What are the doses of AC (Adriamycin (doxorubicin) and Cyclophosphamide) chemotherapy for a patient who is 170 cm tall and weighs 84 kg?

AC Chemotherapy Dosing for a Patient with Height 170 cm and Weight 84 kg

For a patient with height 170 cm and weight 84 kg, the recommended doses for AC chemotherapy are doxorubicin 60 mg/m² and cyclophosphamide 600 mg/m² based on actual body weight, calculated using body surface area (BSA). 1, 2

Calculating the Dose

1. First, calculate the patient's BSA using standard formula:

   • BSA = √[(Height in cm × Weight in kg)/3600]
   • BSA = √[(170 × 84)/3600]
   • BSA = √(14,280/3600)
   • BSA = √3.97
   • BSA = 1.99 m²

2. Calculate the doses:

   • Doxorubicin: 60 mg/m² × 1.99 m² = 119.4 mg (round to 119 mg)
   • Cyclophosphamide: 600 mg/m² × 1.99 m² = 1,194 mg (round to 1,194 mg)

Important Considerations

Dosing Guidelines

• The American Society of Clinical Oncology (ASCO) recommends using actual body weight for calculating chemotherapy doses regardless of obesity status 2
• There is no evidence that full weight-based dosing increases toxicity in obese patients 2
• Reducing doses based on weight alone may compromise treatment efficacy and negatively impact survival outcomes 2

Administration Schedule

• Standard AC regimen is administered intravenously on day 1 of a 21-day cycle for a total of 4 cycles 1
• Dose-dense regimen (every 14 days) requires mandatory G-CSF support but is not specified in your question 1

Supportive Care

• Antiemetic prophylaxis is essential as AC is highly emetogenic:
  • Recommended combination: 5-HT3 antagonist + dexamethasone + NK1 receptor antagonist 1
  • When using aprepitant, reduce dexamethasone dose due to drug interactions 1

Monitoring

• Monitor for neutropenia, with fever requiring immediate evaluation 1
• Assess left ventricular ejection fraction (LVEF) before starting treatment due to potential cardiotoxicity of doxorubicin 1

Common Pitfalls to Avoid

1. Arbitrary dose capping: Avoid arbitrarily capping doses based on BSA or weight alone. This practice can lead to suboptimal outcomes 2

2. Dose reduction without clinical indication: Do not reduce doses based solely on age or weight without specific clinical indications such as organ dysfunction or poor performance status 2

3. Incorrect BSA calculation: Using ideal body weight instead of actual body weight for BSA calculation can lead to underdosing 2

4. Ignoring supportive care: Failure to provide appropriate antiemetic prophylaxis can lead to poor tolerance and potential treatment interruptions 1

By following these evidence-based recommendations for dosing AC chemotherapy, you can optimize treatment outcomes while maintaining an acceptable safety profile for your patient.