Carvedilol belongs to the class of medications called beta-blockers. Carvedilol is used to treat congestive heart failure (CHF), including severe heart failure. It is often taken with a diuretic (water pill) and an angiotensin converting enzyme (ACE) inhibitor.

CHF occurs when the heart is unable to pump efficiently enough to supply adequate amounts of oxygen-rich blood to different areas of the body. Carvedilol helps this situation by relaxing blood vessels, reducing the need for oxygen in the body, and by helping the heart beat more regularly and efficiently.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The usual recommended starting dose for this medication is 3.125 mg 2 times daily in order to allow the body to get used to it. Your doctor will then increase the dose every 2 weeks until the most effective dose is reached.

Carvedilol should be taken with food at approximately the same times every day.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to use this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take 2 doses within 6 hours of one another. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice. If you miss more than 2 doses in a row, contact your doctor for instructions on restarting the medication.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not take carvedilol if you:

• are allergic to carvedilol or to any of the ingredients of the medication
• have a certain type of heart valve disease
• have a type of heart failure known as decompensated heart failure
• have a very slow heart rate
• have bronchial asthma or certain other breathing conditions
• have cardiogenic shock
• have certain types of heart rhythm problems
• have certain types of liver disease
• have mental incapacity, unless closely supervised by an appropriate caregiver
• have serious heart block (second- or third-degree AV block)
• have an irregular heart rhythm that requires intravenous medication to support the heartbeat
• have very low blood pressure

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• back pain
• constipation
• diarrhea
• dizziness
• drowsiness
• headache
• heartburn
• impotence
• low blood pressure, causing dizziness or fainting when rising from a sitting or laying position
• nausea
• rash
• slow heartbeat
• trouble sleeping
• vomiting
• weakness
• weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blurred vision
• breathing problems (e.g., shortness of breath, cough, wheezing, nasal congestion, runny nose)
• chest pain
• generalized swelling or swelling of feet, ankles, or lower legs
• tenderness on upper right side of body

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (i.e., swelling of face or throat, hives, or difficulty breathing)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Circulation problems: This medication can cause blood vessels in the extremities to become narrowed. The smaller blood vessels may narrow enough that blood cannot flow through easily, causing discoloration and numbness in the areas beyond where the blood vessel closes off. If you notice coldness, waxiness, or numbness in the fingers and toes, with or without pain, contact your doctor as soon as possible.

Diabetes: Carvedilol may hide the symptoms of low blood sugar, such as shakiness or rapid heart beat. It can also cause the blood sugar to drop, making it more difficult for people with diabetes to control their blood sugar. If you have diabetes or low blood sugar, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Dizziness/fainting: Dizziness and fainting are side effects of carvedilol and may occur after first starting this medication. Do not drive a car or do anything that requires alertness until you know how this medication affects you.

Heart failure: Beta-blockers like carvedilol can worsen existing heart failure. It is important to take carvedilol exactly as prescribed by your doctor to decrease the chance of this happening.

Kidney function: Rarely, carvedilol can cause decreased kidney function and kidney failure. If you have reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause this medication to build up in the body, causing side effects. It may also cause decreased liver function. If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Low blood pressure: Occasionally, blood pressure drops too low after taking this medication. This usually happens after the first or second dose or when the dose is increased. To reduce the risk of dizziness, get up slowly from a lying or sitting position. If low blood pressure causes you to faint or feel lightheaded, contact your doctor.

Prinzmetal's angina: Carvedilol may increase the number and duration of angina attacks in patients with Prinzmetal's angina. People who have this condition should be cautious while taking carvedilol.

Primary regurgitative valvular heart disease: The safety and effectiveness of carvedilol have not been well studied for use by people with this condition. People who have this condition should be cautious while taking carvedilol.

Severe allergies: People with allergies severe enough to cause anaphylaxis (a severe allergic reaction where swelling of the face, lips, and throat make it difficult to breathe) should talk to their doctor about what to do if they have an allergic reaction. Carvedilol may make it more difficult to treat their allergic reaction with epinephrine.

Stopping the medication: People with heart disease who stop taking this medication abruptly may experience severe effects, such as chest pain, irregular heartbeat, or heart attack. If you have heart disease, do not stop taking this medication without checking with your doctor first. When this medication needs to be stopped, it should be done gradually under supervision of your doctor.

Surgery: This medication interferes with how certain medications used during surgery work in the body. If you are scheduled for surgery, make sure that everyone involved in your care knows about all the medications you use.

Thyroid: Carvedilol can mask the symptoms of too much thyroid hormone in the body, such as a rapid heartbeat or tremor. If you have a thyroid condition, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Pregnancy: The medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

Seniors: Seniors are more likely to experience side effects from this medication.

There may be an interaction between carvedilol and any of the following:

• abiraterone acetate
• aldesleukin
• aliskiren
• alpha agonists (e.g., clonidine, methyldopa)
• alpha blockers (e.g., alfuzosin, doxazosin, prazosin, silodosin, tamsulosin)
• amiodarone
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• angiotensin-converting enzyme inhibitors (ACEIs; captopril, enalapril, ramipril)
• angiotensin receptor blockers (ARBs; e.g., candesartan, irbesartan, losartan)
• anti-cancer medications (e.g., brentuximab, doxorubicin, etoposide, paclitaxel, topotecan, vincristine)
• anti-psychotics (e.g., cariprazine, chlorpromazine, clozapine, haloperidol, olanzepine, paliperidone, quetiapine, risperidone)
• apomorphine
• barbiturates (e.g., butalbital, phenobarbital)
• beta-2 agonists (e.g., formoterol, salmeterol, salbutamol)
• beta-adrenergic blockers (e.g., atenolol, propranolol, sotalol)
• brimonidine
• bromocriptine
• bupropion
• calcium channel blocking agents (e.g., diltiazem, nifedipine, verapamil)
• cannabis
• celecoxib
• colchicine
• conivaptan
• cyclosporine
• dabigatran
• darifenacin
• dexmethylphenidate
• diabetes medications (e.g., acarbose, canagliflozin, glyburide, insulin, lixisenatide, metformin, rosiglitazone, sitagliptin)
• digoxin
• dipyridamole
• disopyramide
• diuretics (water pills; e.g., furosemide, hydrochlorothiazide, triamterene)
• donepezil
• dronedarone
• edoxaban
• epinephrine
• ergot products (e.g., ergotamine, ergonovine)
• fentanyl
• flecainide
• galantamine
• grapefruit juice
• grass pollen extract
• guanfacine
• certain HIV protease inhibitors (e.g., darunavir, indinavir, ritonavir, saquinavir, tipranavir)
• levodopa
• lidocaine
• mefloquine
• methylphenidate
• mifepristone
• mirabegron
• minoxidil
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• morphine
• nabilone
• naloxegol
• nitrates (e.g., nitroglycerin, isosorbide dinitrate, isosorbide mononitrate)
• non-steroidal anti-inflammatory medications (NSAIDs; e.g., diclofenac, ibuprofen, ketorolac, naproxen)
• pentoxifylline
• phenytoin
• phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil, vardenafil)
• pilocarpine
• pramipexole
• primidone
• certain protein kinase inhibitors (e.g., bosutinib, ceritinib, crizotinib, imatinib, lapatinib, nilotinib, pazopanib, tofacitinib)
• quinidine
• rifampin
• riociguat
• rivastigmine
• romidepsin
• ropinirole
• rotigotine
• sacubitril
• selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, paroxetine, sertraline)
• sirolimus
• somatostatin analogues (e.g., lanreotide, octreotide, pasireotide)
• sphingosine 1-phosphate receptor (S1P) receptor inhibitors (e.g., fingolimod, ponesimod, siponimod)
• tacrolimus
• terbinafine
• theophyllines (e.g., aminophylline, oxtriphylline, theophylline)
• tizanidine
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, nortriptyline)
• tretinoin
• yohimbine

If you are taking any of these, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.