Carvedilol Phosphate (2 brand names, 1 dosage form, 1 route)
Available dosage forms: CAPSULE, EXTENDED RELEASE.
Routes of administration: ORAL.
Brand Names
- CARVEDILOL PHOSPHATE
- COREG CR
Dosage and Administration
Carvedilol phosphate extended-release capsules are intended for once-daily administration. Patients controlled with immediate-release carvedilol tablets alone or in combination with other medications may be switched to carvedilol phosphate extended-release capsules based on the total daily doses shown in Table 1. Table 1. Dosing Conversion Daily Dose of Immediate-Release Carvedilol Tablets Daily Dose of Carvedilol Phosphate Extended-Release Capsules When switching from carvedilol 12.5 mg or 25 mg twice daily, a starting dose of carvedilol phosphate extended-release capsules 20 mg or 40 mg once daily, respectively, may be warranted for elderly patients or those at increased risk of hypotension, dizziness, or syncope. Subsequent titration to higher doses should, as appropriate, be made after an interval of at least 2 weeks. 6.25 mg (3.125 mg twice daily) 10 mg once daily 12.5 mg (6.25 mg twice daily) 20 mg once daily 25 mg (12.5 mg twice daily) 40 mg once daily 50 mg (25 mg twice daily) 80 mg once daily Carvedilol phosphate extended-release capsules should be taken once daily in the morning with food. Carvedilol phosphate extended-release capsules should be swallowed whole. Carvedilol phosphate extended-release capsules and/or their contents should not be crushed, chewed, or taken in divided doses.
Contraindications
Carvedilol phosphate extended-release capsules are contraindicated in the following conditions: Bronchial asthma or related bronchospastic conditions. Deaths from status asthmaticus have been reported following single doses of immediate-release carvedilol. Second- or third-degree AV block. Sick sinus syndrome. Severe bradycardia (unless a permanent pacemaker is in place). Patients with cardiogenic shock or who have decompensated heart failure requiring the use of intravenous inotropic therapy. Such patients should first be weaned from intravenous therapy before initiating carvedilol phosphate extended-release capsules. Patients with severe hepatic impairment. Patients with a history of a serious hypersensitivity reaction (e.g., Stevens-Johnson syndrome, anaphylactic reaction, angioedema) to carvedilol or any of the components of carvedilol phosphate extended-release capsules.
Warnings and Precautions
In clinical trials of carvedilol phosphate extended-release capsules in subjects with hypertension (338 subjects) and in subjects with left ventricular dysfunction following a myocardial infarction or heart failure (187 subjects), the profile of adverse events observed with carvedilol phosphate was generally similar to that observed with the administration of immediate-release carvedilol. Therefore, the information included within this section is based on data from controlled clinical trials with carvedilol phosphate extended-release capsules as well as immediate-release carvedilol tablets. This product contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions (including bronchial asthma) in certain susceptible persons. Although the overall incidence of FD&C Yellow No. 5 (tartrazine) sensitivity in the general population is low, it is frequently seen in patients who also have aspirin hypersensitivity.
Mechanism of Action
Carvedilol is a racemic mixture in which nonselective beta-adrenoreceptor blocking activity is present in the S(–) enantiomer and alpha 1-adrenergic blocking activity is present in both R(+) and S(–) enantiomers at equal potency. Carvedilol has no intrinsic sympathomimetic activity.
Overdosage
Overdosage may cause severe hypotension, bradycardia, cardiac insufficiency, cardiogenic shock, and cardiac arrest. Respiratory problems, bronchospasms, vomiting, lapses of consciousness, and generalized seizures may also occur. The patient should be placed in a supine position and, where necessary, kept under observation and treated under intensive-care conditions. The following agents may be administered: For excessive bradycardia:Atropine, 2 mg IV. To support cardiovascular function:Glucagon, 5 to 10 mg IV rapidly over 30 seconds, followed by a continuous infusion of 5 mg/hour; sympathomimetics (dobutamine, isoprenaline, adrenaline) at doses according to body weight and effect. If peripheral vasodilation dominates, it may be necessary to administer adrenaline or noradrenaline with continuous monitoring of circulatory conditions. For therapy-resistant bradycardia, pacemaker therapy should be performed. For bronchospasm, beta-sympathomimetics (as aerosol or IV) or aminophylline IV should be given. In the event of seizures, slow IV injection of diazepam or clonazepam is recommended. NOTE: In the event of severe intoxication where there are symptoms of shock, treatment with antidotes must be continued for a sufficiently long period of time consistent with the 7- to 10-hour half-life of carvedilol. There is no experience of overdosage with carvedilol phosphate extended-release capsules. Cases of overdosage with carvedilol alone or in combination with other drugs have been reported. Quantities ingested in some cases exceeded 1,000 milligrams. Symptoms experienced included low blood pressure and heart rate. Standard supportive treatment was provided and individuals recovered.