Pneumonia is an infection affecting one or both lungs, causing inflammation where air sacs (alveoli) fill with fluid or pus. This hinders oxygen entry into the bloodstream, leading to symptoms like cough, fever, chills, and breathing difficulties. While bacteria and viruses are common causes, fungi can also be responsible. Corticosteroids, often called steroids, are powerful medications mimicking natural hormones like cortisol from the adrenal glands. They are widely used to manage various inflammatory conditions due to their potent anti-inflammatory properties.
How Steroids Reduce Inflammation
Pneumonia triggers a significant inflammatory response in the lungs as the body’s immune system attempts to fight the infection. This inflammation causes blood vessels to dilate and become more permeable, leading to swelling and fluid accumulation in the delicate air sacs, which hinders effective oxygen exchange and worsens respiratory symptoms. Corticosteroids reduce this excessive inflammatory reaction by broadly modulating the body’s immune system.
They are synthetic versions of cortisol, a natural steroid hormone produced by the adrenal glands, which plays a role in regulating metabolism, immune response, and stress. Corticosteroids exert their effects by interacting with specific intracellular proteins called glucocorticoid receptors (GRs). Once a corticosteroid binds to a GR, this complex undergoes a conformational change and then translocates into the cell’s nucleus.
Inside the nucleus, the activated GR complex primarily influences gene expression through a process known as transrepression. This involves suppressing the transcription of genes that produce pro-inflammatory mediators such as cytokines (e.g., TNF-α, IL-1β) and chemokines, which are crucial for orchestrating the inflammatory cascade. By inhibiting these signals, corticosteroids dampen the overactive immune response that can contribute to lung tissue damage and systemic complications in pneumonia.
Beyond gene suppression, corticosteroids also affect various immune cells. They can reduce the survival and activation of inflammatory cells like eosinophils and modulate the function of macrophages, decreasing their production of pro-inflammatory cytokines. Additionally, they can inhibit the activation and proliferation of T cells and B cells, which are key components of the adaptive immune response. This multi-faceted action helps to decrease swelling and fluid buildup in the lungs, improving lung function and breathing.
When Steroids Are Prescribed for Pneumonia
Corticosteroids are not a universal treatment for all cases of pneumonia; their use is carefully considered in specific clinical scenarios. The decision to prescribe these medications is made by healthcare professionals based on the individual patient’s condition, the severity of their illness, and the likely cause of the infection.
Steroids are more commonly considered for individuals with severe pneumonia, particularly those who require hospitalization or admission to an intensive care unit (ICU). In these severe cases, the potential benefits of reducing widespread inflammation, which can lead to complications like acute respiratory distress syndrome (ARDS) or septic shock, often outweigh the associated risks. Recent guidelines recommend administering corticosteroids to adults hospitalized with severe bacterial community-acquired pneumonia (CAP). Studies indicate that in severe CAP, corticosteroids may reduce mortality, the need for mechanical ventilation, and shorten hospital stays.
A specific type of pneumonia where corticosteroids are frequently recommended is Pneumocystis jirovecii pneumonia (PJP), especially in patients with HIV infection who experience significant hypoxemia (low blood oxygen). In PJP, the inflammatory response can be particularly intense. Early initiation of steroids, typically within 72 hours of starting anti-PJP therapy, can significantly improve outcomes by reducing mortality and respiratory failure. The usual treatment regimen for PJP involves a tapering dose of prednisone over approximately 21 days. While evidence supports corticosteroids in severe bacterial pneumonia and PJP, their routine use in non-severe pneumonia or other types of viral and fungal pneumonias (like influenza) is not broadly supported by current research.
Important Considerations When Using Steroids
While corticosteroids can be life-saving in severe cases of pneumonia, their use is associated with a range of potential side effects. The occurrence and severity of these effects can depend on factors such as the dose, the duration of treatment, and the individual patient’s overall health. Healthcare providers must carefully weigh these risks against the anticipated benefits for each patient.
One of the most frequently observed side effects is an increase in blood sugar levels, which can be particularly problematic for individuals with pre-existing diabetes or those at risk of developing it. Patients may experience symptoms such as increased thirst and more frequent urination. Additionally, corticosteroids can suppress the immune system, which, while beneficial for inflammation, might theoretically increase susceptibility to secondary infections, although this risk is generally considered manageable during short-term use for pneumonia.
Other common adverse effects include changes in mood and behavior, such as irritability, anxiety, insomnia, and in some instances, more significant psychological disturbances like delirium. Fluid retention, leading to swelling in the extremities and potential weight gain, is also a known effect. Gastrointestinal irritation, including upset stomach, can occur, and is often mitigated by taking the medication with food.
For most cases of severe pneumonia, corticosteroids are typically prescribed for a short duration, often around 5 to 7 days, to limit the occurrence of these side effects. However, for specific conditions like PJP, longer courses, sometimes extending up to 21 days, are necessary and involve a gradual tapering of the dose to allow the body’s natural hormone production to recover. It is important for patients to avoid abruptly discontinuing steroid treatment, as this can lead to withdrawal symptoms and other complications.