-blockers). 

• Medications you are currently taking (prescribed or non-prescribed), including vitamins and supplements you take (or plan to take).

• Existing health conditions, like diabetes, hyperthyroidism, liver disease, asthma, Prinzmetal’s angina, or pheochromocytoma.

• Circulatory (blood flow) problems in your legs and feet. 

• Whether you are pregnant or trying to get pregnant. 

• Whether you are currently breastfeeding or planning to breastfeed. 

• Upcoming medical or dental procedures (or plans to have one). 

• Whether or not you consume alcohol, how much, and how frequently.

• Your career, lifestyle, and hobbies. Some side effects of carvedilol may prevent you from certain activities, such as driving. 

• Suitability of wearing contact lenses (dry eyes are a side effect of taking carvedilol). 

• Appropriate dietary and exercise regimens that are suitable while using carvedilol to treat hypertension (if applicable).

Stopping carvedilol

Always speak with your doctor before stopping carvedilol. Suddenly stopping carvedilol can cause serious issues, including severe chest pain, high blood pressure, irregular heartbeat, or heart attack.

 If your doctor determines that it’s appropriate to take you off of carvedilol, they will monitor you closely for several weeks. You will likely be advised to slowly wean down the dose rather than stop this medication abruptly unless you are having severe side effects.

Carvedilol and pregnancy

There is insufficient data on the safety of carvedilol’s use in pregnant women or the risks it may pose to unborn children.

Be sure to speak with your doctor about carvedilol’s suitability if you are pregnant or planning on becoming pregnant. If you are taking carvedilol while pregnant, your doctor will likely advise you to stop taking it at least two or three days before the expected birth. Carvedilol can pass from mother to child through breastfeeding.

Carvedilol falls into what was previously called Category C, meaning that risk to the fetus is possible.¹ The risks vs. benefits of carvedilol use during pregnancy should be discussed directly with your physician, who will determine if you should continue this medication. Typically, carvedilol should not be stopped abruptly. More commonly, it is weaned down slowly with decreasing doses over one to two weeks. You should follow the instructions given to you by your physician which are specific to your particular medical profile.

Carvedilol and interactions with other drugs

Drugs that may interact with carvedilol and cause unwanted side effects include:

• Beta-blockers Acebutolol (Sectral), atenolol (Tenormin), bisoprolol (Concor), metoprolol (Lopressor), and propranolol (Inderal) should not be used with carvedilol, as it could cause low blood pressure or reduced heart rate.

• Diabetes medication When taken with carvedilol, insulin injections and oral medication for diabetes may increase the risk of low blood sugar levels.

• Cyclosporine Taking carvedilol with the organ transplant rejection drug cyclosporine (Gengraf, Neoral, or Sandimmune) could increase your level of cyclosporine.

• Clonidine Taking carvedilol with the blood pressure medication clonidine (Catapres) could significantly lower your blood pressure and heart rate.

Carvedilol allergy information

Severe allergic reaction, also known as anaphylaxis is rare, but a possibility for those who take carvedilol. Symptoms of anaphylaxis include:

• Lightheadedness

• Difficulty breathing 

• Swelling of the face and lips

• Hives

• Wheezing

• Confusion

• Anxiety

• Elevated heart rate

• Clammy skin

If you experience symptoms of a severe allergic reaction, seek immediate medical help or call 911.

Clinical trial history of carvedilol

Carvedilol was developed to treat congestive heart failure. It has gone through four clinical trials in the US, and one in Australia/New Zealand. Carvedilol received FDA approval in 1995.

Tips and advice for taking carvedilol:

• Take carvedilol at the same time every day.

• Always take carvedilol with food to reduce the risk of a drop in blood pressure from suddenly standing up, sitting, or lying down.

• When sitting up or lying down, do so slowly to avoid dizziness.

• Check your blood pressure at least twice per day, especially when starting to take carvedilol. Inform your doctor if your condition hasn’t improved after a week.

• If you have diabetes, frequently monitor your blood sugar while taking carvedilol.

• Avoid driving, using machinery, or doing activities that require full attention. Carvedilol may cause dizziness.

• Avoid drinking alcohol within two hours before or after taking this drug.

• Never switch from immediate-release to extended-release Carvedilol without guidance and approval from your doctor.

• Follow your doctor’s recommendations for diet and exercise.

• Keep carvedilol away from moisture and heat. Store it at room temperature.