Levosalbutamol (
INNAn International Nonproprietary Name is the official non-proprietary or generic name given to a pharmaceutical substance, as designated by the World Health Organization...
) or
levalbuterol (
USANUnited States Adopted Names are unique nonproprietary names assigned to pharmaceuticals marketed in the United States. Each name is assigned by the USAN Council, which is co-sponsored by the American Medical Association , the United States Pharmacopeial Convention , and the American Pharmacists...
), trade name
Xopenex, is the
R-
enantiomerIn stereochemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are "non-superposable" , much as one's left and right hands are "the same" but opposite....
of the short-acting
β2-adrenergic receptor agonistβ2-adrenergic agonists, also known as β2-adrenergic receptor agonists, are a class of drugs used to treat asthma and other pulmonary disease states.-Uses:...
albuterol (salbutamol)Salbutamol or albuterol is a short-acting β
2-adrenergic receptor agonist used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease...
.
Uses
As a
bronchodilatorA bronchodilator is a substance that dilates the bronchi and bronchioles, decreasing airway resistance and thereby facilitating airflow. Bronchodilators may be endogenous , or they may be medications administered for the treatment of breathing difficulties...
, it is used to treat
asthmaAsthma is a predisposition to chronic inflammation of the lungs in which the airways are reversibly narrowed. Asthma affects 7% of the population of the United States, and 300 million worldwide...
and COPD. In general, levalbuterol has similar
pharmacokineticPharmacokinetics is a branch of pharmacology dedicated to the determination of the fate of substances administered externally to a living organism...
and
pharmacodynamicPharmacodynamics is the study of the physiological effects of drugs on the body or on microorganisms or parasites within or on the body and the mechanisms of drug action and the relationship between drug concentration and effect...
properties to albuterol; however, its manufacturer,
SepracorSepracor, Inc. is a pharmaceutical company founded in 1984 by Tim Barberich. It was originally located in Princeton, New Jersey and then re-located to Marlborough, Massachusetts.-History:...
, has implied (although not directly claimed) that the presence of only the
R-enantiomer produces fewer side effects.
Physicians sometimes elect to use levalbuterol in patients with a history of
supraventricular tachycardiaSupraventricular tachycardia is any tachycardic rhythm originating above the ventricular tissue. Paroxysmal supraventricular tachycardia ' is a rapid rhythm of the heart which involves an accessory pathway...
or other arrhythmias because it is thought that levalbuterol may produce less direct effects on β
1-adrenergic receptors in the heart. For similar reasons, some pediatricians also use levalbuterol for patients who experience hyperactivity or jitteriness from
racemicIn chemistry, a racemic mixture, or racemate, is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule...
albuterol.
Levosalbutamol vs. salbutamol
The use of levosalbutamol (levalbuterol) over the more traditionally used racemic salbutamol (albuterol) is controversial among health care professionals. That using levosalbutamol instead of salbutamol produces less direct effect on β1-adrenergic receptors and/or fewer cardiac side effects has been suggested, but not consistently demonstrated by long term, well-designed clinical trials.
There are differing opinions on whether there is sufficient therapeutic benefit to using levalbuterol that outweighs the 5-10 times higher price tag. In general, it appears that if a clinician and patient feel that a low dose of racemic mixture is causing undesirable side effects, levalbuterol may be a viable alternative.
Approval
Levalbuterol was originally available only as a solution for
nebulizerIn medicine, a nebulizer is a device used to administer medication to people in the form of a mist inhaled into the lungs. It is commonly used in treating cystic fibrosis, asthma, and other respiratory diseases....
and eventually become available as a
CFCA chlorofluorocarbon is an organic compound that contains carbon, chlorine, and fluorine. Also discussed in this topic are the hydrochlorofluorocarbons , which contain hydrogen in addition to carbon, chlorine, and fluorine. Most commonly, the term refers to a family of volatile derivatives of...
-free
metered dose inhalerA metered-dose inhaler is a device that delivers a specific amount of medication to the lungs, in the form of a short burst of aerosolized medicine that is inhaled by the patient. It is the most commonly used delivery system for treating asthma, chronic obstructive pulmonary disease and other...
under the trade name "Xopenex HFA (levalbuterol
tartrateA tartrate is a salt or ester of the organic compound tartaric acid, a dicarboxylic acid. Its formula is O−OC-CH-CH-COO− or C4H4O62−....
) Inhalation Aerosol". The
FDAThe Food and Drug Administration is a Government agency of the United States Department of Health and Human Services and is responsible for regulating and supervising the safety of foods, tobacco products, dietary supplements, Medication drugs, vaccines, Biopharmaceutical, blood transfusion,...
approval date was on March 11, 2005.
(See Official FAQ)
Additional studies
In a study conducted by Bill T. Ameredes, PhD, and colleagues from the University of Pittsburgh, that concluded that in combination corticosteroids treatments the (S)-isomer found in Albuterol had a profound nullifying effect. In the (R)- albuterol isomer it shown to enhance anti-inflammatory steroid treatment.
In other works he considers the combination (R)(S)-Albuterol a problematic drug.