For the first-line treatment of patients with metastatic breast cancer, locally advanced (Stage IIIA or IIIB), or metastatic (Stage IV) non-small cell lung cancer and as first-line treatment for patients with adenocarcinoma of the pancreas.
Gemcitabine inhibits thymidylate synthetase, leading to inhibition of DNA synthesis and cell death. Gemcitabine is a prodrug so activity occurs as a result of intracellular conversion to two active metabolites, gemcitabine diphosphate and gemcitabine triphosphate by deoxycitidine kinase. Gemcitabine diphosphate also inhibits ribonucleotide reductase, the enzyme responsible for catalyzing synthesis of deoxynucleoside triphosphates required for DNA synthesis. Finally, Gemcitabine triphosphate (diflurorodeoxycytidine triphosphate) competes with endogenous deoxynucleoside triphosphates for incorporation into DNA.
Myelosuppression, paresthesias, and severe rash were the principal toxicities, LD<sub>50</sub>=500 mg/kg (orally in mice and rats)
100%
Short infusions ranged from 32 to 94 minutes, and the value for long infusions vary from 245 to 638 minutes, depending on age and gender.
* 50 L/m^2 [infusions lasting <70 minutes] * 370 L/m^2 [long infusions]
* 92.2 L/hr/m2 [Men 29 yrs] * 75.7 L/hr/m2 [Men 45 yrs] * 55.1 L/hr/m2 [Men 65 yrs] * 40.7 L/hr/m2 [Men 79 yrs] * 69.4 L/hr/m2 [Women 29 yrs] * 57 L/hr/m2 [Women 45 yrs] * 41.5 L/hr/m2 [Women 65 yrs] * 30.7 L/hr/m2 [Women 79 yrs]