Coreg CR Side Effects

A brand-name prescription medication, Coreg CR contains carvedilol, which is part of a class of drugs called beta blockers. An extended-release formula, Coreg CR gradually puts out small amounts of medication, which disrupt electrical nerve impulses in your body and take strain away from your heart. Despite its effectiveness in the treatment of hypertension and congestive heart failure, Coreg CR poses a risk for side effects in some patients.

Hypotension

• Approximately 10 percent of patients who take Coreg CR for mild heart failure and 15 percent of those with severe heart failure develop hypotension or low blood pressure as a side effect of the medication, reports the U.S. National Library of Medicine. Around 3 percent of people experience pressure levels drop low enough to cause fainting. Hypotension is most likely to occur during the first 30 days of treatment.

Bradycardia

• Around .5 percent of patients develop bradycardia or an abnormally slow pulse from taking Coreg CR, according to the U.S. National Library of Medicine. If your pulse rate drops below 55 beats per minute, your doctor is likely to adjust your dosage.

Edema

• Around 3 percent of patients who take Coreg CR experience a worsening of congestive heart failure during the first three months of treatment, explains the U.S. National Library of Medicine. The most common sign of this adverse effect is a worsening of edema or an accumulation of fluid under your skin. You are most likely to notice edema as a swelling of your extremities.

Respiratory

• Respiratory side effects are also possible while taking Coreg CR, including coughing, nasal congestion and pharyngitis or inflammation of your pharynx, reports the U.S. National Library of Medicine.

Renal

• Infrequently, use of Coreg CR results in kidney dysfunction or failure. Symptoms of this dangerous side effect include less frequent urination, seizure or pain in your lower back or side. In most cases, kidney function returns to normal when patients stop taking the drug.

Hypersensitivity

• Though rare, Coreg CR has the potential to cause severe allergic reactions in some patients, warns the U.S. National Library of Medicine. One possible hypersensitivity response to the drug is anaphylaxis, which causes symptoms like chest pain and shortness of breath and can result in shock or even death. Angioedema, or swelling of your face or extremities, is another possible, but uncommon effect. Infrequently, patients require emergency medical treatment for life-threatening allergic skin rashes like Stevens-Johnson syndrome after taking Coreg CR.

Neurological

• As many as 32 percent of patients who take Coreg CR report dizziness, according to the U.S. National Library of Medicine. Because of this, avoid driving until you know how the drug affects you. Occurring in up to 7 percent of patients, headaches are another common neurological side effect. Less common effects include vertigo, tingling or numbness in your extremities, drowsiness and insomnia.

Gastrointestinal

• Gastrointestinal side effects of Coreg CR affect as many as 12 percent of patients, explains the U.S. National Library of Medicine. Among the reported symptoms are diarrhea, nausea, vomiting, inflammation of your gums, dry mouth and bloody stools.