Toprol-XL Side Effects

Generic Name: metoprolol

Please note - some side effects for Toprol-XL may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects by Body System

General

Metoprolol is generally well-tolerated. Ninety-four percent of patients from a large study reported "excellent" or "good" tolerability of metoprolol. Approximately 27% of patients experience at least one side effect from long-term studies, but they are usually mild and transient. Side effects may be more likely and more severe in patients who are slow metabolizers of metoprolol.

In a review of heart failure trials, beta-blockers (i.e., carvedilol, metoprolol, bisoprolol) were associated with increased risks of hypotension, dizziness, and bradycardia, but not fatigue compared with placebo. In addition, beta-blocker therapy was associated with fewer overall all-cause withdrawals and less heart failure deterioration than placebo.

Nervous system

Nervous system complaints include general fatigue in 1% to 10%, dizziness in 1% to 10%, headache in 0.3% to 4.0%, insomnia in 2%, nightmares in 1%, mental confusion, short-term memory loss, and somnolence. Anxiety, nervousness, hallucinations, and paresthesias have been associated with extended release preparations of metoprolol in postmarketing use.

Cardiovascular

Cardiovascular side effects reported in 3% of patients have included bradycardia and dyspnea. AV heart block, syncope, chest pain, hypotension, cold extremities, palpitations, peripheral edema, coronary artery spasm, congestive heart failure, and arterial insufficiency (usually of the Raynaud type) have been reported in 1% of patients. Very rarely, gangrene has been reported in patients with severe preexisting peripheral circulatory disorders. Cardiogenic shock has been reported in patients with acute myocardial infarction in postmarketing studies.

A 53-year-old male with hyperlipidemia, hypertension, single-vessel coronary artery disease, and tobacco abuse developed documented right coronary artery spasm inducible by intravenous ergonovine and made more inducible with intravenous metoprolol. The authors believe that, since beta-blockade may result in unopposed alpha stimulation, metoprolol (and other beta-blockers) are controversial in patients with coronary artery spasm (variant angina pectoris).

Gastrointestinal

Approximately four cases of retroperitoneal fibrosis, often presenting as a bowel or ureteral obstruction have been associated with the use of metoprolol. The mechanism by which beta-blockers cause this problem is unknown.

Gastrointestinal side effects have included diarrhea (5%). Nausea, dry mouth, gastric pain, constipation, flatulence, digestive tract disorders, and heartburn have been reported in 1% of patients. Vomiting has been reported frequently. Retroperitoneal fibrosis has also been reported, although a causal relationship to metoprolol has not been established.

Psychiatric

Psychiatric problems include depression in 2% to 5% of patients.

Respiratory

Small studies in patients with asthma reveal significant decreases in maximal midexpiratory flow (MMEF), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1) associated with metoprolol relative to placebo.

Metoprolol was associated with an increase in the number of obstructive breathing patterns in 5 of 12 obese male patients with hypertension.

Respiratory side effects reported in 1% of patients have included wheezing and dyspnea. Rhinitis has also been reported.

Metabolic

Metabolic side effects have included significant increases in VLDL cholesterol and total serum triglycerides, and significant decreases in HDL cholesterol. A case of hyperkalemia has been reported. At least one case of metoprolol-associated hypoglycemia has been reported. Very rarely, weight gain has also been reported.

Metabolic side effects have included weight gain.

Severe and symptomatic hyperkalemia associated with metoprolol has been reported in a 45-year-old male with diabetes, hypertension, and dialysis-dependent diabetic nephropathy. Cellular potassium channels are beta-receptor mediated.

The mechanism by which metoprolol induces weight gain is unknown. Some investigators have reported a 4% to 9% reduction in total energy expenditure and a 25% reduction in thermogenic response to food during beta-blocker treatment.

Hypersensitivity

Hypersensitivity side effects reported in 5% of patients have included pruritus and rash. Very rarely, worsening of psoriasis has also been reported.

A 72-year-old woman with a history of myocardial infarction, noninsulin-dependent diabetes mellitus, hypertension, chronic renal insufficiency, gout, and ACE inhibitor sensitivity was hospitalized for chest pain accompanied by pulmonary edema. During the first day of hospitalization, while intubated, she developed emergent hypertension, and was given metoprolol 5 mg IV. Within one hour, the patient developed profound tongue and lip swelling. Wheezing was absent. She was successfully treated with methylprednisolone and diphenhydramine. Besides ACE inhibitor sensitivity, there was no personal or family history of allergies, anaphylaxis, or atopic diathesis.

Genitourinary

Genitourinary complaints are limited mainly to male patients. Metoprolol may decrease free and total testosterone, although impotence occurs in only 0.2% of patients.

Dermatologic

Dermatologic side effects reported very rarely have included worsening of psoriasis. A case of generalized psoriasiform lesions has been reported. Urticaria has also been reported in postmarketing experience.

A 62-year-old man with ischemic heart disease developed a generalized, chronic, nummular, psoriasiform, erythematous rash that disappeared after metoprolol was withheld. Subsequent skin patch testing revealed sensitivity to metoprolol.

Musculoskeletal

There are approximately five case reports of severe myalgias/arthralgias in patients without a history of arthritis. In one, a 60-year-old male with hypertension developed a microcytic anemia, weight loss, myalgias, anorexia and fatigue within seven years after starting metoprolol and furosemide. The patient's signs and symptoms resolved within two months after discontinuing metoprolol. A review of the literature reveals that the most commonly affected joints are the knees. Associated complaints may include fever and chills.

Musculoskeletal side effects have been reported extremely rarely. Cases of a polymyalgia rheumatica-like syndrome and arthralgia have been reported. Very rarely, arthritis has also been reported.

Hepatic

A 56-year-old female with a history of migraine headaches developed seronegative hepatitis associated with metoprolol. Her signs and symptoms resolved within 48 hours after discontinuing metoprolol, and were reproducible on rechallenge.

Hepatic toxicity is reported in at least one case report.

Endocrine

Endocrine side effects including slightly decreased T3 concentrations (without changes in T4 concentrations) have been reported among patients with hyperthyroidism.

Ocular

Ocular side effects reported rarely have included blurred vision and dry eyes. Very rarely, photosensitivity has been reported.

Other

Other side effects including tinnitus and alopecia have been reported rarely. Photosensitivity and increased sweating have been associated with extended release preparations of metoprolol in postmarketing use.

Hematologic

Hematologic side effects including agranulocytosis, nonthrombocytopenic purpura and thrombocytopenic purpura have been associated with beta-blocking agents in general.

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