What is the appropriate oral prednisone dose for a 338‑lb (≈153 kg) adult experiencing an acute asthma exacerbation?

Prednisone Dosing for Asthma Exacerbation in a 338-lb Patient

For a 338-lb (153 kg) adult with an acute asthma exacerbation, prescribe prednisone 40–60 mg orally once daily for 5–10 days without tapering, regardless of body weight. 1

Weight-Independent Dosing in Adults

• Adult prednisone dosing for asthma exacerbations is not weight-based—the standard 40–60 mg daily dose applies to all adults regardless of whether they weigh 120 lbs or 338 lbs. 1
• The American College of Allergy, Asthma, and Immunology explicitly recommends 40–80 mg/day until peak expiratory flow reaches 70% of predicted or personal best, with no adjustment for body weight. 1
• For outpatient "burst" therapy, 40–60 mg in a single morning dose or divided into two doses for 5–10 days is the evidence-based standard. 1

Route of Administration

• Oral administration is strongly preferred and provides equivalent efficacy to intravenous therapy when gastrointestinal absorption is intact. 1, 2
• Reserve IV hydrocortisone (200 mg immediately, then 200 mg every 6 hours) only for patients who are actively vomiting, severely ill, or unable to tolerate oral intake. 1
• A 2011 randomized controlled trial confirmed that oral prednisolone 100 mg daily was equally effective as IV hydrocortisone 100 mg every 6 hours in hospitalized adults with acute exacerbations. 2

Duration and Tapering

• No tapering is required for courses lasting 5–10 days, especially when the patient is concurrently using inhaled corticosteroids. 1, 3
• A 1993 double-blind trial demonstrated that tapering after 10 days of prednisolone 40 mg daily offered no advantage over abrupt cessation in patients using inhaled steroids (mean dose 908 mcg daily). 3
• Continue treatment until peak expiratory flow reaches ≥70% of predicted or personal best, which typically occurs within 5–10 days. 1

Dose Optimization

• Higher doses do not provide additional benefit—studies show that 40–60 mg daily is as effective as 200–500 mg doses but with fewer adverse effects. 1, 4
• A 1992 randomized trial found that hydrocortisone 50 mg IV every 6 hours (equivalent to ~40 mg prednisone daily) was equally effective as 500 mg doses in resolving acute severe asthma. 4

Concurrent Essential Therapy

• Administer nebulized or inhaled short-acting β-agonist (albuterol 2.5–5 mg) every 20 minutes for three doses, then every 1–4 hours as needed. 1
• Provide supplemental oxygen to maintain SpO₂ >92%. 1
• Continue or increase inhaled corticosteroids at a higher dose than pre-exacerbation. 1

Critical Pitfalls to Avoid

• Never delay systemic corticosteroids while giving repeated bronchodilators alone—early administration is essential because anti-inflammatory effects take 6–12 hours to appear. 1
• Do not use weight-based dosing in adults—this is a pediatric approach and leads to unnecessary overdosing in heavier patients without additional benefit. 1
• Avoid unnecessarily high doses (>60 mg daily for outpatient management), as they increase adverse effects without improving outcomes. 1, 4
• Do not taper short courses (<7–10 days), as this may lead to underdosing during the critical recovery period. 1, 3

Alternative Shorter Regimen

• Dexamethasone 16 mg orally daily for 2 days is an alternative that may allow faster return to normal activities (90% vs 80% at 3 days) with similar relapse rates compared to prednisone 50 mg for 5 days. 5
• However, the standard 5–10 day prednisone course remains the most widely validated approach. 1, 6