Pharmacology · Beta-2 adrenergic agonists

Formoterol !

A long-acting beta-2 agonist that also works within minutes. Maintenance bronchodilator in COPD; in asthma only with an inhaled steroid.

Updated 2026-11-01

Class: Beta-2 adrenergic agonists
Receptor: Beta-2 adrenergic receptor
ATC code: R03AC13

Also called: Eformoterol

Beta-2 adrenergic receptorFormoterol

The figure shows formoterol bound to the human beta-2 adrenergic receptor coupled to its Gs protein (cryo-EM).

Target in 3D: Beta-2 adrenergic receptor. PDB structure 7BZ2 (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Formoterol is a selective, full agonist of the beta-2 receptor. Like salbutamol it raises cyclic AMP and relaxes airway smooth muscle, so its effect starts within minutes; but its moderate lipophilicity lets it stay in the cell membrane near the receptor, so bronchodilation lasts about twelve hours.

Formoterol binds the beta-2 receptor as a full agonist
Cyclic AMP rises and airway muscle relaxes within minutes
The drug lingers in the membrane next to the receptor
Bronchodilation lasts about twelve hours

Pharmacokinetics

Absorption: Acts in the lung; part is absorbed into the blood
Metabolism: Glucuronidation and O-demethylation
Elimination: Mostly in urine, the rest in faeces
Half-life: About 7 hours after nebulisation
Onset and duration: Within minutes; peak effect after about 2 hours

Indications

Maintenance treatment of bronchoconstriction in COPD Chronic obstructive pulmonary disease (COPD) →
Asthma, only combined with an inhaled corticosteroid (for example budesonide + formoterol) Asthma →

Adverse effects

Common

Tremor and palpitations
Nausea, diarrhoea and dry mouth
Dizziness and insomnia
Nasopharyngitis

Contraindications

Use without an inhaled corticosteroid in asthma
Hypersensitivity to formoterol
Not started in acutely deteriorating COPD; caution in heart disease, seizure disorders and hyperthyroidism

Key interactions

Beta blockers: Reduce its effect and may cause bronchospasm
Theophylline, corticosteroids or non-potassium-sparing diuretics: Additive hypokalaemia and ECG changes
Monoamine oxidase inhibitors, tricyclic antidepressants or QT-prolonging drugs: Stronger cardiovascular effects
Other LABA-containing inhalers: Overdose risk; not combined

What is monitored

Heart rate and rhythm
Potassium and glucose in high-risk patients
Symptom control and reliever use

Administration and safety

Oral inhalation by nebuliser (single-use vials), dry powder inhaler or combination inhaler
Nebuliser vials are kept in their foil pouch and used only by inhalation
In asthma it is used only in a product or plan that includes an inhaled corticosteroid
Not given with another LABA product

Nursing care

Check heart rate and ask about palpitations and tremor
In asthma, check that an inhaled corticosteroid is part of the treatment
Teach that it is a maintenance medicine; a short-acting reliever is kept for sudden symptoms unless the plan uses a budesonide + formoterol inhaler for relief
Teach to report worsening breathing right after use (paradoxical bronchospasm)

Pregnancy and breastfeeding

Human data are limited; asthma control is the priority, because poorly controlled asthma harms mother and fetus.

Test yourself

Think of the answer, then tap the question to see it.

What distinguishes formoterol from salmeterol in onset?

Formoterol starts working within minutes (full agonist), while salmeterol has a slower onset.

When is formoterol contraindicated in asthma?

When used without an inhaled corticosteroid, because LABA monotherapy raises serious asthma-related events.

Which electrolyte is watched when formoterol is combined with diuretics or theophylline?

Potassium, because their hypokalaemic effects add up.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: DailyMed - FORMOTEROL FUMARATE solution (DailyMed (U.S. National Library of Medicine), 2025); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed., ch. 44 (McGraw Hill, 2023).

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Representative model, for educational purposes only.