From the Research
Metoprolol is not as effective as propranolol for managing anxiety symptoms, due to its cardioselective properties and limited ability to cross the blood-brain barrier. While both are beta blockers, propranolol is non-selective and crosses the blood-brain barrier more readily, making it more effective for the physical symptoms of anxiety like tremors, palpitations, and sweating 1. Propranolol is typically prescribed at 10-40mg as needed before anxiety-provoking situations or 40-80mg daily for ongoing symptoms. Metoprolol, being cardioselective (primarily affecting beta-1 receptors in the heart), is less effective for the comprehensive management of anxiety symptoms. The difference in effectiveness stems from propranolol's ability to block both beta-1 and beta-2 receptors throughout the body, including those involved in the peripheral manifestations of anxiety.
Some studies have suggested that beta-blockers, including metoprolol, may not be effective in treating anxiety disorders, with a systematic review and meta-analysis finding no evidence for a beneficial effect of beta-blockers compared with either placebo or benzodiazepines in patients with social phobia or panic disorder with/without agoraphobia 2. However, propranolol has been found to be effective in treating stage fright and post-traumatic stress disorder (PTSD) 1.
It's worth noting that atenolol, another beta-blocker, has been found to be well-tolerated and effective among persons with anxiety disorders, with some patients preferring it over propranolol 3. However, more rigorously controlled empirical studies are needed to further substantiate this claim.
In terms of side effects, both metoprolol and propranolol can cause fatigue, dizziness, and lowered blood pressure, and neither should be stopped abruptly as this can cause rebound symptoms.
Overall, while metoprolol may not be as effective as propranolol for managing anxiety symptoms, it may still be used in certain situations, such as in patients with cardiovascular disease who also experience anxiety. However, the use of beta-blockers for anxiety disorders should be approached with caution, and more research is needed to fully understand their effectiveness and safety in this context.