(P-267) Excess Risk of Anaphylaxis with Concomitant Use of Qingkailing Injection and Cefotaxime Sodium: An Example of Novel Herbal-drug Interaction

Background: There have been studies warned of potential interactions between herbal products and conventional drugs but little is known about the actual interacting effect of specific herbal-drug combinations. The need for detecting unknown DDIs between conventional drugs and herbal medicines are urgent.

Objectives: Examine the change of risk of anaphylaxis when cefotaxime sodium was used concomitantly with a widely used herbal injection (qingkailing) by retrospective analysis of a spontaneous reporting system.

Methods: Data were collected during 2005-2014 from China Guangdong Provincial Center of ADR Monitoring. Reporting odds ratios (RORs) were used as a measure of disproportionality and were adjusted for age and gender. An observed-to-expected ratio Ω was also used for interaction detection.

Results: The adjusted RORs (95% CIs) for anaphylaxis in patients who used qingkailing injection or cefotaxime sodium alone and those who used both drugs concomitantly compared with patients who used neither of the two drugs were 1.50 (1.38-1.64), 1.60 (1.45-1.76) and 9.32 (3.49-24.85), respectively. The measured Ω, Ω0, Ω025 and Ω975 was 1.81, 2.15, 0.44 and 2.74, respectively.

Conclusions: The results suggested that concomitant use of qingkailing injection and cefotaxime sodium may have harmful interacting effect and generate excess risk of anaphylaxis. Because of a series of shortcomings of SRS databases the results should be treated as a possible interaction signal and need to be tested by different approaches.