Long-Term Side Effects of Metoprolol
Metoprolol can cause bradycardia, hypotension, fatigue, dizziness, and depression as common long-term side effects, with potential worsening of heart failure in susceptible patients. 1
Common Cardiovascular Side Effects
- Bradycardia: Heart rate slowing is one of the most common effects, occurring in approximately 15.9% of patients 2
- Hypotension: Can cause low blood pressure, dizziness, and lightheadedness 1
- Cold extremities: Arterial insufficiency (usually Raynaud type) occurs in about 1 of 100 patients 1
- Peripheral edema: Fluid retention in extremities 1
- Heart failure exacerbation: Can cause depression of myocardial contractility and may precipitate heart failure in susceptible patients 1
Central Nervous System Effects
- Fatigue/tiredness: Occurs in approximately 10% of patients on long-term therapy 1
- Dizziness: Reported in about 10% of patients 1
- Depression: Occurs in approximately 5% of patients on long-term therapy 1
- Mental confusion and short-term memory loss: Less common but documented 1
- Sleep disturbances: Including nightmares and insomnia 1
Respiratory Effects
- Dyspnea: Shortness of breath occurs in approximately 3% of patients 1
- Wheezing/bronchospasm: Occurs in about 1% of patients, particularly concerning in those with reactive airway disease 2
- Respiratory disorders: Reported in up to 12.9% of patients on long-term therapy 3
Gastrointestinal Effects
- Diarrhea: Occurs in about 5% of patients 1
- Nausea: Less common (approximately 1%) 1
- Dry mouth, gastric pain, constipation, flatulence: Each occurs in about 1% of patients 1
Metabolic Effects
- Masked hypoglycemia: Beta-blockers may mask tachycardia occurring with hypoglycemia, though other symptoms like dizziness and sweating remain 1
- Hyperglycemia: Can occur with long-term use 2
Other Long-Term Effects
- Sexual dysfunction: Including reduced libido and erectile dysfunction 1
- Rash/pruritus: Occurs in about 5% of patients 1
- Worsening of psoriasis: Rare but documented 1
- Laboratory abnormalities: Isolated cases of elevated liver enzymes (transaminases, alkaline phosphatase) 1
Special Considerations for Long-Term Use
Abrupt Discontinuation Risk
Never abruptly discontinue metoprolol after long-term use, as this can lead to:
- Severe exacerbation of angina
- Myocardial infarction
- Ventricular arrhythmias 1
When discontinuing, the dosage should be gradually reduced over 1-2 weeks with careful monitoring 1.
Monitoring Recommendations
For patients on long-term metoprolol therapy:
- Regular heart rate and blood pressure monitoring
- Assessment for signs of heart failure (weight gain, edema, dyspnea)
- Monitoring for depression and cognitive changes
- Periodic evaluation of glucose levels in diabetic patients
Heart Failure Considerations
In patients with heart failure, long-term metoprolol therapy requires special attention:
- Initial worsening of heart failure symptoms may occur but usually resolves with continued therapy 2
- Fluid retention can be managed by adjusting diuretic doses 2
- Long-term benefits typically outweigh initial side effects, with improved cardiac function over time 4
Management of Long-Term Side Effects
- Fatigue: Often resolves spontaneously within several weeks; if severe, dose reduction may be necessary 2
- Bradycardia: If symptomatic or if heart block occurs, dose reduction is recommended 2
- Hypotension: Can be managed by administering metoprolol and ACE inhibitors at different times of day or adjusting diuretic doses 2
- Bronchospasm: Consider lower doses administered three times daily instead of larger doses twice daily 2
Despite these potential side effects, metoprolol is generally well-tolerated in long-term use, with most adverse effects being mild and transient 5.