Recurrent chest pain
Agents with β-blocking activity (non-selective ) may produce chest pain
in patients with recurrent chest pain (Prinzmetal’s variant angina
). Caution should be used when Carvedilol is taken by patients doubted of having recurrent chest pain.
Risk of an allergic reaction
Patients with a history of severe allergic reaction to a variety of allergens are at an increased risk while using this medicine. These patients may be unresponsive to the normal doses of epinephrine used to manage an allergic reaction.
Flaccid iris (intraoperative floppy iris syndrome
) has been seen during cataract surgery
in patients treated with Carvedilol. Stopping alpha-1
blocker treatment including Carvedilol before cataract surgery is not beneficial.
Tumor of the adrenal gland (pheochromocytoma)
Patients suspected of having a tumor
of the adrenal gland are at an increased risk when using this medicine. Proper care should be taken when using Carvedilol in patients suspected of having adrenal gland tumor.
Levels of sugar in type-2 diabetes
Patients with diabetes
mellitus and heart failure are at an increased risk when using this medicine. β-blockers may mask the symptoms of low blood pressure, particularly of abnormal heart rhythms. Close monitoring of diabetic patients is required by measuring regular blood glucose measurements, especially during dose titration. Dose adjustment of antidiabetic medicines is also required in diabetic patients using Carvedilol.
Reduced blood flow to the limbs
β-blockers including Carvedilol can increase symptoms of stoppage of blood flow through the arteries in patients with reduced blood flow to the limbs. Caution should be taken in patients with reduced blood flow to the limbs (peripheral vascular disease).
Worsening of the functioning of kidneys
Patients with low blood pressure, recurring chest pain
, and diffuse vascular disease, or kidney insufficiency are at an increased risk while using this medicine. Use of Carvedilol in patients with heart failure has resulted in worsening of the functioning of kidneys. Patients with these risk factors are recommended to discontinue the use of Carvedilol or to reduce the dose during the worsening of the functioning of the kidney.
Major surgical procedures
The reduced ability of the heart to respond to spontaneous adrenergic stimuli may increase the risks of general anesthesia
and medical procedures. Long-term use of beta-blocking therapy should not be routinely withdrawn before to major surgery
Excessive production of thyroid hormone
β- blockers may hide clinical signs of an overactive thyroid, such as increased heartbeat. Sudden withdrawal of β-blockers should be followed in case of worsening of the symptoms of overactive thyroid (thyroid storm).
Discontinuation of therapy
Patients with blockage of the coronary artery are at an increased risk while using this medicine. Severe worsening of angina
and the occurrence of heart attack and irregular heartbeat have been seen in angina patients following the sudden discontinuation of treatment with β-blockers. Discontinue the use of Carvedilol over 1-2 weeks. If chest pain
worsens or blockage of blood flow to the heart develops, use of Carvedilol must immediately begin again, at least temporarily. Patients are advised to limit their physical activities. During the worsening condition of angina, it is recommended to reinstitute the Carvedilol.
Decreased heart rate
Patients with high blood pressure, heart failure, and heart attack are at an increased risk while using this medicine. Carvedilol caused decreased heart rate in about 2% of high blood pressure patients, 9% of heart failure patients, and 6.5% in patients affected from heart attack. The dose should be reduced if pulse rate falls
below 55 beats/minute.
Low blood pressure
Patients with high blood pressure are at an increased risk while using this medicine. Heart failure, severe fall in blood pressure while standing up from a lying or sitting position and temporary loss of consciousness occurred in patients receiving Carvedilol. The chances of these events were higher during the first 30 days of dosing and was a reason for discontinuation of therapy. While starting of therapy, the patients are advised to avoid situations such as driving or hazardous tasks, where injury leads to the condition of fainting
Heart failure/fluid retention
Use of Carvedilol may lead to the worsening condition of heart failure, or fluid retention. If such events occur, it is advised to lower the dose of Carvedilol or temporarily discontinue it.
Patients with bronchospastic diseases (inflammation of the lining of bronchial tubes and damage to the alveoli in the lungs) are at an increased risk while using beta blockers. Carvedilol may be used with caution, in patients who cannot tolerate or do not respond to other antihypertensive agents. The dosing recommendations should be accompanied closely and the dose should be lowered if any sign of reversible reflex contraction
of the smooth muscle in the bronchi is recognized.