While it is recognized that β2 adrenergic receptors are the predominant receptors on bronchial smooth muscle, data indicate that there are beta receptors in the human heart, 10–50% of which are β2 adrenergic receptors. The precise function of these receptors has not been established. However, all β adrenergic agonist drugs can produce a significant cardiovascular effect in some patients, as measured by pulse rate, blood pressure, and restlessness symptoms, and/or electrocardiographic (ECG). Approval and names
Levosalbutamol is the INN while levalbuterol is the USAN. Levalbuterol was approved in the United States as a solution to be used with a nebulizer device in March 1999 and in March 2015 became available in a formulation with a metered-dose inhaler under the trade name Xopenex HFA (levalbuterol tartrate inhalation aerosol). See also
Salbutamol — the racemic mixture containing both (R)-(−)- and (S)-(+)-enantiomers

References
External links
"Levalbuterol". Drug Information Portal. U.S. National Library of Medicine.
Visceroptosis is a prolapse or a sinking of the abdominal viscera (internal organs) below their natural position. "Ptosis" being the defining term, any or all of the organs may be displaced downward. When only the intestines are involved, the condition is known as enteroptosis. When the stomach is found below its normal position, the term gastroptosis is used. The condition exists in all degrees of severity and may not give rise to any adverse symptoms. Generally, when adverse symptoms are associated with the condition, however, there may be loss of appetite, heartburn, nervous indigestion, constipation, diarrhea, abdominal distention, headache, vertigo, emaciation, and loss of sleep. Any or all of these symptoms may be present. The condition may be brought about by loss of muscular tone, particularly of the abdominal muscles, with relaxation of the ligaments that typically hold the viscera in place. Tightlacing has been held to be a cause as well. Corsets to reduce the circumference of womens waists have been used to enable fashionable styles occurring during several historical periods, such as the late 1800s and early 1900s, when these symptoms were described for treatment by physicians. Adverse symptoms may be alleviated by supporting the organs with a properly applied bandage, or other similar device. Rest in bed, attention to diet, hygiene, exercise, and general muscular strengthening will cure the majority of cases. In some cases, surgical intervention may become necessary.Visceroptosis is a known risk factor for the development of Superior mesenteric artery syndrome.