GENERIC NAME: carvedilol
BRAND NAME: Coreg
DRUG CLASS AND MECHANISM: Carvedilol is used for treating
high blood pressure and congestive heart failure. It is related to
labetalol (Normodyne, Trandate). Carvedilol blocks receptors of the
adrenergic nervous system, the system of nerves in which epinephrine
(adrenalin) is active. Nerves from the adrenergic system enter the
heart and release an adrenergic chemical (norepinephrine) that
attaches to receptors on the heart's muscle and stimulates the muscle
to beat more rapidly and forcefully. By blocking the receptors,
carvedilol reduces the heart's rate and force of contraction and
thereby reduces the work of the heart. Carvedilol also blocks
adrenergic receptors on arteries and causes the arteries to relax and
the blood pressure to fall. The drop in blood pressure further
reduces the work of the heart since it is easier to pump blood
against a lower pressure. The FDA first approved carvedilol in 1995.
GENERIC AVAILABLE: yes
PRESCRIPTION: yes
PREPARATION: Tablets, 3.125mg, 6.25mg, 12.5mg, and 25mg.
STORAGE: Tablets should be stored at room temperature, 15-
30°C (59-86°F).
PRESCRIBED FOR: Carvedilol is used by itself or with a
diuretic ("water-pill") to control high blood pressure. Carvedilol
also may be used in combination with other drugs to manage mild or
moderate congestive heart failure. When combined with other treatments for heart disease
among patients with recent heart attacks, carvedilol can reduce the risk of a
second heart attack by 40% and increase survival among patients with congestive
heart failure.
DOSING: Carvedilol usually is given twice daily. For high
blood pressure, the dose may range from 6.25mg twice daily to a
maximum of 25mg twice daily. For congestive heart failure, the dose
may range from 3.25mg twice daily to a maximum of 25mg twice daily in
persons weighing less than 85kg (187 pounds) or 50mg twice daily in
persons weighing more than 85kg (187 pounds). Carvedilol should be
taken with food since this increases the amount of absorbed drug that
reaches the heart and arteries. Stopping and changing doses of
carvedilol should be done under the direction of a physician since
sudden changes in dose can result in serious cardiac complications
such as arrhythmias.
DRUG INTERACTIONS: Carvedilol can mask early warning
symptoms of hypoglycemia (low blood sugar) such as tremors and
increased heart rate. (These symptoms are caused by activation of
the adrenergic nervous system which is blocked by the carvedilol.)
Therefore, diabetics taking medications that lower blood sugar such
as insulin or oral anti-diabetic medications may need to increase the
frequency with which they monitor their blood sugar.
Carvedilol taken with calcium channel blockers such as diltiazem (Cardizem) or verapamil
(Calan) may trigger an irregular heart rhythm
or an increase in blood pressure.
Reserpine, monoamine oxidase inhibitors (phenelzine or isocarboxazid)
and clonidine (Catapres), because they have similar mechanisms of
action as carvedilol, may greatly accentuate the effects of
carvedilol and cause a steep decline in blood pressure and/or heart
rate. Close monitoring of blood pressure and heart rate may be
needed.
Carvedilol may cause an increase in digoxin (Lanoxin) blood levels.
Therefore, in patients receiving digoxin, the digoxin blood level
should be monitored if carvedilol is started, adjusted or
discontinued.
Rifampin (Rifadin) can sharply decrease the carvedilol blood level.
Therefore, in patients taking rifampin, the dose of carvedilol may
need to be increased.
Carvedilol shares a common pathway for elimination by the liver with
several other drugs such as quinidine (Quinaglute), fluoxetine (Prozac), paroxetine
(Paxil), or propafenone (Rythmol). Use of these
drugs may block the elimination of carvedilol. No studies have been
done to confirm these effects on the elimination of carvedilol;
however, carvedilol blood levels may be increased (along with the
risk for carvedilol's side effects) if patients are taking any of
these drugs.
Carvedilol may increase the levels in the blood of cyclosporin (Sandimmune, Neoral), and the dose cyclosporin may need to be
adjusted when the two drugs are used together.
PREGNANCY: Safe use of carvedilol during pregnancy has not
been established.
NURSING MOTHERS: No studies with carvedilol are available
in nursing mothers; however, use is not recommended due to the risk
of a slow heart rate in the infant.
SIDE EFFECTS AND PRECAUTIONS: The most common side effects
of carvedilol are dizziness, edema (fluid accumulation), decreased
heart rate, diarrhea and postural hypotension (a rapid decrease in
blood pressure when going from the seated to the standing position
that causes light-headedness and/or fainting). Taking carvedilol
with food minimizes the risk of postural hypotension.
Other common side effects of carvedilol are irregular heart rhythm,
and abnormalities of vision.
Carvedilol should be used cautiously in patients who use diuretics or
who are elderly or have cirrhosis, asthma, peripheral vascular
disease, hyperthyroidism, Prinzmetal's variant angina (angina at
rest), and kidney disease.
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From the Doctors at MedicineNet.com  |
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Back to Medications IndexLast Editorial Review: 7/16/2005
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