Drug Detail:Carvedilol (Carvedilol [ kar-ve-dil-ole ])
Drug Class: Non-cardioselective beta blockers
1. How it works
- Carvedilol is a heart medication that works on alpha and beta receptors present in blood vessels and muscles.
- Carvedilol has a 'non-selective' action - this means that it not only affects beta receptors in the heart, it also affects beta receptors in the lungs (this may cause breathing difficulties in people with preexisting lung disease). Carvedilol's alpha-blocking activity means it helps to dilate (keep open) blood vessels around the heart.
- Carvedilol belongs to the class of medicines known as beta-blockers/alpha-1 blockers.
2. Upsides
- Used for the treatment of high blood pressure (hypertension). May be used alone or in combination with other medicines for high blood pressure.
- Can be used to treat mild-to-severe heart failure, usually in addition to other agents, to increase the chance of survival and decrease the risk of hospitalization.
- May be used following a heart attack (myocardial infarction) in people with a poor left ventricular ejection fraction of 40% or less.
- Generic carvedilol is available.
3. Downsides
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- Treatment initiation may be associated with transient symptoms of dizziness and lightheadedness within the first hour after dosing, due to a lowering of blood pressure. Avoid driving or operating machinery during this time if affected.
- May cause fluid retention, which may be relieved by diuretics prescribed by a doctor.
- May aggravate peripheral circulatory disorders, cause several unwanted heart-related effects, and may affect breathing, so the response must be monitored.
- May cause tiredness, dizziness, diarrhea, nausea, weight gain, and laboratory abnormalities. If the heart rate drops below 55 beats per minute, the dosage of carvedilol should be reduced.
- Generally not recommended for people with asthma or other types of bronchospastic disease; deaths related to breathing difficulties have been reported following single doses of carvedilol tablets. Also not suitable for people with certain heart conditions, thyroid disease, or severe liver disease.
- Abrupt discontinuation may precipitate an exacerbation of angina or more severe heart conditions (eg, heart attack) in people with coronary artery disease. Discontinue only under a doctor's advice over a minimum of one to two weeks.
- May also cause worsening of heart failure during up-titration or impair renal function in people with heart failure.
- Can mask symptoms of hypoglycemia in people with diabetes. Can also cause hyperglycemia in heart failure patients with diabetes. Blood glucose levels should be monitored when carvedilol is initiated, adjusted, or discontinued.
- May interact with some drugs including cyclosporine, digoxin, amiodarone, insulin, other drugs used for heart disease, and some anesthetics.
- Not approved for children under the age of 18.
- Should only be used during pregnancy if the benefits outweigh the risks. Animal studies have not revealed any adverse developmental outcomes, there are no controlled data in humans. If used during pregnancy, carvedilol should be stopped 2 to 3 days before the expected birth; if this is not possible then the newborn should be monitored for the first 2 to 3 days of life. The use of beta-blockers during the third trimester of pregnancy may increase the risk of hypotension, bradycardia, hypoglycemia, and respiratory depression in the neonate. Excreted into breast milk but considered to present a low risk to the breastfed infant, but no published data exist. Other agents may be preferred, especially while nursing a newborn or preterm infant.
Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects
4. Tips
- Take with food to reduce the risk of orthostatic hypotension (low blood pressure on standing).
- The dosage needs to be individualized and it may take some time to establish the correct dosage.
- Seek medical advice if you notice your heart rate has significantly slowed.
- Do not discontinue carvedilol without talking to your doctor.
- Tell your doctor if you experience shortness of breath or weight gain when taking Carvedilol.
- Get up slowly from a sitting or lying down position to standing as carvedilol may cause a sudden drop in blood pressure.
- Avoid driving or operating machinery if carvedilol makes you dizzy or tired.
- Report any changes in blood sugar levels to your doctor if you have diabetes.
- Contact lens wearers may notice carvedilol decreases the natural lubrication of the eye; lubricant eye drops may be needed.
- Dosage adjustment may be needed carvedilol makes you feel dizzy or faint; seek medical advice. Do not drive or operate machinery if you feel dizzy from carvedilol tablets. Alcohol may enhance these side effects, so is best avoided.
- Talk to your doctor if you are pregnant, intending to become pregnant, or breastfeeding because carvedilol may not be suitable for you.
5. Response and effectiveness
- Effects of carvedilol (blood pressure lowering, reduction in exercise-induced heart rate) are usually seen within 30-60 minutes of administration. Blood pressure is usually noticeably lower in the standing rather than the sitting or lying down position.
6. Interactions
Medicines that interact with carvedilol may either decrease its effect, affect how long it works for, increase side effects, or have less of an effect when taken with carvedilol. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.
Common medications that may interact with carvedilol include:
- Antidepressants, such as fluoxetine, paroxetine, St John’s Wort, and monoamine oxidase inhibitors
- Antifungals, such as fluconazole
- Antihistamines, such as diphenhydramine
- Bupropion, which may be used for the treatment of depression and as a stop-smoking aid
- Antimalaria agents, such as hydroxychloroquine
- Fingolimod, which may be used for the treatment of multiple sclerosis
- HIV medications such as ritonavir or delavirdine
- Indigestion and heartburn medications, such as cimetidine and ranitidine
- Some medications used to treat mental illness, such as haloperidol or thioridazine
- Some heart medications, such as amiodarone, clonidine, digoxin, diltiazem, propafenone, quinidine, and verapamil
- Other medications including celecoxib, hydralazine, and rifampicin
- NSAIDs, such as diclofenac, ibuprofen, and indomethacin, may decrease the blood pressure-lowering capabilities of carvedilol.
People taking oral medications for diabetes may need to talk to their doctor about adjusting the dose of their medicine.
Note that this list is not all-inclusive and includes only common medications that may interact with carvedilol. You should refer to the prescribing information for carvedilol for a complete list of interactions.