The effect of paclitaxel premedication discontinuation on rescue medication use

Premedication with clemastine and dexamethasone is administered to prevent paclitaxel-induced hypersensitivity reactions (HSRs), which predominantly occur during the first two administrations. To reduce premedication and related adverse effects, our hospital implemented a policy to discontinue premedication after two paclitaxel doses if no HSR occurred. This study evaluated whether rescue medication use after the second dose was not substantially higher following the protocol change.

We conducted a retrospective, observational, non-inferiority study, comparing patients receiving premedication for every paclitaxel administration (pre-policy change) with those discontinuing premedication after two HSR-free administrations (post-policy change). The primary outcome was the incidence of rescue medication use; non-inferiority was defined as the upper 95% confidence interval (CI) boundary below 4.0%.

A total of 148 patients were included (74 per group). Baseline characteristics were comparable between the two groups. Rescue medication was required in 3/74 patients (4.1%; 95% CI: 0.8-11.4%) in the pre-policy change group and 8/74 (10.8%; 95% CI: 4.8-20.2%) in the post-policy change group, yielding a difference of 6.8% (95% CI: - 1.6-15.1%). Non-inferiority could not be demonstrated, due to insufficient power resulting from an underestimated baseline incidence of rescue medication use. This limitation precludes interpreting the findings as evidence of inferiority.

Discontinuing premedication after two paclitaxel doses increased the incidence of rescue medication use, although reactions were mild and manageable, with most patients completing treatment. These findings suggest that premedication may not be necessary for all patients. Further research is needed to assess the safety of discontinuing premedication.