What is a recommended intramuscular (IM) injection of steroid for an asthma attack?

Intramuscular Steroid for Asthma Attack

For acute asthma exacerbations, intramuscular corticosteroids are NOT the preferred route—oral corticosteroids are equally effective and should be used first-line unless the patient is vomiting or unable to swallow. 1, 2, 3

When to Consider IM Steroids

IM corticosteroids should be reserved for specific clinical scenarios:

• Patients who are vomiting or unable to tolerate oral medications 2, 3
• Severely ill patients requiring immediate systemic effect when IV access is not available 2
• Concerns about medication adherence (though evidence for this indication is limited) 4

Key evidence: Oral administration is equally effective as intravenous or intramuscular therapy when gastrointestinal absorption is intact, and there is no advantage to parenteral routes in most cases. 2, 5

Recommended IM Steroid Regimens

For Adults:

Methylprednisolone 80-120 mg IM as a single dose is the most commonly recommended regimen 3, 6

• Relief may occur within 6-48 hours and persist for several days to two weeks 6
• For severe exacerbations, this can be followed by oral prednisone 30-60 mg daily for 5-10 days 2, 3

Alternative option: Hydrocortisone 200 mg IM, then transition to oral therapy once tolerated 1, 3

For Children:

Dexamethasone 0.6 mg/kg IM (maximum 16 mg) as a single dose 2

• This is the most studied IM regimen in pediatric populations 4
• Can be followed by oral prednisone 1-2 mg/kg/day (maximum 60 mg/day) for 3-5 days 2

Clinical Algorithm for Route Selection

Step 1: Assess ability to take oral medications

• If patient can swallow without vomiting → Use oral prednisone 40-60 mg 2, 3
• If patient is vomiting or unable to swallow → Proceed to Step 2

Step 2: Assess IV access and severity

• If IV access available and life-threatening features present → Use IV hydrocortisone 200 mg 1, 3
• If no IV access or moderate severity → Use IM methylprednisolone 80-120 mg 3, 6

Step 3: Reassess after 15-30 minutes

• Measure peak expiratory flow and clinical response 1, 3
• Transition to oral therapy as soon as patient can tolerate 2, 3

Important Evidence Considerations

No superiority of IM over oral: A Cochrane review of 9 studies (804 participants) found no difference in relapse rates between IM and oral corticosteroids (RR 0.94,95% CI 0.72 to 1.24), with potentially fewer adverse events in the IM group. 4

Dose equivalency matters less than route: Studies comparing different doses of corticosteroids (50 mg vs 500 mg hydrocortisone) showed no significant differences in outcomes, suggesting that adequate dosing at any level is more important than maximizing dose. 7

Critical Pitfalls to Avoid

• Do not delay corticosteroid administration while debating route—oral is faster to administer and equally effective 2, 5
• Do not use IM steroids routinely when oral administration is possible, as this adds unnecessary pain and cost without benefit 2, 4
• Do not give IM steroids as monotherapy without ensuring adequate follow-up oral corticosteroid course (5-10 days total) 2, 3
• Do not assume IM administration improves adherence without discussing this with the patient—many patients prefer oral therapy 4

Concurrent Therapy Requirements

Regardless of corticosteroid route, all patients require:

• High-flow oxygen (40-60%) to maintain SpO2 >92% 1, 3
• Nebulized beta-agonists (salbutamol 5 mg or terbutaline 10 mg) every 20-30 minutes initially 1, 8, 3
• Consider ipratropium bromide 0.5 mg added to nebulizer treatments for severe exacerbations 1, 8
• Peak flow monitoring at 15-30 minute intervals to assess response 1, 3