Fenoterol – action, indications, dosage, contraindications

Fenoterol is a drug that is used to relax the smooth muscles of the bronchi. Due to this property, it is an effective drug in patients suffering from diseases in which the respiratory tract is narrowed, e.g. bronchial asthma or chronic obstructive pulmonary disease. How should fenoterol be dosed? What medications may the drug interact with? What are the possible side effects of fenoterol?

Drug manufacturer: depending on the preparation

Form, dose, packaging: inhalation spray: 0,1 mg / dose, pack of 10 ml; solution for injection and infusion: 50 mcg / ml, pack of 15 ampoules of 10 ml.

Availability category: Rp – prescription drug

Active substance: fenoterol

Fenoterol – action

Fenoterol is a drug known as a sympathomimetic, which is an agent that stimulates the sympathetic nervous system. It belongs to the group of selective beta2-adrenergic agonists. Beta2-adrenergic receptors are protein structures located, inter alia, in in the smooth muscles of blood vessels, bronchi or uterus. Their stimulation (agonistic effect on these receptors) causes the relaxation of the smooth muscles of these structures and intensifies the removal of residual bronchial secretions. Due to this mechanism, fenoterol, as a beta2-adrenergic agonist, produces its therapeutic effect within a few minutes. The effect of the drug lasts up to 3-5 hours after the smooth muscles relax.

Fenoterol – indications

Due to the fact that fenoterol induces a short-term relaxation of bronchial smooth muscles, preparations containing the drug are used in attacks of bronchial asthma and chronic obstructive pulmonary disease (COPD). These are conditions where the smooth muscles of the airways become over-contracted, resulting in intense, paroxysmal coughing and difficulty catching breath. Another indication for the use of fenoterol is the prevention of exercise-related asthma attacks. In addition, fenoterol is said to be a tocolytic drug, i.e. one that relaxes the smooth muscles of the uterus. This type of action prevents premature labor from occurring by interrupting it. This is advisable in a situation where your baby’s lungs have not yet developed adequately. The use of fenoterol delays labor by up to 48 hours, giving doctors time to administer glucocorticosteroids to support lung development in an unborn baby.

Fenoterol – dosage

Fenoterol is an agent that is used to stop asthma attacks and other conditions in which sudden, reversible narrowing of the airways occurs. The drug is usually not suitable for chronic treatment due to its quick and short duration of action (up to 5 hours). Chronic use may lead to bronchial hyperreactivity, and may also induce tolerance to fenoterol and other drugs with the same mechanism of action (salbutamol, terbutaline). Usually, one dose of the drug is used during an attack. This amount should produce the desired effect. However, if the attack persists after approx. 5 minutes, another dose should be administered. Do not exceed 8 doses a day. If there is a need to prevent exercise-induced asthma attacks, take 1-2 doses before you plan to exercise. In this case, it should not be exceeded 8 doses a day.

Fenoterol – contraindications

Contraindications to the use of fenoterol are: hypersensitivity to the active substance (fenoterol) or any of the auxiliary ingredients, cardiac arrhythmias and obstructive hypertrophic cardiomyopathy.

Fenoterol – warnings

Fenoterol should be used with special precautions in patients suffering from: uncontrolled diabetic conditions, hyperthyroidism, arterial hypertension, heart (e.g. arrhythmias) and blood vessel diseases, adrenal phaeochromocytoma, as well as in patients with a recent history of myocardial infarction. People who, despite the use of at least two doses of the drug, have not experienced the bronchial smooth muscle dilatation effect and the asthma attack has not receded, should also exercise particular caution. In this case, the attending physician should be contacted. The drug should be used with caution in pregnant women, because fenoterol inhibits the contraction of smooth muscles of the uterus.

Fenoterol – interactions

Fenoterol may interact with other drugs having the same mode of action, theophylline and anticholinergics. These groups of drugs may increase the effect of fenoterol and increase the risk of side effects. Fenoterol should not be combined with opposing drugs (beta-blockers). The drug should be used with caution with: MAO inhibitors, tricyclic antidepressants, as well as general anesthetics.

Fenoterol – side effects

Typical side effects of fenoterol are hypokalaemia, arrhythmias, muscle tremors, increased glucose levels in diabetics, and urinary incontinence (especially in the elderly).

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