Improved Outcome with Chronic Subcutaneous Infusion of Ondansetron for Intractable Nausea and Vomiting
Macario, Alex MD, MBA; Ronquillo, Ricardo B. MD; Brose, William G. MD; Gaeta, Raymond R. MD
Department of Anesthesia, Stanford University School of Medicine, Stanford, CA 94305-5115.
To the Editor:
We report the delivery of subcutaneous (SC) ondansetron over a period of five months in an otherwise healthy 37-year-old Caucasian female with neuropathic right arm pain associated with persistent nausea and vomiting. Previous antiemetic therapy consisting of antihistamines, phenothiazines, butyrophenones, and benzamides had failed; the patient had required increasing nursing and emergency room services with four inpatient hospitalizations in a nine-month period for right arm pain and dehydration.
We initiated intravenous and then SC dosing of ondansetron and morphine titrated to patient pain and nausea reports. She was discharged from the hospital receiving ondansetron (1.25 mg/h [2 mg/mL]) delivered SC via a Computerized Ambulatory Drug Delivery pump (Pharmacia Deltec, St. Paul, MN). The patient adjusted the ondansetron infusion as necessary to attain acceptable relief of nausea and vomiting.
Ondansetron is formulated as a sterile, aqueous isotonic solution buffered with citrate and is not recommended for SC administration by the manufacturer due to its low pH (3.5) . No allergic or toxic reactions were detected in this patient despite the acidic pH. This may be due to the slow rate of infusion. The patient did not develop known side effects of ondansetron such as extrapyramidal symptoms, headache, hypersensitivity reaction, or xerostomia. Laboratory tests showed normal liver enzyme levels. The patient did not develop clinically significant erythema or induration at the infusion sites. The average daily SC ondansetron requirement of 23 mg for this patient approximates the recommended intravenous ondansetron dosage for cancer chemotherapy of either a single 32-mg dose or three 0.15-mg/kg doses . The patient's other regular pharmacologic therapy for nausea and vomiting includes a scopolamine patch every three days.
In the five months after institution of the SC ondansetron delivery system, the patient reported decreased nausea resulting in 1) increased satisfaction (visual analog score increase from 6/10 to 8/10) with medical therapy and 2) improvements in quality of health-related life due to an increased ability to complete household chores and more frequent social activities. The patient did not require inpatient care or emergency room services after initiation of the SC drug delivery. The long-term plan is to increase opioid-free intervals and to reduce the patient's dependence on ondansetron while maintaining improvements in function and quality of life. This patient provides evidence of safety for long-term (five-month) infusion of SC ondansetron for the management of chronic nausea and vomiting.
Alex Macario, MD, MBA
Ricardo B. Ronquillo, MD
William G. Brose, MD
Raymond R. Gaeta, MD
Department of Anesthesia
Stanford University School of Medicine
Stanford, CA 94305-5115
© 1996 International Anesthesia Research Society
1. Physicians' Desk Reference. 48th ed. Montvale, NJ: Medical Economics Data Production Company, 1994:795.