This is from AI:

While levalbuterol nebulization is generally safe, it's rare but possible for it to cause lung bleeding (epistaxis) or other respiratory issues as a side effect.
Here's a more detailed explanation:
Side Effects:
Levalbuterol, like other medications, can cause side effects, and while lung bleeding is not a common side effect, it's important to be aware of the possibility.
Other Respiratory Issues:
Other respiratory side effects that have been reported include asthma exacerbation, wheezing, and coughing.
Serious Reactions:
If you experience severe breathing problems, worsening asthma, or any other concerning symptoms after using levalbuterol, seek immediate medical attention.
Allergic Reactions:
Get medical help right away if you notice any symptoms of a serious allergic reaction, including rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.