How salbutamol works
Salbutamol is one of the fast-acting and short-acting beta-2 sympathomimetics (substances that selectively activate beta-2 receptors): It quickly provides bronchodilatation, but the effect does not last long (about four hours).
The salbutamol effect in detail
The autonomic (i.e., non-volitionally controllable) nervous system of the body consists of two parts that behave like opponents to each other: the parasympathetic nervous system (parasympathetic) and the sympathetic nervous system (sympathetic).
If the parasympathetic nervous system has the upper hand, the heartbeat slows down, digestion is stimulated, and basic muscle tension decreases. Physicians speak of the “feed-and-breed” reaction (“eat and reproduce”) or “rest-and-digest” reaction (“rest and digest”).
Salbutamol mimics the action of these stress hormones in the lungs, thus causing bronchial dilation and improving the uptake of oxygen and release of carbon dioxide. In the rest of the body, the drug exerts almost no effects (so it acts selectively on the lungs), reducing the risk of side effects.
Absorption, degradation and excretion
After its administration, salbutamol is absorbed into the blood via the lungs or intestines, depending on the dosage form (inhaler, tablet, solution). Within one day, 50 to 75 percent of the absorbed amount of active ingredient is excreted again via the kidneys.
When is salbutamol used?
The active ingredient salbutamol is approved for the treatment of:
- acute airway constriction (bronchoconstriction)
- bronchial asthma and chronic obstructive pulmonary disease (COPD)
- @ chronic bronchitis and emphysema
In addition, salbutamol is used to prevent allergy- or exercise-induced asthma attacks and as a labor inhibitor in preterm labor.
How salbutamol is used
Tablets, drops, juices and syrups are available for oral use. Furthermore, the active ingredient can also be administered in the form of an infusion or injection (syringe).
The salbutamol dosage in sprays is usually such that one to two sprays are sufficient to dilate the airways. If symptoms do not subside after a few minutes, inhalation can be repeated.
Depending on the type and severity of the airway disease, combination with longer-acting beta-2 sympathomimetics, glucocorticoids (“cortisone”), and/or antiallergic agents may be appropriate.
If the patient has a particularly severe asthma attack or if the effect of the medication does not seem to be sufficient, the emergency physician must be called as quickly as possible!
What are the side effects of salbutamol?
The most common side effects of salbutamol are tremor, nausea, headache, dizziness and cardiac arrhythmias. However, these usually occur only at the beginning of therapy and subside after one to two weeks.
What should be considered when using salbutamol?
Contraindications
Systemically acting preparations with salbutamol must not be used in:
- severe hyperthyroidism (hyperthyroidism)
- a certain form of chronic heart muscle disease (hypertrophic obstructive cardiomyopathy)
- pheochromocytoma (a tumor of the adrenal medulla)
- diseases with constriction of the vessels or with pathological dilatation of the vessel wall
Interaction
So-called beta-blockers (drugs used to treat cardiac arrhythmias and high blood pressure) act on the same target structure as salbutamol. When used at the same time, this can lead to a mutual weakening of effect. The use of beta-blockers is therefore not recommended in severe asthma.
Concomitant use with monoamine oxidase inhibitors (MAO inhibitors) and tricyclic antidepressants (e.g. amitriptyline, desipramine, imipramine) may increase the negative effects of salbutamol on the cardiovascular system.
Age restriction
The approval of salbutamol depends on the dosage form. Sprays are approved from the age of four years, tablets from the age of 14 years and drops from the age of two months.
Pregnancy and breastfeeding
Salbutamol can also be used during pregnancy and breastfeeding after consultation with the doctor. In the last trimester of pregnancy, it can be used to reduce or completely suppress premature labor (tocolysis). This often helps prevent premature birth.
How to get medicines containing salbutamol
Medicines containing salbutamol require a prescription in Germany, Austria and Switzerland and can be obtained from pharmacies on presentation of a valid prescription.
Unlike in Austria or Switzerland, salbutamol drops and tablets are available for ingestion in Germany. Conversely, in Austria and Switzerland there are juices or syrups containing salbutamol, which are not available on the market in Germany.
