Background: Ranitidine is prescribed, with other pre-medications, in paclitaxel-containing protocols as prophylaxis for hypersensitivity reactions (HSRs).1-3 A metropolitan hospital omitted ranitidine from paclitaxel-containing protocols, following a ranitidine shortage due to contamination with the cancer-causing impurity N-nitrosodimethylamine.4 It is unknown if omitting ranitidine affects the incidence and severity of HSRs in practice.
Aim: To determine if prophylaxis of HSRs without ranitidine increases the incidence and severity of HSRs in patients receiving treatment with intravenous paclitaxel-containing protocols for head and neck, breast or lung cancer.
Method: The pharmacy oncology information management system CHARMTM and integrated electronic Medical Record (ieMR) were used to retrospectively compare the incidence and severity of intravenous paclitaxel-induced HSRs in 40 patients who received ranitidine pre-shortage (ranitidine group) and 40 patients who did not receive ranitidine post-shortage (nil-ranitidine group). Head and neck, breast and lung cancer protocols were included. Common Terminology Criteria for Adverse Events was used to grade severity of the HSRs if not already noted in a patient’s medical record. Identified HSRs were cross-checked with reported HSRs in the incident reporting system RiskMan for the same time period.
Results: More patients in the ranitidine group (22.5%) experienced HSRs compared to those in the nil-ranitidine group (15%). In the ranitidine group, the incidence of HSRs was 4.56% (11 HSRs occurred from 241 doses) and the severity of HSRs was: 1 Grade 1 reaction, 9 Grade 2 reactions and 1 Grade 4 reaction. In the nil-ranitidine group, the incidence of HSRs was 2.21% (6 HSRs occurred from 271 doses) and the severity of HSRs was: 1 Grade 1 reaction and 5 Grade 2 reactions. Only 45% and 17% of HSRs in the ranitidine group and nil-ranitidine group, respectively, were reported in RiskMan.
Conclusions: Omitting ranitidine from intravenous paclitaxel-containing protocols did not increase the incidence or severity of HSRs. A larger retrospective study is recommended to inform paclitaxel protocol updates, in line with quality use of medicines principles, should the ranitidine shortage be resolved. HSRs were recorded in the incident reporting system RiskMan less than half the time for both groups. Identification of barriers to staff using RiskMan to report HSRs is required to improve reporting uptake, and therefore accuracy of data.