From the Research
Beta blockers should be used with caution in patients with myasthenia gravis (MG), but they are not absolutely contraindicated, as the most recent and highest quality study suggests that the benefit often outweighs the risk in well-controlled MG patients who require beta blockade for cardiac indications 1. When considering the use of beta blockers in MG patients, it is essential to weigh the potential benefits against the risks of exacerbating muscle weakness.
- The primary concern with beta blockers in MG patients is their potential to reduce sympathetic drive to skeletal muscles and possibly interfere with neuromuscular transmission, leading to worsening symptoms 2.
- However, cardioselective beta blockers like metoprolol or bisoprolol are preferred over non-selective agents when treatment is necessary for conditions like hypertension or heart failure, as they may have a lower risk of exacerbating MG symptoms 3.
- These medications should be started at low doses (e.g., metoprolol 12.5-25mg twice daily or bisoprolol 2.5mg daily) with gradual titration while monitoring for worsening MG symptoms 4.
- Close monitoring is essential, ideally with collaboration between the neurologist managing the MG and the physician prescribing the beta blocker, to ensure that the benefits of beta blocker therapy outweigh the risks in individual patients 5.
- If a patient experiences increased fatigue, ptosis, diplopia, or other signs of MG exacerbation after starting a beta blocker, the medication should be reduced or discontinued 1.