Managing Excessive Thirst in Patients Taking Pazopanib for Sarcoma
Excessive thirst in patients taking pazopanib for sarcoma should be managed with supportive therapies including artificial saliva, ice chips, chewing gum, and sugar-free candies while ensuring adequate hydration monitoring. 1
Understanding Pazopanib and Thirst
Pazopanib (Votrient) is an oral angiogenesis inhibitor that targets vascular endothelial growth factor receptors (VEGFR-1, -2, and -3), platelet-derived growth factor receptors (PDGFR-α and -β), and c-KIT. It is approved for the treatment of advanced soft tissue sarcomas and renal cell carcinoma 1.
Common adverse reactions to pazopanib include:
- Diarrhea (52%)
- Hypertension (40%)
- Hair color changes
- Nausea (26%)
- Anorexia (22%)
- Vomiting (21%)
- Fatigue (19%)
- Weakness (14%)
- Abdominal pain (11%)
- Headache (10%)
While excessive thirst is not specifically listed among the most common side effects, it can be related to several mechanisms:
- Direct medication effect
- Secondary to dehydration from gastrointestinal side effects
- Related to metabolic changes
Assessment of Excessive Thirst
When evaluating excessive thirst in a patient on pazopanib:
Check for signs of dehydration:
- Dry mucous membranes
- Decreased skin turgor
- Orthostatic hypotension
- Tachycardia
Laboratory evaluation:
- Electrolytes (particularly sodium)
- Blood glucose
- Renal function tests
- Liver function tests (pazopanib can cause hepatotoxicity)
Management Approach
1. Supportive Measures for Thirst Relief
- Artificial saliva products
- Ice chips (small amounts frequently)
- Sugar-free chewing gum
- Sugar-free hard candies
- Small sips of water throughout the day 1
2. Medication Adjustments
Consider taking pazopanib with food if approved by oncologist
- Studies show that 600mg pazopanib taken with food results in bioequivalent exposure to 800mg taken fasted 2
- This approach may reduce gastrointestinal side effects and improve patient comfort
Monitor liver function closely as pazopanib can cause hepatotoxicity
- Elevated levels of alanine (30%) and aspartate (21%) transaminase have been reported 1
3. Hydration Management
- Ensure adequate fluid intake (≥1.5L/day)
- Vary temperature and flavors of fluids
- Monitor for signs of overhydration if patient is drinking excessively
- Consider electrolyte-containing beverages if electrolyte imbalances are present
4. Addressing Underlying Causes
- If diarrhea or vomiting is contributing to dehydration:
- Implement anti-diarrheal medications as needed
- Consider antiemetics for nausea/vomiting
- Monitor for electrolyte abnormalities
When to Seek Additional Medical Attention
Advise patients to contact their healthcare provider if:
- Thirst becomes severe or unmanageable
- Signs of dehydration develop despite adequate fluid intake
- New symptoms develop such as confusion, extreme fatigue, or decreased urine output
- Significant weight changes occur
- Symptoms of hyperglycemia develop (increased urination, blurred vision)
Monitoring
- Regular assessment of hydration status
- Monitoring of electrolytes and renal function
- Liver function tests as recommended during pazopanib treatment
- Documentation of thirst severity and response to interventions
Important Considerations
- Pazopanib is effective for sarcoma treatment with progression-free survival benefits 3, 4, 5, so managing side effects rather than discontinuing therapy is preferred when possible
- Pazopanib should be continued at the appropriate dose while managing symptoms to maintain treatment efficacy
- Excessive thirst management should be integrated into the overall supportive care plan for patients on pazopanib
By implementing these strategies, excessive thirst can be effectively managed while maintaining the therapeutic benefits of pazopanib for sarcoma treatment.