Carvedilol

Use caution with history of severe anaphylaxis to allergens; patients taking beta-blockers may become more sensitive to repeated challenges. Treatment of anaphylaxis (eg, epinephrine) in patients taking beta-blockers may be ineffective or promote undesirable effects.

May occur; reduce dosage if heart rate drops to • Floppy iris syndrome: Intraoperative floppy iris syndrome has been observed in cataract surgery patients who were on or were previously treated with alpha1-blockers; there appears to be no benefit in discontinuing alpha-blocker therapy prior to surgery. Instruct patients to inform ophthalmologist of carvedilol use when considering eye surgery.

Symptomatic hypotension with or without syncope may occur with carvedilol (usually within the first 30 days of therapy); close monitoring of patient is required especially with initial dosing and dosing increases; blood pressure must be lowered at a rate appropriate for the patient's clinical condition. Initiation with a low dose, gradual up-titration, and administration with food may help to decrease the occurrence of hypotension or syncope. Advise patients to avoid driving or other hazardous tasks during initiation of therapy due to the risk of syncope. Disease-related concerns:

Use with caution in patients suspected of having Prinzmetal variant angina.

In general, patients with bronchospastic disease should not receive beta-blockers; if used at all, should be used cautiously with close monitoring.

Use with caution in patients with diabetes mellitus; may potentiate hypoglycemia and/or mask signs and symptoms (eg, sweating, anxiety, tachycardia). In patients with heart failure and diabetes, use of carvedilol may worsen hyperglycemia; may require adjustment of antidiabetic agents.

Heart failure patients may experience a worsening of renal function (rare); risk factors include ischemic heart disease, diffuse vascular disease, underlying renal dysfunction, and/or systolic BP • Hepatic impairment: Use with caution in patients with mild to moderate hepatic impairment; use is contraindicated in patients with severe hepatic impairment.

Use with caution in patients with myasthenia gravis.

May precipitate or aggravate symptoms of arterial insufficiency in patients with PVD; use with caution and monitor for progression of arterial obstruction.

Use with caution; adequate alpha-blockade should be initiated prior to use of any beta-blocker.

Beta-blocker use has been associated with induction or exacerbation of psoriasis, but cause and effect have not been firmly established.

May mask signs of hyperthyroidism (eg, tachycardia). If hyperthyroidism is suspected, carefully manage and monitor; abrupt withdrawal may exacerbate symptoms of hyperthyroidism or precipitate thyroid storm. Concurrent drug therapy issues:

Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information. Special populations:

Bradycardia may be observed more frequently in elderly patients (>65 years of age); dosage reductions may be necessary. Dosage form specific issues:

Some dosage forms may contain polysorbate 80 (also known as Tweens). Hypersensitivity reactions, usually a delayed reaction, have been reported following exposure to pharmaceutical products containing polysorbate 80 in certain individuals (Isaksson, 2002; Lucente 2000; Shelley, 1995). Thrombocytopenia, ascites, pulmonary deterioration, and renal and hepatic failure have been reported in premature neonates after receiving parenteral products containing polysorbate 80 (Alade, 1986; CDC, 1984). See manufacturer’s labeling. Other warnings/precautions:

Beta-blocker therapy should not be withdrawn abruptly (particularly in patients with CAD), but gradually tapered to avoid acute tachycardia, hypertension, and/or ischemia. Severe exacerbation of angina, ventricular arrhythmias, and myocardial infarction (MI) have been reported following abrupt withdrawal of beta-blocker therapy. Temporary and prompt resumption of beta-blocker therapy may be indicated with worsening of angina or acute coronary insufficiency.

Chronic beta-blocker therapy should not be routinely withdrawn prior to major surgery.