Establishing a baseline incidence of adverse drug reactions in hospitalised oncology patients

Abstract

Objectives. To establish the incidence of adverse drug reactions (ADRs) in oncology patients hospitalised at a tertiary referral adult cancer hospital and identify areas where intervention strategies may effectively reduce their impact. Design. A prospective study was conducted in November and December 1998 at the Peter MacCallum Cancer Institute (PMCI), Melbourne, Australia. Pharmacists identified patients who had experienced an ADR contributing to the admission or occurring during the episode of care. Outcome measures. An assessment was made of causality, as definite, probably or possibly. The severity of the ADR was assessed as mild, moderate or severe. Results. Twenty-six admissions (9.6%) were related to drug therapy. One hundred and thirty-four ADRs occurred in 86 inpatient episodes of care (31.6% of admissions). One hundred and four ADRs (60.8%) were associated with active therapy for malignancy or infection. Supportive therapy, including analgesics and antiemetics, were implicated in 67 (39.2%) adverse events. Pharmacists rated the majority of reactions as definitely associated with the implicated drug and the majority of at least moderate severity. Discussion. Drug therapy contributed to 9.6% of admissions. This is higher than in other Australian studies. The majority of ADRs identified were associated with active therapy for malignancy or infection. These adverse effects are not unexpected in the setting of aggressive therapy. Other potentially preventable ADRs may be overlooked in the context of the more severe and life-threatening events occurring simultaneously. Conclusion. Approximately 37.5% of patients admitted to PMCI experienced an ADR. Many of these events may have been prevented using simple intervention strategies. There is an opportunity for clinical pharmacists to ensure preventive measures are instituted, thereby improving patient outcomes.