Products
LABA is an acronym for , which means long-acting beta agonists (sympathomimetics). LABAs are mainly marketed as inhaled preparations (powders, solutions) administered with an inhaler such as a metered-dose inhaler, diskus, respimat, breezhaler, or ellipta. Some may also be given perorally. Salmeterol and formoterol were the first agents from this group to be approved in many countries in 1995. LABAs that are active for more than 24 hours are also referred to as VLABA, or as ULABA, , . LABA are contrasted with the short-acting beta2-sympathomimetics, known as SABA – – . SABAs include, for example, salbutamol (Ventolin). LABAs are also combined fixedly with other agents, particularly glucocorticoids for asthma therapy and with LAMAs such as tiotropium bromide or glycopyrronium bromide.
Structure and properties
LABAs are structurally related to the natural ligands epinephrine and norepinephrine. They can exist as racemates or as pure enantiomers.
Effects
LABAs (ATC R03AC) have sympathomimetic, bronchodilator, and some anti-inflammatory properties. Effects last from about 12 to more than 24 hours, depending on the active ingredient. The effects are due to selective binding to beta2-adrenoreceptors. This stimulates adenylyl cyclases, increasing the formation of cyclic adenosine monophosphate (cAMP). cAMP relaxes smooth muscle cells in the airways, mediating bronchodilatation.
Indications
LABAs are administered for the treatment of chronic obstructive pulmonary disease (COPD). Some are also approved for the treatment of bronchial asthma. For this, they must be combined with an inhaled glucocorticoid fix. Not all LABAs can be used for acute therapy of an asthma attack.
Dosage
According to the SmPC. Because of their long duration of action, LABAs need to be inhaled only once or twice daily (ULABA: once daily). This represents an advantage for adherence to therapy. Good instruction by healthcare professionals is necessary before first use.
Abuse
Beta2-sympathomimetics can be abused as doping agents in sports because of their bronchodilator and anabolic properties.
Agents
- Formoterol (Foradil, Oxis, combinations: Flutiform, Symbicort, Vannair, Foster).
- Indacaterol (Onbrez Breezhaler, combination: Ultibro Breezhaler) – ULABA
- Olodaterol (Striverdi Respimat, combination: Spiolto Respimat) – ULABA
- Salmeterol (Serevent, combination: Seretide).
- Vilanterol (combination: Anoro Ellipta, Relvar Ellipta) – ULABA
Not commercially available in many countries:
- Arformoterol
- Bambuterol
- Clenbuterol
Contraindications
Contraindications depend on the active ingredients. Contraindications include:
- Hypersensitivity
- Cardiac arrhythmia
- Prolongation of the QT interval
- Children and adolescents
- Pregnancy and lactation
Full precautions can be found in the drug label.
Interactions
Drug interactions are possible with the following agents, among others:
- Drugs that prolong the QT interval.
- MAO inhibitors, antidepressants
- Levodopa, levothyroxine, oxytocin
- Sympathomimetics
- Beta blockers
Adverse effects
The most common possible adverse effects include palpitations, muscle cramps, a tremor (shaking), headache, dizziness, upper respiratory tract infections, and restlessness. LABAs may cause cardiovascular effects such as an increase in pulse rate, an increase in blood pressure, cardiac arrhythmias or ECG changes, and may prolong the QT interval. They may cause paradoxical bronchospasm and lead to hypokalemia and hyperglycemia.