Fluticasone Propionate
Fluticasone propionate is a potent, synthetic **glucocorticoid** primarily utilized in veterinary medicine as an inhaled aerosol. * **Primary Uses**: It is highly effective for managing chronic inflammatory airway diseases, such as **feline asthma**, **chronic tracheobronchial disease in dogs**, and **recurrent airway obstruction (RAO/heaves)** or inflammatory airway disease (IAD) in horses. Nasal formulations may also be used for allergy-related chronic rhinosinusitis. * **Clinical Advantage**: Because it is delivered directly to the respiratory mucosa via a metered-dose inhaler (MDI) and a species-specific spacer, it provides excellent local anti-inflammatory effects while significantly minimizing the systemic side effects typically associated with oral or injectable steroids. * **Potency**: It possesses an affinity for human glucocorticoid receptors that is 18 times greater than that of dexamethasone.
Mechanism: Fluticasone exerts its effects by binding to cytosolic **glucocorticoid receptors** in the respiratory mucosa. **Mechanism Pathway**: Receptor binding → Translocation of the receptor-ligand complex to the nucleus → Alteration of gene transcription → **Inhibition of pro-inflammatory mediators** (such as cytokines, prostaglandins, and leukotrienes) → Decreased airway inflammation, reduced mucosal edema, and lowered airway hyperreactivity. *Note: The drug is highly lipophilic, allowing for prolonged retention in lung tissue, and undergoes extensive first-pass metabolism, which limits systemic bioavailability if swallowed.*
Dosing by species
- Treatment of feline 'asthma' · one puff of the 44 micrograms/puff MDI · Inhalation · q12h · Initially try this dose. Study showed 44, 110, and 220 mcg all significantly reduced eosinophils in airway lavage fluid.
- Feline asthma (signs occurring more than once per week) · one puff of 110 micrograms fluticasone MDI · Inhalation · q12h · Use a delivery device (e.g., AeroKat) with a spacer. Cats with more serious disease may require the 220 micrograms MDI. Breathe in and out 7-10 times with mask in place. Give prednisolone at 1-2 mg/kg PO twice daily for 5-7 days initially, then taper over 2-3 months.
- Inflammatory airway disease (IAD) in young racehorses · Weeks 1 and 2: 2200 micrograms (10 puffs) twice daily. Weeks 3 and 4: 2200 micrograms (10 puffs) once daily. · Inhalation · q12h then q24h · 4 weeks · Use a delivery device (e.g., Aeromask or Equine-haler). Recheck in 4 weeks to determine further treatment.
- Moderate recurrent airway obstruction (RAO/heaves) · Week 3: 2200 micrograms (10 puffs) twice daily. Week 4: 2200 micrograms (10 puffs) once daily. End of 4 weeks (if good response): 2200 micrograms (10 puffs) once every other day. · Inhalation · q12h, then q24h, then EOD · Maintenance · Begin stringent environmental control and systemic prednisone. Add fluticasone at week 3 with salmeterol 210 mcg (10 puffs).
- Prevention of exacerbations of RAO · 6 mg · Inhalation · q12h · Using the EquineHaler. Highly likely that a lower dose can be used.
- Adjunctive treatment of chronic tracheobronchial disease (excessive side effects from oral steroids) · 110 microgram or 220 microgram (1 puff) · Inhalation · q12h · Use a delivery device (e.g., AeroDawg). Ensure a tightly fitting face mask and count 7-10 respirations after actuating the MDI into the spacer.
Routes of administration
Contraindications
- Hypersensitivity to fluticasone
- Acute bronchospasm or status asthmaticus (not a rescue inhaler)
Adverse effects
- Pharyngitis (reported in humans)
- Upper respiratory infections (reported in humans)
- Hypothalamic-pituitary-adrenal (HPA) axis suppression (rare with inhaled therapy, but possible with chronic high doses)
- Cushingoid effects (with chronic overdosage)
- Paradoxical bronchospasm (rare)
Drug interactions
- Ketoconazole · Inhibits CYP3A4 isoenzymes; theoretically could increase systemic fluticasone levels.
- Other CYP3A4 inhibitors · May decrease the metabolism of fluticasone, potentially increasing systemic exposure.
Monitoring
- Clinical efficacy (reduction in coughing, wheezing, or respiratory effort)
- Signs of HPA axis suppression or cushingoid changes (rare with inhaled therapy)
Overdose
Acute overdoses of this medication are unlikely to require treatment. Chronic overdoses could result in significant **HPA axis suppression** and **cushingoid effects**.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.