From the Guidelines
Metoprolol succinate can cause several side effects, including fatigue, dizziness, slow heart rate, and low blood pressure, which can impact morbidity, mortality, and quality of life. When considering the management of patients with heart failure or hypertension, it is essential to weigh the benefits of metoprolol succinate against its potential side effects. According to the study published in Circulation 1, metoprolol succinate has been shown to reduce mortality in patients with heart failure, with a 34% reduction in mortality observed in the Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF). However, common side effects of metoprolol succinate include:
- Fatigue
- Dizziness
- Slow heart rate (bradycardia)
- Low blood pressure (hypotension)
- Cold hands and feet
- Headache
- Upset stomach
- Constipation
- Diarrhea
- Mild depression More serious but less common side effects include:
- Shortness of breath
- Worsening heart failure
- Severe dizziness
- Fainting
- Allergic reactions It is crucial to monitor patients for these side effects and adjust the dosage or switch to an alternative medication if necessary, as recommended by the study published in Annals of Internal Medicine 1. The benefits of metoprolol succinate in reducing mortality and morbidity in patients with heart failure and hypertension outweigh the risks of side effects, but close monitoring and careful management are essential to minimize adverse effects.
From the FDA Drug Label
ADVERSE REACTIONS Hypertension and Angina These adverse reactions were reported for treatment with oral metoprolol. Most adverse effects have been mild and transient. Central Nervous System Tiredness and dizziness have occurred in about 10 of 100 patients. Depression has been reported in about 5 of 100 patients. Mental confusion and short-term memory loss have been reported Headache, nightmares, and insomnia have also been reported. Cardiovascular Shortness of breath and bradycardia have occurred in approximately 3 of 100 patients. Cold extremities; arterial insufficiency, usually of the Raynaud type; palpitations; congestive heart failure; peripheral edema; and hypotension have been reported in about 1 of 100 patients Gangrene in patients with pre-existing severe peripheral circulatory disorders has also been reported very rarely Respiratory Wheezing (bronchospasm) and dyspnea have been reported in about 1 of 100 patients Rhinitis has also been reported. Gastrointestinal Diarrhea has occurred in about 5 of 100 patients Nausea, dry mouth, gastric pain, constipation, flatulence, and heartburn have been reported in about 1 of 100 patients. Vomiting was a common occurrence. Postmarketing experience reveals very rare reports of hepatitis, jaundice and non-specific hepatic dysfunction. Isolated cases of transaminase, alkaline phosphatase, and lactic dehydrogenase elevations have also been reported Hypersensitive Reactions Pruritus or rash have occurred in about 5 of 100 patients. Very rarely, photosensitivity and worsening of psoriasis has been reported. Miscellaneous Peyronie’s disease has been reported in fewer than 1 of 100,000 patients. Musculoskeletal pain, blurred vision, and tinnitus have also been reported There have been rare reports of reversible alopecia, agranulocytosis, and dry eyes. Discontinuation of the drug should be considered if any such reaction is not otherwise explicable. There have been very rare reports of weight gain, arthritis, and retroperitoneal fibrosis (relationship to metoprolol has not been definitely established) The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been reported with metoprolol.
The common side effects of metoprolol include:
- Central Nervous System: tiredness, dizziness, depression, mental confusion, short-term memory loss, headache, nightmares, and insomnia
- Cardiovascular: shortness of breath, bradycardia, cold extremities, arterial insufficiency, palpitations, congestive heart failure, peripheral edema, and hypotension
- Respiratory: wheezing, dyspnea, and rhinitis
- Gastrointestinal: diarrhea, nausea, dry mouth, gastric pain, constipation, flatulence, heartburn, and vomiting
- Hypersensitive Reactions: pruritus, rash, photosensitivity, and worsening of psoriasis
- Miscellaneous: Peyronie’s disease, musculoskeletal pain, blurred vision, tinnitus, reversible alopecia, agranulocytosis, and dry eyes 2
From the Research
Metoprolol Succinate Side Effects
- Adverse reactions associated with metoprolol succinate are mainly related to beta-2 blockade and alpha-blockade 3
- Non-selective beta-blockers, such as propranolol, or modestly beta-1 selective beta-blockers, like metoprolol, are associated with metabolic disturbance, bronchospasm, and epinephrine/hypertensive interaction 3
- Lipophilic beta-blockers, including metoprolol, appear in high concentrations in human brain tissue and are associated with side effects like insomnia, dreams, and nightmares 3
- Common side effects of metoprolol include temporary fatigue, dizziness, and headache 4
- Beta-blockers, including metoprolol succinate, can cause sexual dysfunction, particularly when combined with alpha-blockade 3
Specific Considerations
- Metoprolol succinate is generally well-tolerated, and its beta-1 selectivity may facilitate its administration to certain patients, such as asthmatics and diabetics, in whom non-selective beta-blockers are contraindicated 4
- The choice of beta-blocker is important, as benefit is not a class-effect, and some beta-blockers, like metoprolol succinate, have been shown to be more effective than others in certain indications 3, 5