Albuterol
"My doctor put me on a dosage of 2 puffs every 4 hours as needed but when I used this amount I developed almost continuous anxiety attacks, insomnia, back and arm pain, wheezing, muscle spasm and jerking in extremities, and pounding in my ears.  I was greatly distressed until I read this article and discovered that all of these symptoms are side effects of the albuterol."