Flovent HFA | Pharmacology Mentor

Generic Name

Flovent HFA

Mechanism

Fluticasone propionate binds intracellular glucocorticoid receptors in airway smooth muscle and inflammatory cells.
This complex translocates to the nucleus, initiating transcription of anti‑inflammatory genes (e.g., lipocortin‑1) and repressing pro‑inflammatory cytokines (IL‑4, IL‑5, IL‑13, TNF‑α).
Result: ↓ eosinophilic inflammation, ↓ mucus production, ↑ airway smooth‑muscle tone, and ↓ bronchial hyperreactivity.

Pharmacokinetics

Absorption: Rapid pulmonary deposition, ~30–50 % of the dose reaches systemic circulation via mucosal and alveolar pathways.
Distribution: Extensive tissue binding; negligible systemic bioavailability after per‑dose; high protein binding (>90 %).
Metabolism: Hepatic CYP3A4‑mediated 20β‑hydroxylation; metabolites are inactive.
Elimination: Renal excretion (~90 % of parent and metabolites); half‑life ~7 h (pulmonary) and ~18 h (systemic).
Drug interactions: Potentiated effects with potent CYP3A4 inhibitors (ketoconazole, clarithromycin).

Indications

Moderate‑to‑severe persistent asthma in children ≥6 yrs and adults.
Asthma exacerbations as maintenance therapy post‑reliever.
Chronic obstructive pulmonary disease (COPD) exacerbation prevention (often combined with LABAs).

Contraindications

Contraindication	Key points
Hypersensitivity to fluticasone, propionate, or propellant	Avoid use; consider alternative NSA-ICS
Active systemic fungal infections	Systemic steroids contraindicated
Flovent HFA can aggravate oral candidiasis	Use oral rinses.

Warnings
• Respiratory infections: Monitor for post‑inhaler infections; caseate.
• Systemic adrenal suppression: Monitor in long‑term high‑dose therapy.
• Cushingoid features: Rare with standard doses; urgent review if signs appear.

Dosing

Age	Loading Dose	Maintenance Dose	Device	Notes
Children 6–11 yrs	200 µg twice daily for 1–2 weeks	200 µg once or twice daily (depending on severity)	Primogel® HFA
Adolescents & Adults	200 µg twice daily for 1–2 weeks	200 µg once or twice daily	Primogel® HFA
Adults (COPD)	200 µg twice daily for 1 week	200 µg twice daily	Primogel® HFA	Combine with LABA if needed

• Pulmonary administration: Shake, prime (if first‑use), mouth‑wash for 30 s, inhale slowly through the nose, hold breath 5–10 s.
• Co‑administration: If using LABAs or leukotriene modifiers, use a separate metered‑dose inhaler (MDI) or formoterol Salbutamol (Synergist®).

Adverse Effects

Common
• Oral candidiasis (thrush)
• Dysphonia (hoarseness)
• Local irritation (mouth, throat)

Serious
• Systemic hyper‑cortisolism (rare at therapeutic doses)
• Adrenal suppression (especially in poor inhaler technique, high cumulative doses)
• Ophthalmic complications (cataract, glaucoma) with chronic high exposure

Management
• Rinse mouth after use.
• Reduce dose or switch to non‑inhaled route if systemic signs appear.

Monitoring

Pulmonary function: Spirometry (FEV₁, FVC) every 4–6 weeks or upon symptom change.
Adrenal function: Morning cortisol if long‑term >6 mths or high dose.
Ocular exam: Annual eye checkup in patients >12 yrs on >6 mths therapy.
Inhaler technique: Re‑education at every encounter.

Clinical Pearls

Prime before first use – ensures patient receives the full label dose, critical for children.
Use a spacer – reduces deposition in the oropharynx, lowering thrush incidence.
Adhere to wash‑out periods – when switching between fluticasone and beclomethasone, allow 4–6 weeks to avoid over‑exposure.
CYP3A4 interaction – co‑administration with ketoconazole or macrolide antibiotics may increase systemic absorption by 20–40 %; consider dose adjustment.
Low‑dose flare‑up – in mild asthma, 200 µg twice daily may suffice; step down to 100 µg once daily if stable for 3–6 months.
Alternatives – if thrush persists despite rinsing, try natural mouth rinse (e.g., nystatin) or switch to mometasone furoate spacer formulation.

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• *References: UpToDate, FDA Label (Flovent HFA), American Thoracic Society, American College of Physicians.*