Levosalbutamol, also known as levalbuterol, is a β₂-adrenergic receptor agonist used in the treatment of bronchospasm. Levosalbutamol is the (''R'')-(−)-

enantiomer In chemistry, an enantiomer (Help:IPA/English, /ɪˈnænti.əmər, ɛ-, -oʊ-/ Help:Pronunciation respelling key, ''ih-NAN-tee-ə-mər''), also known as an optical isomer, antipode, or optical antipode, is one of a pair of molecular entities whi ...

of its

prototype drug In pharmacology and pharmaceutics, a prototype drug is an individual drug that represents a drug class – group of medications having similar chemical structures, mechanism of action and mode of action. Prototypes are the most important, and typi ...

salbutamol Salbutamol, also known as albuterol and sold under the brand name Ventolin among others, is a medication that opens up the medium and large airways in the lungs. It is a short-acting β2 adrenergic receptor agonist that causes relaxation of ...

Medical use

Levosalbutamol is

indicated In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...

for the treatment or prevention of bronchospasm in people aged four years of age and older with reversible obstructive airway disease.

Comparison to salbutamol

Evidence is inconclusive regarding the efficacy of levosalbutamol versus

(albuterol) or salbutamol-levosalbutamol combinations, though levosalbutamol is believed to have a better safety profile due to its more selective binding to β₂ receptors (primarily in the lungs) versus β₁ (primarily in heart muscle). A 2013

systematic review A systematic review is a scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from published studies on ...

of the use of levalbuterol as a treatment for acute asthma found that it "was not superior to albuterol regarding efficacy and safety in subjects with acute asthma." The review concluded: "We suggest that levalbuterol should not be used over albuterol for acute asthma."

Adverse effects

Generally, levosalbutamol is well tolerated. Common mild side effects include an elevated heart rate, muscle cramps, and gastric upset (including heartburn and diarrhea). Symptoms of overdose in particular include: collapse into a

seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

; chest pain (possible precursor of a

heart attack A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom ...

); fast, pounding heartbeat, which may cause raised blood pressure (

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

); irregular heartbeat (

cardiac arrhythmia Arrhythmias, also known as cardiac arrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. Essentially, this is anything but normal sinus rhythm. A resting heart rate that is too fast – above 100 beat ...

), which may cause paradoxical lowered blood pressure (

hypotension Hypotension, also known as low blood pressure, is a cardiovascular condition characterized by abnormally reduced blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood and is ...

); nervousness and

tremor A tremor is an involuntary, somewhat rhythmic muscle contraction and relaxation involving neural oscillations, oscillations or twitching movements of one or more body parts. It is the most common of all involuntary movements and can affect the h ...

; headache; dizziness and

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

/vomiting; weakness or exhaustion ( medical fatigue); dry mouth; and

insomnia Insomnia, also known as sleeplessness, is a sleep disorder where people have difficulty sleeping. They may have difficulty falling asleep, or staying asleep for as long as desired. Insomnia is typically followed by daytime sleepiness, low ene ...

. Rarer side effects may indicate a dangerous allergic reaction. These include: paradoxical

bronchospasm Bronchospasm or a bronchial spasm is a sudden bronchoconstriction, constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylat ...

(shortness of breath and difficulty breathing); skin itching, rash, or hives (

urticaria Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and typically ...

); swelling (

angioedema Angioedema is an area of swelling (edema) of the lower layer of skin and tissue just under the skin or mucous membranes. The swelling may occur in the face, tongue, larynx, abdomen, or arms and legs. Often it is associated with hives, which are ...

) of any part of the face or throat (which can lead to voice hoarseness), or swelling of the extremities.

Pharmacology

Mechanism of action

Activation of β₂ adrenergic

receptors Receptor may refer to: *Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds ...

on airway smooth muscle leads to the activation of

adenylate cyclase Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction: :A ...

and to an increase in the intracellular concentration of 3',5'-cyclic adenosine monophosphate (cyclic AMP). The increase in cyclic AMP is associated with the activation of protein

kinase In biochemistry, a kinase () is an enzyme that catalyzes the transfer of phosphate groups from high-energy, phosphate-donating molecules to specific substrates. This process is known as phosphorylation, where the high-energy ATP molecule don ...

A, which in turn, inhibits the

phosphorylation In biochemistry, phosphorylation is described as the "transfer of a phosphate group" from a donor to an acceptor. A common phosphorylating agent (phosphate donor) is ATP and a common family of acceptor are alcohols: : This equation can be writ ...

myosin Myosins () are a Protein family, family of motor proteins (though most often protein complexes) best known for their roles in muscle contraction and in a wide range of other motility processes in eukaryotes. They are adenosine triphosphate, ATP- ...

and lowers intracellular ionic calcium concentrations, resulting in muscle relaxation. Levosalbutamol relaxes the smooth muscles of all airways, from the

trachea The trachea (: tracheae or tracheas), also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all animals' lungs. The trachea extends from ...

to the terminal bronchioles. Increased cyclic AMP concentrations are also associated with the inhibition of the release of mediators from mast cells in the airways. Levosalbutamol acts as a functional

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

that relaxes the airway irrespective of the spasmogen involved, thereby protecting against all

bronchoconstrictor Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath. Causes The condition has a number of causes, the most common bein ...

challenges. 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 In vertebrates, the circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the body. It includes the cardiovascular system, or vascular system, that consists of the heart a ...

effect in some patients, as measured by pulse rate, blood pressure, and restlessness symptoms, and/or

electrocardiographic Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity through repeated cardiac cycles. It is an electrogram of the heart which is a graph of voltage versus time of t ...

(ECG).

Society and culture

Levosalbutamol is on the

list of drugs banned by the World Anti-Doping Agency The International Standard for the Prohibited List is the standard published by the World Anti-Doping Agency (WADA) that lists substances prohibited in competitive sport. It is updated at least once per year as required by the World Anti-Doping Co ...

Economics

Levalbuterol is more costly than salbutamol.

Legal status

Levalbuterol was approved in the United States as a solution to be used with a

nebulizer In medicine, a nebulizer (American English) or nebuliser (English language, English) is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. Nebulizers are commonly used for the treatment of asthma, c ...

device in March 1999, and in March 2005, became available in a formulation with a

metered-dose inhaler A metered-dose inhaler (MDI) 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 usually self-administered by the patient via inhalation. It is the most commonly used ...

under the brand name Xopenex HFA (levalbuterol

tartrate A tartrate is a salt or ester of the organic compound tartaric acid, a dicarboxylic acid. The formula of the tartrate dianion is O−OC-CH(OH)-CH(OH)-COO− or C4H4O62−. The main forms of tartrates used commercially are pure crystalline ...

inhalation aerosol).

Names

Levosalbutamol is the international nonproprietary name and levalbuterol is the

United States Adopted Name A United States Adopted Name (USAN) is a unique nonproprietary name assigned to a medication marketed in the United States. Each name is assigned by the USAN Council, which is co-sponsored by the American Medical Association (AMA), the United St ...

. It is available in

Bangladesh Bangladesh, officially the People's Republic of Bangladesh, is a country in South Asia. It is the List of countries and dependencies by population, eighth-most populous country in the world and among the List of countries and dependencies by ...

as Purisal by Incepta Pharmaceuticals Ltd.

References

{{Authority control Beta2-adrenergic agonists Chemical substances for emergency medicine Enantiopure drugs Phenylethanolamines Phenols