What is the recommended dosage of propranolol (beta-blocker) for treating hemangiosarcoma in dogs?

Propranolol Dosage for Canine Hemangiosarcoma

For canine hemangiosarcoma, propranolol should be dosed at 1-3 mg/kg daily, divided into 2-3 doses, with careful monitoring for cardiovascular side effects.

Dosing Recommendations

• Starting dose should be 1 mg/kg daily divided into 2-3 doses, with gradual titration over 1-2 weeks to minimize side effects 1
• Target maintenance dose of 2-3 mg/kg daily for most cases, divided into 2-3 daily doses 1
• Maximum dose for non-responders should not exceed 3 mg/kg daily 1
• For dogs with cardiovascular comorbidities, start at a lower dose of 0.5 mg/kg daily and titrate more cautiously 1

Pre-treatment Assessment

• Perform cardiovascular examination before starting propranolol (auscultation, peripheral pulses, abdominal examination) 1, 2
• Check for contraindications including:
  • Heart block (second or third degree)
  • Decompensated heart failure
  • Hypotension
  • Hypersensitivity to propranolol 1, 2
• Consider baseline ECG and echocardiogram in dogs with suspected cardiac disease 1

Administration Guidelines

• Administer with food to reduce risk of gastrointestinal upset and hypoglycemia 1
• Hold doses during periods of reduced food intake or vomiting to prevent hypoglycemia 1
• Dose can be adjusted based on weight at follow-up visits 1

Monitoring

• Monitor heart rate and blood pressure at baseline and during dose adjustments 1, 2
• Follow-up evaluations every 2-3 months for stable patients 1
• Watch for common side effects including:
  • Bradycardia
  • Hypotension
  • Sleep disturbances
  • Peripheral vasoconstriction 2, 3

Treatment Duration

• Optimal duration is not well established for hemangiosarcoma 3, 4
• Consider long-term therapy as hemangiosarcoma is aggressive with high metastatic potential 4, 5
• Treatment can be stopped abruptly if necessary, though gradual tapering over 1-2 weeks may reduce risk of rebound tachycardia 1

Clinical Evidence in Vascular Tumors

• Propranolol has shown efficacy in human vascular tumors, particularly infantile hemangiomas at doses of 2-3 mg/kg/day 1, 6
• In human angiosarcoma, propranolol has been used at doses of 80-240 mg/day (approximately 1-3 mg/kg/day) 3, 4
• Propranolol's mechanism of action includes vasoconstriction, inhibition of angiogenesis, and induction of apoptosis in vascular tumor cells 4, 7

Important Considerations

• Propranolol may mask signs of hypoglycemia, which is particularly concerning in small or debilitated dogs 2
• Beta-blockers can worsen respiratory conditions; use with caution in dogs with concurrent respiratory disease 1, 2
• While evidence for propranolol in canine hemangiosarcoma is limited, its use is supported by data from human vascular tumors 4, 7
• Consider combination with standard chemotherapy protocols rather than monotherapy, as propranolol alone may have limited efficacy 4, 5