Oxis Turbuhaler (Formoterol Fumarate Dihydrate)

Formoterol fumarate dihydrate is a bronchodilator that acts on the smooth‑muscle tone of the airways. It is indicated for:

• Asthma: improves control of symptoms and reduces the frequency of exacerbations.
• Chronic obstructive pulmonary disease (COPD): maintains airway patency and eases breathing during stable disease.
• Exercise‑induced bronchoconstriction: prevents narrowing of the airways triggered by physical activity.
• Seasonal allergic rhinitis: provides relief of nasal congestion when combined with an intranasal steroid.
• Chronic bronchitis: helps to alleviate persistent cough and sputum production.

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

Formoterol may cause a range of adverse reactions, most of which are dose‑dependent and reversible.

Common Side Effects

• Throat irritation: mild discomfort or scratch‑like sensation in the throat.
• Cough: transient coughing immediately after inhalation.
• Headache: mild to moderate headache.
• Tremor: fine muscle tremor, often of the hands.
• Palpitations: sensation of rapid or irregular heartbeat.
• Dry mouth: reduced salivation leading to a dry feeling.

Serious or Rare Side Effects

• Paradoxical bronchospasm: sudden worsening of breathing difficulty.
• Cardiovascular events: arrhythmia, angina, or myocardial infarction.
• Hypokalemia: low blood potassium levels, potentially causing muscle weakness.
• Severe allergic reaction: rash, itching, swelling, or anaphylaxis.
• Hyperglycaemia: elevated blood glucose, particularly in diabetic patients.
• Pulmonary hypertension: increased pressure in lung arteries.

When using Oxis Turbuhaler, patients and healthcare providers should consider several safety measures.

• Assess respiratory status: evaluate baseline lung function before initiating therapy.
• Monitor for overuse: avoid exceeding prescribed inhalations to reduce risk of systemic effects.
• Review cardiovascular history: patients with arrhythmias or coronary disease need careful observation.
• Caution in pregnancy: discuss potential risks and benefits with a healthcare professional.
• Avoid use in uncontrolled asthma: ensure underlying inflammation is treated with an appropriate controller.
• Store at below 25°C: keep in the original packaging, protect from moisture and direct sunlight.

Formoterol may interact with several medication classes, altering its safety profile.

Major Interactions (Avoid)

• Non‑selective β‑blockers: may blunt bronchodilator response and precipitate bronchospasm.
• Monoamine oxidase inhibitors (MAOIs): increase risk of cardiovascular side effects.
• Diuretics (especially loop diuretics): may exacerbate hypokalemia.

Moderate Interactions (Monitor Closely)

• Theophylline: additive stimulant‑like effects on the heart.
• Anticholinergic bronchodilators: may increase risk of tachycardia.
• Certain antidepressants (e.g., SSRIs): potential for heightened tremor or palpitations.