Oxis Turbohaler (Formoterol Fumarate Dihydrate)

Formoterol fumarate is a bronchodilator that acts on the β2‑adrenergic pathway to relax airway smooth muscle.

• Asthma: improves control of symptoms and reduces the frequency of exacerbations.
• Chronic obstructive pulmonary disease (COPD): enhances lung function and decreases rescue‑inhaler use.
• Exercise‑induced bronchoconstriction: prevents airway narrowing during physical activity.

• Formoterol binds selectively to β2‑adrenergic receptors on airway smooth‑muscle cells, activating adenylate cyclase and increasing intracellular cyclic AMP. Elevated cAMP leads to relaxation of bronchial smooth muscle, producing sustained bronchodilation for up to 12 hours after inhalation.

Formoterol may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Throat irritation: mild discomfort or dryness in the throat.
• Cough: transient coughing after inhalation.
• Headache: mild to moderate headache.
• Tremor: fine muscle tremor, often of the hands.
• Palpitations: sensation of rapid or irregular heartbeat.
• Nasal congestion: mild blockage of the nasal passages.

Serious or Rare Side Effects

• Paradoxical bronchospasm: sudden worsening of breathing difficulty.
• Cardiovascular events: arrhythmia, tachycardia, or hypertension.
• Hypokalemia: low blood potassium levels.
• Hyperglycaemia: elevated blood glucose, especially in diabetic patients.

When using Oxis Turbohaler, consider the following safety measures:

• Assess asthma/COPD severity: ensure the patient is appropriate for a long‑acting β2‑agonist.
• Review cardiovascular history: patients with arrhythmia or hypertension need close monitoring.
• Avoid excessive use: limit rescue inhaler reliance to prevent tolerance.
• Monitor for paradoxical bronchospasm: discontinue if breathing worsens after use.
• Educate on inhaler technique: proper use maximises drug delivery and reduces side effects.
• Store at ambient temperature: keep below 25 °C, in the original packaging, protected from moisture.

Formoterol can interact with several drug classes, requiring attention to avoid reduced efficacy or increased adverse effects.

Major Interactions (Avoid)

• Non‑selective β‑blockers: may diminish bronchodilator response and precipitate bronchospasm.
• Monoamine oxidase inhibitors (MAOIs): risk of severe hypertension when combined with sympathomimetic drugs.

Moderate Interactions (Monitor Closely)

• Diuretics: may exacerbate hypokalemia caused by β2‑agonist activity.
• Theophylline: additive bronchodilator effect can increase risk of tremor and tachycardia.
• Corticosteroids inhaled: may enhance systemic absorption, requiring dose adjustment.
• Anticholinergic bronchodilators: combined therapy may increase cardiovascular load.
• Certain antidepressants (e.g., SSRIs): monitor for heightened tachycardia.