Coreg CR (carvedilol phosphate) has has received approval from the FDA. The extended-release capsules are indicated for the treatment of 3 cardiovascular conditions in adults: hypertension, left ventricular (LV) dysfunction after myocardial infarction (MI), and heart failure.1
Although immediate-release carvedilol already is marketed for the same indications as Coreg CR, its twice-daily administration may be inconvenient for some patients. Coreg CR is promoted to improve patient adherence and to offer a simplified treatment regimen through its once-daily dosing. Coreg CR's once-daily administration is due to Flamel's unique Micropump technology.1
Carvedilol exerts its cardiovascular effects through nonselective ?-adrenoreceptor blocking activity and a1-adrenergic blocking activity.2
The Carvedilol or Metoprolol European Trial study evaluated more than 3000 patients with heart failure, comparing the use of carvedilol with the use of metoprolol. The carvedilol group was found to live 1.4 years longer than the metoprolol group.
The Carvedilol Post-Infarct Survival Control in Left Ventricular Dysfunction trial studied carvedilol against placebo in 1959 patients with a recent MI and an LV ejection fraction of =40%. Mortality was found to be reduced by 23% in the carvedilol group.
The use of carvedilol in hypertension with concomitant diabetes was evaluated in a trial called Comparing the Glycemic Effects of Carvedilol and Metoprolol in High Blood Pressure Patients with Diabetes. The double-blind trial studied carvedilol in addition to an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker in well-controlled type 2 diabetic patients with mild-to-moderate hypertension. The study found that carvedilol lowered blood pressure without affecting blood glucose levels, lipids, or weight gain.1,2
Coreg CR is contraindicated in patients with a history of hypersensitivity to carvedilol or its components, bronchial asthma or related conditions, second-or third-degree atrioventricular block, sick sinus syndrome, severe bradycardia without a pacemaker, or cardiogenic shock, or in decompensated patients using intravenous inotropic treatment.
Patients with severe hepatic impairment also should not use Coreg CR. Patients with coronary artery disease who are using Coreg CR should be warned against sudden discontinuation of treatment, which may result in a severe angina exacerbation, MI, or ventricular arrhythmia. Discontinuation of Coreg CR, if appropriate, should occur over 1 to 2 weeks and under the supervision of a health care provider.
Coreg CR should be used cautiously in patients with peripheral vascular disease, diabetes, hyperthyroidism, or nonallergic bronchospasm or in patients undergoing anesthesia or major surgery.2
The dose of Coreg CR is highly individualized and often requires careful titration for the treatment of heart failure, LV dysfunction following MI, or hypertension.
Patients already using immediate-release carvedilol may be converted to Coreg CR based on the following scale:
?3.125 mg 2?/day (6.25 mg total) converts to 10 mg 1?/day Coreg CR
?6.25 mg 2?/day (12.5 mg total) converts to 20 mg 1?/day Coreg CR
?12.5 mg 2?/day (25 mg total) converts to 40 mg 1?/day Coreg CR
?25 mg 2?/day (50 mg total) converts to 80 mg 1?/day Coreg CR2
Coreg CR always should be taken with food and never within 2 hours of alcohol.
Pharmacists should advise patients using the medication to contact their doctor if signs of worsening heart failure occur, such as weight gain or shortness of breath. Patients should use caution on standing, because dizziness or fainting may occur. If these conditions occur and they are bothersome, they should be reported to a physician.
As a class,?-blockers may mask signs of hypoglycemia and may potentiate the hypoglycemic effect of insulin. Any changes in blood glucose levels should be reported to a physician.
Side effects of Coreg CR may include shortness of breath, decreased heart rate, weight gain, fatigue, hypotension, dizziness, or fainting.1,2 Patients using contact lenses may notice decreased lacrimation. Patients, however, never should discontinue Coreg CR treatment without a physician's advice.
Dr. Holmberg is a pharmacist with Phoenix Children's Hospital, Phoenix, Ariz.
1. FDA approves new, once-a-day Coreg CR for the treatment of three key cardiovascular conditions. Available at: http://us.gsk.com/news/archive.htm. Accessed January 2007.
2. Coreg CR Complete Prescribing Information. Available at: http://us.gsk.com/products/assets/us_coregcr.pdf. Accessed January 2007.