Prednisone for Asthma and COPD Flares: Side Effects and Safe Use

Why is prednisone used for asthma and COPD flares?

Both asthma and COPD exacerbations involve inflammation that narrows and irritates the airways. Prednisone and related corticosteroids (methylprednisolone, prednisolone) are powerful anti-inflammatory drugs that reduce this swelling rapidly — faster than any other available oral treatment.

For COPD exacerbations, the GOLD guidelines recommend a short course of oral corticosteroids — typically 40 mg prednisolone-equivalent for 5 days — as first-line treatment 1Ref 1Global Initiative for Chronic Obstructive Lung Disease (2024).Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease (2024 Report).Recommendation for 5-day 40 mg prednisolone-equivalent course for COPD exacerbations; longer courses increase pneumonia risk. For asthma flares not responding to inhaled bronchodilators, oral steroids are similarly central to treatment, with the GINA strategy supporting their use for moderate-to-severe exacerbations 2Ref 2Global Initiative for Asthma (GINA) Science Committee (2024).Global Strategy for Asthma Management and Prevention.Oral corticosteroids for moderate-to-severe asthma exacerbations not responding to inhaled bronchodilators; typical 5–14 day course; continuation of inhaled controller medications during OCS use.

The goal is to break the inflammatory cycle quickly so the airway can recover. A short course achieves this without the cumulative risks associated with long-term steroid use.

What side effects should I expect from a short prednisone course?

Most side effects of a short steroid burst are temporary and resolve when the course ends. Common ones include:

Sleep disruption Prednisone is stimulating. Many people find it harder to fall asleep or stay asleep, especially if they take the dose in the afternoon or evening. Taking the full dose in the morning with food is usually recommended to minimize this.

Increased appetite and fluid retention You may feel hungrier than usual and notice some puffiness, particularly in the face. This is temporary and resolves when the course ends.

Mood changes Prednisone can cause irritability, anxiety, a sense of heightened energy, or in some people, low mood. These shifts are real and can be significant. If you feel unusual psychological distress, inform your clinician.

Elevated blood sugar Prednisone raises blood glucose in almost everyone, predominantly in the afternoon and evening 3Ref 3Tamez-Pérez HE, Quintanilla-Flores DL, Rodríguez-Gutiérrez R, González-González JG, Tamez-Peña AL (2015).Steroid Hyperglycemia: Prevalence, Early Detection and Therapeutic Recommendations: A Narrative Review.Prednisone causes predominantly postprandial/afternoon hyperglycemia; incidence of steroid-induced hyperglycemia 34–56% in patients without prior diabetes; glucose management recommendations during short courses. In people with diabetes, this can be substantial and may require temporary adjustment of diabetes medications. In people without known diabetes, blood sugar typically returns to normal after the course ends.

Increased blood pressure A modest rise in blood pressure is common during the course.

Stomach irritation Prednisone can irritate the stomach lining. Take it with food. If you have a history of peptic ulcer disease, tell your prescriber.

What about more serious side effects?

Serious side effects become a concern mainly with prolonged or repeated courses, not a single short burst. That said, some risks are worth knowing:

Bone density A single short course does not significantly affect bone density. Repeated or long-term use does — people who take steroids frequently should discuss bone protection (including calcium, vitamin D, and possibly a bone-protective medication) with their clinician.

Adrenal suppression A course of five to seven days at standard doses does not usually suppress the adrenal gland's ability to make cortisol. Longer courses or very high doses can. If you are told not to stop abruptly, follow that instruction.

Immune suppression and infection risk Short courses modestly reduce infection-fighting capacity. This is relevant if you have a known infection or are at high risk — discuss with your clinician.

The GOLD guidelines note that longer courses of oral corticosteroids increase the risk of pneumonia and other adverse outcomes in COPD patients, reinforcing why a 5-day course is preferred over longer regimens 1Ref 1Global Initiative for Chronic Obstructive Lung Disease (2024).Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease (2024 Report).Recommendation for 5-day 40 mg prednisolone-equivalent course for COPD exacerbations; longer courses increase pneumonia risk.

How should I take a short prednisone course correctly?

• Take it with food to reduce stomach irritation.
• Take the full dose in the morning if your clinician has not specified otherwise — this aligns with the body's natural cortisol rhythm and minimizes sleep disruption.
• Do not skip doses and do not stop early because you feel better. The course is designed to be completed.
• If you have diabetes: monitor blood sugar more frequently during the course, especially in the afternoon and evening 3Ref 3Tamez-Pérez HE, Quintanilla-Flores DL, Rodríguez-Gutiérrez R, González-González JG, Tamez-Peña AL (2015).Steroid Hyperglycemia: Prevalence, Early Detection and Therapeutic Recommendations: A Narrative Review.Prednisone causes predominantly postprandial/afternoon hyperglycemia; incidence of steroid-induced hyperglycemia 34–56% in patients without prior diabetes; glucose management recommendations during short courses. Contact your care team if readings are significantly elevated.
• Inform any other clinicians you see that you are taking prednisone — it can interact with several medications and affects clinical interpretation of blood tests.

If your symptoms do not improve or worsen despite completing the course, contact your clinician rather than requesting another round without evaluation.

When should I call my doctor during a prednisone course?

Contact your clinician or seek urgent care if: - Breathing does not improve within 24–48 hours of starting the course - You develop fever or new symptoms suggesting infection - Blood sugar rises to a level your diabetes care team has told you to report 3Ref 3Tamez-Pérez HE, Quintanilla-Flores DL, Rodríguez-Gutiérrez R, González-González JG, Tamez-Peña AL (2015).Steroid Hyperglycemia: Prevalence, Early Detection and Therapeutic Recommendations: A Narrative Review.Prednisone causes predominantly postprandial/afternoon hyperglycemia; incidence of steroid-induced hyperglycemia 34–56% in patients without prior diabetes; glucose management recommendations during short courses - You experience severe mood changes, hallucinations, or unusual behavior - You are vomiting and cannot keep the tablets down

A Gale primary-care clinician can prescribe and monitor a steroid burst for an asthma or COPD flare and advise on managing side effects given your individual health history.