Corticosteroids, such as dexamethasone and prednisone, are commonly used alongside chemotherapy. These drugs are synthetic versions of hormones naturally produced by the adrenal glands, and they are not the muscle-building anabolic steroids. Corticosteroids are powerful anti-inflammatory and immunosuppressive agents primarily used as supportive care. They help manage the intense side effects and complications of the cancer treatment itself, making the chemotherapy process safer and more tolerable. Their inclusion aims to preserve a patient’s quality of life rather than directly attacking cancer cells.
Controlling Nausea and Vomiting
The prevention and control of chemotherapy-induced nausea and vomiting (CINV) is a significant application of corticosteroids. Chemotherapy drugs trigger complex chemical pathways in the brain that lead to the vomiting reflex. Corticosteroids, most commonly dexamethasone, are routinely included in antiemetic regimens to help block these signals.
Dexamethasone enhances the effectiveness of other anti-nausea medications, such as serotonin (5HT3) and neurokinin-1 (NK1) receptor antagonists. This combination targets multiple chemical messengers involved in the nausea pathway, providing a robust defense against sickness. For maximum benefit, the steroid is administered as a “pre-medication” intravenously before the chemotherapy infusion begins to prevent nausea proactively.
The prophylactic use of the steroid continues for a few days after the session to manage delayed CINV, which occurs 24 to 120 hours following the infusion. By dampening the inflammatory response, the steroid helps keep the digestive system calm while chemotherapy metabolites circulate. This strategic, short-term dosing is crucial for patient comfort and ensuring chemotherapy cycles continue without interruption.
Mitigating Allergic and Infusion Reactions
Many chemotherapy agents, such as taxanes and monoclonal antibodies, risk causing acute hypersensitivity or infusion-related reactions (IRRs). These systemic, rapid immune responses range from mild symptoms like flushing and rash to severe reactions involving difficulty breathing and low blood pressure. Corticosteroids are essential components of the premedication strategy used before chemotherapy administration.
The steroid’s powerful anti-inflammatory and immunosuppressive actions help suppress the immune system’s overreaction to the infused drug. Drugs like dexamethasone are often given shortly before the infusion, combined with an antihistamine, to reduce the incidence of these acute reactions. Historically, the rate of hypersensitivity reactions to certain drugs like paclitaxel was significant without this premedication.
Pre-treatment with a corticosteroid is now standard practice that significantly lowers this risk, allowing the drug to be safely delivered. This preventive use ensures patients receive the full therapeutic dose without dangerous interruption. The steroid dose for this purpose is short-lived and focused entirely on the infusion day and the immediate preceding hours.
Reducing Tumor-Related Inflammation and Swelling
Corticosteroids also control symptoms directly caused by the cancer itself, especially when tumors cause local swelling or edema. This often occurs with tumors or metastases in the brain or spinal cord. Tumor growth in these confined spaces disrupts blood vessel integrity, leading to fluid leakage and swelling known as vasogenic edema.
This swelling places pressure on sensitive neurological structures, causing symptoms like severe headaches, vision changes, or pain. Steroids, such as dexamethasone, rapidly reduce this edema by decreasing the permeability of blood vessels around the tumor. Reducing this localized pressure leads to a quick improvement in neurological symptoms, sometimes within hours.
This temporary relief improves the patient’s functional status and quality of life. It provides crucial support while the patient waits for chemotherapy to begin shrinking the tumor mass.
Managing Common Steroid Side Effects
Corticosteroids are potent medications that can cause noticeable short-term side effects, despite their effectiveness in supportive care. Patients should be prepared to manage these effects.
Many patients experience difficulty sleeping, known as steroid-induced insomnia. To combat this, patients are advised to take all prescribed daily doses early in the morning. This prevents the stimulating effect from interfering with nighttime rest.
Other common side effects include increased appetite, which can lead to temporary weight gain and fluid retention. Steroids can also affect mood, causing anxiety, restlessness, or increased energy. Patients may also experience a temporary elevation in blood sugar levels, requiring glucose monitoring. Taking the oral dose with food can help mitigate stomach irritation.