Oncology Supportive Care: Anemia Management

Oncology Supportive Care

• This section covers supportive care in oncology, focusing on specific issues.

Anemia Part II

• Management of Anemia and Fatigue:

  • Erythropoiesis-stimulating agents (ESAs) are medications that stimulate red blood cell production, often used in patients with chronic kidney disease or undergoing chemotherapy.
  • ESAs mimic erythropoietin, a hormone that promotes red blood cell formation.
  • ESAs are usually initiated when hemoglobin (Hgb) drops below 10 g/dL, according to current guidelines.
  • Examples of ESAs include Epoetin and Darbepoetin alfa.
  • The goal of ESA use is to lessen the need for blood transfusions.
  • ESA use for cancer-associated anemia is not standard practice.
  • ESA use is associated with higher mortality rates and reduced chemotherapy outcomes and therefore is restricted to non-curative settings.

• Side Effects of ESAs:

  • Increased risk of overall mortality associated with ESA use, notably in patients with specific types of cancer.
  • Increased risk of thromboembolic events (VTE), including deep vein thrombosis and pulmonary embolism.
  • Increased risk of cardiovascular events (e.g., stroke, heart attack, heart failure) when prescribing higher target hemoglobin levels.
  • Possible stimulation of tumor progression in cancer patients, so use is not recommended in patients not undergoing active treatment or those with potentially curable conditions.

• Transfusion:

  • Blood transfusions can be used to manage anemia, especially if the patient is experiencing symptoms.
  • The goal of transfusion is maintaining hemoglobin (Hgb) between 8-10 g/dL.

Miscellaneous Antineoplastics

• Methotrexate Toxicity:

  • Methotrexate (MTX) remains a crucial drug in cancer and autoimmune disease treatment.
  • MTX works by inhibiting nucleotide synthesis in rapidly dividing cells.
  • Understanding potential toxicities & risk factors is critical for treatment optimization and to minimize adverse effects.
  • Regular follow-up with healthcare providers and supportive care are essential components in managing patients receiving MTX.
  • Mechanism of action: Inhibits nucleotide synthesis, affecting rapidly dividing cells by competing with the folic acid pathway of the nucleotide synthesis.
  • Hematologic toxicity can lead to bone marrow suppression, leukopenia, thrombocytopenia, and anemia, typically appearing within 1 to 3 weeks of treatment.
  • Hepatotoxicity can lead to liver damage and elevated liver enzymes, fibrosis, and cirrhosis, which risk increases especially in long-term use, in patients with liver conditions, or those consuming alcohol.
  • Renal toxicity can lead to acute kidney injury (AKI), often due to crystallization of the drug in renal tubules which can lead to tubular necrosis.
  • Gastrointestinal toxicity can cause severe mucositis and gastrointestinal bleeding, especially with high doses.
  • Risk factors for MTX toxicity: concurrent medications (e.g., NSAIDs, proton pump inhibitors), pre-existing conditions (e.g., liver disease, renal impairment, infections), and treatment duration and dosage.
  • Third space buildup: accumulation of MTX in body fluids, including pleural and ascites fluid, can significantly impact pharmacokinetics and lead to severe toxicity; draining this fluid may be crucial.

• Management strategies for methotrexate toxicity: Leucovorin rescue, hydration and urine alkalinization, regular monitoring of liver function, kidney function, blood cell counts. Serum MTX levels monitoring.

• Diarrhea:

  • Intensive loperamide therapy, using higher than the recommended dose, is often required to manage diarrhea caused by certain chemotherapy medications (e.g., irinotecan).

Dose Adjustment for Organ Dysfunction

• Dose adjustments for chemotherapy medications are necessary if patients have impaired organ function.
• Renal impairment adjustments are needed in certain conditions and for various drugs including: methotrexate, carboplatin, cisplatin, etoposide, bleomycin, tobotecan, lenalidomide.
• Hepatic impairment adjustments are needed in certain conditions and for various drugs including: doxorubicin, vincristine, vinblastine, docetaxel, paclitaxel, sorafenib, pazopanib.
• Conflicting recommendations exist for dose adjustments in cases of organ dysfunction.
• Many drugs haven't been extensively studied in patients with impaired organ function.