nts with bronchospastic disease (e.g., chronic bronchitis, emphysema) should, in general, not receive β‑blockers. COREG CR may be used with caution, however, in patients who do not respond to, or cannot tolerate, other antihypertensive agents. It is prudent, if COREG CR is used, to use the smallest effective dose, so that inhibition of endogenous or exogenous β‑agonists is minimized.
In clinical trials of subjects with heart failure, subjects with bronchospastic disease were enrolled if they did not require oral or inhaled medication to treat their bronchospastic disease. In such patients, it is recommended that COREG CR be used with caution. The dosing recommendations should be followed closely and the dose should be lowered if any evidence of bronchospasm is observed during up‑titration.
5.6 Glycemic Control in Type 2 Diabetes
In general, β‑blockers may mask some of the manifestations of hypoglycemia, particularly tachycardia. Nonselective β‑blockers may potentiate insulin‑induced hypoglycemia and delay recovery of serum glucose levels. Patients subject to spontaneous hypoglycemia or diabetic patients receiving insulin or oral hypoglycemic agents should be cautioned about these possibilities.
In patients with heart failure and diabetes, carvedilol therapy may lead to worsening hyperglycemia, which responds to intensification of hypoglycemic therapy. It is recommended that blood glucose be monitored when dosing with COREG CR is initiated, adjusted, or discontinued. Trials designed to examine the effects of carvedilol on glycemic control in patients with diabetes and heart failure have not been conducted.
In a trial designed to examine the effects of immediate‑release carvedilol on glycemic control in a population with mild‑to‑moderate hypertension and well-controlled type 2 diabetes mellitus, carvedilol had no adverse effect on glycemic control, based on HbA1c measurements [see Clinical Studies (14.4)].
5.7 Peripheral Vascular Disease
β‑blockers can precipitate or aggravate symptoms of arterial insufficiency in patients with peripheral vascular disease. Caution should be exercised in such individuals.
5.8 Deterioration of Renal Function
Rarely, use of carvedilol in patients with heart failure has resulted in deterioration of renal function. Patients at risk appear to be those with low blood pressure (systolic blood pressure less than 100 mm Hg), ischemic heart disease and diffuse vascular disease, and/or underlying renal insufficiency. Renal function has returned to baseline when carvedilol was stopped. In patients with these risk factors it is recommended that renal function be monitored during up‑titration of COREG CR and the drug discontinued or dosage reduced if worsening of renal function occurs.
5.9 Major Surgery
Chronically administered β-blocking therapy should not be routinely withdrawn prior to major surgery; however, the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures.
5.10 Thyrotoxicosis
β‑adrenergic blockade may mask clinical signs of hyperthyroidism, such as tachycardia. Abrupt withdrawal of β‑blockade may be followed by an exacerbation of the symptoms of hyperthyroidism or may precipitate thyroid storm.
5.11 Pheochromocytoma
In patients with pheoc |
