Drug stability and compatibility in oncology care

Infusional chemotherapy has been increasingly used based upon the fact that most drugs have a relatively short half-life following bolus exposure, and increasing the available drug concentration over time may maximize the antitumor effect. As a practical matter, the application of infusional chemotherapy especially in an ambulatory setting, absolutely requires that the individual antineoplastic agents be stable in solution at room temperature (or at body temperature for implanted pump systems) and that the drugs in the infusion (including antiemetics) be compatible. The capacity to mix antineoplastic agents and antiemetics (also colony-stimulating factors) in a single solution facilitates infusional combination chemotherapy. Technologic advances are on the horizon which will provide the capability of administration of multiple drugs through a single access site to allow one to utilize a single delivery source obviating the need for admixtures of drugs. However, in the interim, admixtures represent the optimal method for the delivery of multi-agent chemotherapy in the setting in which continuous infusional drug delivery for 24 hours or more is employed. The goal of continuous infusion cancer chemotherapy is to ensure delivery of an unaltered cytotoxic drug, avoiding situations that could affect the stability of the infusion admixture. With cancer chemotherapy infusion therapy being administered through oncology clinics without the benefits of a pharmacist, the nurse plays a pivotal role in the preparation of the infusion, supervision of the patient, and when applicable in providing counseling on the proper storage, handling of the cytotoxic drugs, and disposal of contaminated infusion materials. Thus, by optimizing the integrity of the chemotherapeutic infusion, the patient achieves maximum benefits of cancer chemotherapy and the level of success anticipated with oncology care. The nurse may also be involved with clinical studies involving the preparation of other combinations of infusional chemotherapy including antiemetics and colony-stimulating factors, requiring integrity of the infusion to incompatibility and instability. In order to avoid failure of the infusion through improper preparation or reconstitution of the infusion or improper storage conditions and the resulting unnecessary waste and disposal expenses, the nurse needs to be fully aware of the factors affecting the stability and compatibility of the infusion and to interact with other health professionals and the literature for the critical information related to maintaining the integrity of the cancer chemotherapy infusion. "Good intentions without good communication equals potential disaster."