Risk Evaluation of Proton Pump Inhibitors for Panitumumab-Related Hypomagnesemia in Patients with Metastatic Colorectal Cancer.

Hypomagnesemia commonly occurs as a side effect of panitumumab treatment. In severe cases, temporary discontinuation or dose reduction of panitumumab may be necessary. Proton pump inhibitors (PPIs) are reportedly potential risk factors for hypomagnesemia. We conducted a multicenter study to assess the impact of PPIs on the risk of grade 3-4 hypomagnesemia in patients with metastatic colorectal cancer (mCRC) receiving panitumumab. We adjusted for potential bias using a propensity score-matched analysis and retrospectively reviewed the medical records of patients. Hypomagnesemia severity was graded according to the Common Terminology Criteria for Adverse Events, version 5.0. A total of 165 patients were enrolled in this study. The incidence of grade 3-4 hypomagnesemia was significantly higher in the PPI group than in the non-PPI group, both before (20.0% [30/60] vs. 8.0% [8/105], p = 0.026) and after propensity score matching (16.2% [6/37] vs. 0% [0/37], p = 0.025). In the propensity score-matched cohort, the risk of grade 3-4 hypomagnesemia was significantly higher in the PPI group (odds ratio, 2.19; 95% confidence interval, 1.69-2.84; p = 0.025). These findings suggest that concomitant use of PPIs significantly increases the risk of grade 3-4 hypomagnesemia in patients with mCRC receiving panitumumab. Therefore, close monitoring of these patients is imperative.

[Investigation for relation of gustatory and olfactory impairment in patients receiving cancer chemotherapy].

Because it is considered that there is a close connection between gustation and olfactation, and that a decline in the function of either sensation influences the other one, it would be useful to clarify the relation between gustatory and olfactory disorders in patients receiving cancer chemotherapy. Therefore, we investigated the frequency of gustatory and olfactory disorders in patients administered anticancer drugs at the Division of Outpatient Chemotherapy of Kanazawa University. Among 136 patients who consented to participate in the investigation, 75 patients (55%) complained of a gustatory disorder, and 26 patients (19%) complained of an olfactory disorder. The occurrences of olfactory disorder were significantly greater in patients who had gustatory disorder than in patients who did not. The expression frequency of gustatory disorders was significantly higher among those taking docetaxel (85%) when compared with patients on other regimens. Although not statistically significant, the incidence of olfactory disorder was higher in patients taking docetaxel (31%), irinotecan+l-leucovorin (l-LV)+5-fluorouracil (5-FU) (31%), l-oxaliplatin+l-LV+5-FU (28%), trastuzumab (23%), and weekly paclitaxel (22%). Medical staff should recognize that olfactory disorders are similar to gustatory disorders, as they both have adverse reactions induced by anticancer drugs.