Is low-dose Zyprexa (olanzapine) effective for cancer treatment?

Low-Dose Olanzapine (Zyprexa) for Cancer Treatment

Low-dose olanzapine (Zyprexa) is not effective as a direct cancer treatment but has significant value in cancer supportive care, particularly for managing chemotherapy-induced nausea and vomiting (CINV), especially in breakthrough and refractory cases. 1

Role in Cancer Care

Established Uses:

• Antiemetic for Chemotherapy-Induced Nausea and Vomiting

  • Recommended for breakthrough nausea/vomiting when patients did not receive olanzapine prophylactically 1
  • Highly effective (93% response rate) for refractory CINV that doesn't respond to guideline-recommended prophylaxis 2
  • Can be used in combination with standard antiemetic regimens 1

• Dosing for CINV:

  • Standard dose: 10 mg daily 3
  • For elderly or patients with hepatic insufficiency: 0.25-0.5 mg initially 4

Other Potential Benefits in Cancer Care:

• Symptom Management:
  • Effective for tumor-induced nausea not related to chemotherapy 5
  • Can improve appetite in patients with cancer-related anorexia and weight loss 5
  • May have anxiolytic and mood-stabilizing effects beneficial in cancer patients 5

Emerging Research

While olanzapine is not approved as a direct cancer treatment, preliminary research suggests it may have some anti-cancer properties:

• A 2017 laboratory study found that olanzapine reduced survivin expression (a protein implicated in chemoresistance) in lung and pancreatic cancer stem cell lines 6
• This same study showed olanzapine sensitized cancer cells to chemotherapeutic agents like 5-fluorouracil, gemcitabine, and cisplatin 6

Safety Considerations

• Common Side Effects:

  • Sedation/drowsiness (most common)
  • Dizziness
  • Weight gain
  • Metabolic changes

• Special Populations:

  • Elderly patients: Use with caution due to increased risk of falls, cognitive impairment, and delirium 4
  • Hepatic dysfunction: Lower doses recommended (0.25-0.5 mg) 4
  • Boxed warning: Increased mortality risk in elderly patients with dementia-related psychosis 1

Clinical Application

1. For CINV management:

   • Add olanzapine 10 mg daily (or lower dose in elderly/hepatic dysfunction) when standard antiemetic regimens fail 1
   • Continue standard antiemetic regimen alongside olanzapine 1

2. For advanced cancer with nausea not related to chemotherapy:

   • Consider olanzapine 5-10 mg daily 3, 5
   • Monitor for sedation and adjust dose accordingly

Important Caveats

• Olanzapine should not be marketed or prescribed as a direct cancer treatment
• The potential chemosensitizing effects observed in laboratory studies 6 require further clinical validation
• When using for symptom management, start with lower doses in elderly patients and those with hepatic dysfunction 4
• Monitor for sedation, which is the most common dose-limiting toxicity 7