What is the recommended dosage and administration of Gemtasa (gemcitabine) for cancer treatment?

Gemcitabine (Gemtasa) Dosage and Administration for Cancer Treatment

The recommended dosage of gemcitabine for cancer treatment is 1000 mg/m² administered intravenously over 30 minutes on days 1,8, and 15 of each 28-day cycle when used as monotherapy, with specific modifications based on cancer type and combination regimens. 1

Cancer-Specific Dosing Regimens

Pancreatic Cancer

• Monotherapy: 1000 mg/m² IV over 30 minutes, weekly for 3 weeks every 28 days 2
• Fixed-dose rate option: 10 mg/m²/min (category 2B recommendation) as an alternative to standard 30-minute infusion 2
• Combination therapy with capecitabine: Gemcitabine 1000 mg/m² with capecitabine 1,660 mg/m²/day on days 1-21 every 4 weeks 2
• Combination with albumin-bound paclitaxel: 1000 mg/m² on days 1,8, and 15 of each 28-day cycle 3

Breast Cancer

• With paclitaxel: 1250 mg/m² IV over 30 minutes on days 1 and 8 of each 21-day cycle, following paclitaxel 175 mg/m² administered as a 3-hour IV infusion on day 1 1

Ovarian Cancer

• With carboplatin: 1000 mg/m² IV over 30 minutes on days 1 and 8 of each 21-day cycle, with carboplatin AUC 4 administered IV on day 1 after gemcitabine 1

Non-Small Cell Lung Cancer

• With cisplatin: 1000 mg/m² IV over 30 minutes on days 1,8, and 15 of each 28-day cycle in combination with cisplatin 100 mg/m² IV on day 1 1

Dose Modifications for Toxicity

Myelosuppression Management

• For ovarian cancer:

  • If ANC <500 × 10⁶/L for >5 days or <100 × 10⁶/L for >3 days, or febrile neutropenia, or platelets <25,000 × 10⁶/L: Reduce dose to 800 mg/m² on days 1 and 8 1
  • For subsequent occurrences: Further reduce to 800 mg/m² on day 1 only 1

• For breast cancer (day 8 modifications):

  • ANC 1000-1199 × 10⁶/L or platelets 50,000-75,000 × 10⁶/L: Give 75% of full dose
  • ANC 700-999 × 10⁶/L and platelets ≥50,000 × 10⁶/L: Give 50% of full dose
  • ANC <700 × 10⁶/L or platelets <50,000 × 10⁶/L: Hold treatment 1

Performance Status Considerations

• For patients with good performance status (ECOG 0-1): Full-dose gemcitabine or combination regimens are recommended 2
• For patients with poor performance status (ECOG ≥2):
  • Consider gemcitabine monotherapy at 1000 mg/m² over 30 minutes, weekly for 3 weeks every 28 days 2
  • Fixed-dose-rate gemcitabine (10 mg/m²/min) may substitute for standard infusion (category 2B) 2

Administration Considerations

• Administer as an intravenous infusion over 30 minutes
• When used in combination therapy, follow specific sequence requirements:
  • In breast cancer: Administer after paclitaxel on day 1 1
  • In ovarian cancer: Administer before carboplatin on day 1 1

Safety Profile

Gemcitabine has a relatively mild toxicity profile compared to many other chemotherapeutic agents, with the most common adverse effects being:

• Myelosuppression (primarily neutropenia)
• Mild nausea and vomiting
• Transient elevations in liver enzymes
• Flu-like symptoms 4

The favorable tolerability profile makes gemcitabine an appropriate option for patients who may not tolerate more aggressive regimens, particularly those with advanced disease or poor performance status.