Intraperitoneal chemotherapy with melphalan.

We administered melphalan by the intraperitoneal route to investigate its toxicity and pharmacokinetics. The drug was instilled with 2 litres of fluid and allowed to dwell in the peritoneal cavity for 4 hours. No local toxicity was detected by clinical examination, laboratory tests, or histologic examination. The intraperitoneal route allowed the dose to be increased to approximately three times the maximum dose tolerated intravenously before drug leaking into the systemic circulation produced dose-limiting myelosuppression. The peak peritoneal concentration averaged 93-fold greater than the plasma concentration, and total drug exposure for the peritoneal cavity averaged 63-fold greater than that for plasma. Tumor regressions were observed in patients with ovarian carcinoma and gastrointestinal adenocarcinomas. This study shows that from the pharmacologic point of view, if any portion of the tumor can be reached by intraperitoneal instillation, then there is a very strong rationale for the administration of melphalan by the intraperitoneal route, rather than the oral or intravenous route, for the treatment of tumors confined to the peritoneal cavity.