Objective: to evaluate the bioavailability of subcutaneous granisetron.Patients receiving platinum-based chemotherapy will be randomized to receive granisetron 3 mg either subcutaneously or intravenously in a crossover manner during two cycles. Blood and urine samples will be collected after each cycle.

5-HT3 antagonists are one of the mainstays of antiemetic treatment and they are administered either intravenously or orally. Nevertheless sometimes neither administration route is feasible, such as in patients unable to admit oral intake managed in an outpatient setting. Our objective is to evaluate the bioavailability of subcutaneous granisetron.Patients receiving platinum-based chemotherapy will be randomized to receive granisetron 3 mg either subcutaneously or intravenously in a crossover manner during two cycles. Blood and urine samples will be collected after each cycle. Pharmacokinetics of SC and IV granisetron will be prospectively compared.

Inclusion Criteria:

• Cancer patients receiving platinum-based chemotherapy
• adequate bone marrow, hepatic and renal function, respectively defined by: platelets >100000/mm3 and absolute neutrophil count >1500/mm3; bilirubin, AST and ALT <2 times x upper limit of normality; and creatinine <1.5 mg/dl.
• ECOG performance status <2 and body mass index from 20-28 kg/m2.

Exclusion Criteria:

• Pregnancy
• Serious concomitant diseases, in the invesgator´s criteria