If you read the Xopenex literature, the warnings are almost exactly the same as Albuterol.
http://www.xopenex.com/xopenexProviders/XopenexUDV400437-R5.pdf
It also still has some dosing restrictions which makes it complicated to get approvals for a continuous neb to be done. The HR for the 1.25 mg of Xopenex was actually slightly higher than the 2.5 mg Albuterol in some studies which I believe are mentioned in the above link.
We follow the national Asthma and COPD guidelinse. For CHF, we may try one albuterol/atrovent but usually only with a COPD/Asthma history.
If the airways are not bronchospastic, Albuterol or Xopenex may offer nothing. That is usually the case in CHF and PNA.
Our RT department does about 300 - 400 nebulizers per day and use a variety of meds. Usually if no difference is noted, albuterol will be the drug of choice. If the patient is tested with spirometry for Xopenex and if there is little or not difference between their previous results, they'll get albuterol unless they have terriffic insurance and insist on Xopenex. Right now the majority of patients use albuterol.
We rely on diagnositic values as well as what the patient says. When Xopenex first came out over a decade ago, we sold it heavily because of a special incentive and a little grant money for a study. We put it up to be the greatest thing since peanut butter and jelly. The hype worked...temporarily. We had literally used a "placebo" type effect with the Xopenex make them believe it was the best thing ever. For some, you can do the "Coke" and "Pepsi" challenge and a few would think they know the difference.
When I am in a rescue situation, I am going to give the patient all the confidence I can in whatever drug or equipment I am using. I DO NOT say X is better than A or an MDI is worthless or better or a neb is mostly wasted. I give NO negatives even if all the studies indicate some therapies are crap but that is all I have at the moment. However, I may point out some differences if I know they are already using something else. Right now that is our biggest challenge with the new HFA propellant MDIs. "It doesn't feel the same". And it doesn't.
In the acute phase of COPD and Asthma, the bronchodilator may bring some relief, but the majority of the problem will be resolved by treating the underlying cause definitively. Sometimes too much time is wasted by "try another neb" instead on moving quickly on down the protocol pathway for asthma or COPD.