FORAMET DRY POWDER

Indications

• Asthma
• Chronic obstructive pulmonary disease (COPD)

Dosage

Children: Refer to BNF for Children for specific dosing recommendations based on age and weight.

Adults: Refer to BNF for specific dosing guidance, typically involving the use of metered-dose inhalers or nebulizers.

Mechanism of action

Formoterol selectively binds to and activates beta2-adrenergic receptors, predominantly located in bronchial smooth muscle. This activation stimulates adenylyl cyclase, leading to increased levels of cyclic AMP (cAMP). Elevated cAMP causes relaxation of bronchial smooth muscle and dilation of the airways. Additionally, formoterol inhibits the release of hypersensitivity mediators, such as histamine and leukotrienes, from mast cells, further contributing to its bronchodilator effect.

Pharmacodynamics

As a bronchodilator, formoterol works locally in the lungs to relax smooth muscle and open the airways. It provides both a rapid onset of action and a prolonged duration, making it suitable for the management of chronic respiratory conditions. However, it should not be used as monotherapy in asthma management due to an associated increased risk of asthma-related death when not combined with inhaled corticosteroids.

Pharmacokinetics

Formoterol is administered via inhalation, allowing for direct delivery to the lungs. It has a rapid onset of action, typically within 2-3 minutes, and is characterized by a long duration of action, up to 12 hours. The pharmacokinetics of formoterol may vary based on individual patient factors, including age, lung function, and concurrent medications.

Contra-indications

• Hypersensitivity to formoterol or any of its components
• Severe uncontrolled asthma
• Acute bronchospasm
• Cardiovascular disorders
• Use of monoamine oxidase inhibitors (MAOIs) within 14 days

Adverse effects

• Tachycardia
• Palpitations
• Tremor
• Headache
• Nervousness
• Dizziness
• Nausea
• Muscle cramps
• Hypokalemia
• Hyperglycemia

Interactions

• Other sympathomimetics
• Beta-blockers (may reduce effectiveness of formoterol)
• Diuretics (may increase the risk of hypokalemia)
• Monoamine oxidase inhibitors (MAOIs)
• Tricyclic antidepressants

Precautions

• Caution in patients with cardiovascular disorders
• Caution in patients with diabetes mellitus
• Use with caution in patients with hyperthyroidism
• Monitor for worsening of asthma symptoms
• Avoid use as a rescue medication

Pregnancy

Formoterol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Consult a healthcare provider.

Breast-feeding

It is not known whether formoterol is excreted in human milk. Caution should be exercised when prescribing to nursing women.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Aerosol inhaler
• Dry powder inhaler
• Nebuliser solution

Indications

• Chronic asthma
• Chronic obstructive pulmonary disease (COPD)
• Reversible airways obstruction
• Prophylaxis of exercise-induced bronchospasm

Dosage

Children: Child 6–11 years: 12 micrograms twice daily (maximum daily dose 24 micrograms). Child 12–17 years: 12 micrograms twice daily, may

Adults: 6–12 micrograms by inhalation 1–2 times a day, increased if necessary up to 24 micrograms twice daily (max. per dose 36 micrograms), with a maximum daily dose of 48 micrograms.

Mechanism of action

Formoterol fumarate acts as an agonist at beta-2 adrenergic receptors located on bronchial smooth muscle. Upon binding, it activates adenylate cyclase, increasing intracellular cyclic AMP (cAMP) levels, leading to relaxation of bronchial smooth muscle and bronchodilation. This mechanism results in improved airflow and reduced resistance in the airways.

Pharmacodynamics

The pharmacodynamic effect of formoterol fumarate includes bronchodilation and relief of bronchospasm associated with asthma and COPD. The duration of action is approximately 12 hours, allowing for twice-daily dosing in many cases. Formoterol also exhibits some anti-inflammatory effects, although its primary role is as a bronchodilator.

Pharmacokinetics

Formoterol fumarate is well-absorbed following inhalation, with peak plasma concentrations typically occurring within 15 to 30 minutes. It undergoes extensive metabolism in the liver, primarily via the cytochrome P450 system. The elimination half-life is approximately 10 hours. Renal impairment may necessitate dose adjustments, especially in severe cases, while hepatic impairment is advised against due to the risk of unpredictable conversion to terbutaline.

Contra-indications

• Hypersensitivity to formoterol or any component of the formulation
• Severe impairment or cirrhosis of liver
• Rapidly deteriorating asthma

Adverse effects

• Anxiety
• Abnormal behaviour
• Muscle cramps
• Sleep disorders
• Akathisia
• Angioedema
• Bronchospasm
• Circulatory collapse
• Dizziness
• Hypokalaemia
• Hypotension
• Myocardial ischaemia
• Nausea
• Skin reactions

Interactions

• Concomitant use with theophylline and its derivatives may potentiate hypokalaemia
• Corticosteroids may also increase the risk of hypokalaemia
• Diuretics can lead to additive effects on serum potassium levels

Precautions

• Caution in patients with a history of cardiovascular disease
• Monitor potassium levels in patients on high doses
• Use with caution in patients with severe asthma or those requiring high doses of beta-agonists

Pregnancy

Manufacturer advises to avoid use due to lack of information on safety during pregnancy.

Breast-feeding

Manufacturer advises to avoid use due to lack of information on safety during breastfeeding.

Storage

Store in a cool, dry place away from direct sunlight. Keep out of reach of children.

Formulations

• Inhalation powder (various dosage forms including 6 micrograms, 12 micrograms, and 24 micrograms per dose)

Mechanism of action

Formoterol is a relatively selective long-acting agonist of beta₂-adrenergic receptors, although it does carry some degree of activity at beta₁ and beta₃ receptors. Beta₂ receptors are found predominantly in bronchial smooth muscle (with a relatively minor amount found in cardiac tissue) whereas beta₁ receptors are the predominant adrenergic receptors found in the heart - for this reason, selectivity for beta₂ receptors is desirable in the treatment of pulmonary diseases such as COPD and asthma. Formoterol has demonstrated an approximately 200-fold greater activity at beta₂ receptors over beta₁ receptors. On a molecular level, activation of beta receptors by agonists like formoterol stimulates intracellular adenylyl cyclase, an enzyme responsible for the conversion of ATP to cyclic AMP (cAMP). The increased levels of cAMP in bronchial smooth muscle tissue result in relaxation of these muscles and subsequent dilation of the airways, as well as inhibition of the release of hypersensitivity mediators (e.g. histamine, leukotrienes) from culprit cells, especially mast cells. Formoterol is a long-acting selective stimulator of the beta2-adrenergic receptors in bronchial smooth muscle. This stimulation causes relaxation of smooth muscle fibers and produces bronchodilation. Formoterol stimulates beta2-adrenergic receptors and apparently has little or no effect on beta1- or alpha-adrenergic receptors. The drug's beta-adrenergic effects appear to result from stimulation of the production of cyclic adeno-3'-5'-monophosphate (cAMP)by activation of adenyl cyclase. Cyclic AMP mediate numerous cellular responses, increased concentrations of cAMP are associated with relaxation of bronchial smooth muscle and suppression of some aspects of inflammation, such as inhibition of release proinflammatory mast cell mediators(eg histamine, leukotrienes).

Pharmacodynamics

Formoterol works locally in the lungs as a bronchodilator, relaxing smooth muscle and opening up the airways. It possesses both a rapid onset of action (approximately 2-3 minutes) and a long duration of action (up to 12 hours). The use of long-acting beta-agonists (LABAs), such as formoterol, without concomitant inhaled corticosteroids in asthmatic patients should be avoided, as LABA monotherapy has been associated with an increased risk of asthma-related death.