[Effects of Serum Sodium Concentrations on Nausea and Vomiting after Moderately Emetogenic Chemotherapy].

Chemotherapy-induced nausea and vomiting (CINV) is the most unbearable adverse effect of chemotherapy. The antiemesis guidelines of the National Comprehensive Cancer Network indicate that hyponatremia is a risk factor for CINV, although the relationship between the incidence of CINV and hyponatremia has not been sufficiently studied. This two-center prospective observational study evaluated whether low serum sodium concentrations were a risk factor for CINV. The study included 34 patients who were scheduled to receive first-line carboplatin- or oxaliplatin-based chemotherapy for gynecological or colorectal cancers. Patient diaries were used to record the daily incidences of CINV events during a 5-day period. The patients were divided based on the median serum sodium concentration into a low Na+ group (<141 mEq/L) and a high Na+ group (≥141 mEq/L). The incidences of delayed nausea were 27.8% in the high Na+ group and 62.5% in the low Na+ group (p=0.042), with complete control rates (no vomiting, rescue medication, or grade 2 nausea) of 77.8% and 43.8%, respectively (p=0.042). The time to complete control failure in each group was analyzed using the Kaplan-Meier method, which revealed a significantly shorter time in the low Na+ group (p=0.03). Therefore, these results indicate that low serum sodium concentrations may increase the risk of CINV.

[Study of the serum concentrations of acetaminophen overdose].

Acetaminophen (APAP) is a commonly used nonsteroidal analgesic because it is considered safe. However, APAP is a major cause of acute poisoning because of its easy availability. APAP overdose causes hepatic failure. A previous study reported a case of death occurring 3-4 days after APAP overdose. Serum APAP level is an index for administration of N-acetyl-L-cysteine (NAC). We investigated cases of APAP overdose to determine the correlation between serum APAP level and estimated APAP dosage, NAC medication, hepatic failure, etc. In one case, we found that the use of estimated APAP dosage alone led to inappropriate NAC medication. Moreover, there were cases in which serum APAP level increased 4 hr after APAP overdose. Repeated cases of APAP overdose suggested that the presence of NAC medication caused a difference in liver function test values.

In vitro study of the adsorption characteristics of drugs.

The adsorption characteristics of eight adsorbents, cholestyramine, colestimide, aluminum silicate, sucralfate, aluminum hydroxide, calcium polystyrene sulfonate, carbon sphere and medicinal carbon, on the drugs such as methotrexate, antidepressants, mizoribine and ciprofloxacin hydrochloride were investigated in vitro. Medicinal carbon showed an excellent adsorption of all the tested drugs while the carbon spheres showed a high but slow adsorption characteristic. Cholestyramine and colestimide showed a higher adsorption in methotrexate than the other adsorbents. Aluminum silicate and calcium polystyrene sulfonate showed higher adsorption in four antidepressants, clomipramine hydrochloride, imipramine hydrochloride, mianserin hydrochloride and trazodone hydrochloride. In mizoribine, there were no adsorbents that showed higher adsorption except for the medicinal carbon. In ciprofloxacin hydrochloride, aluminum preparations and calcium polystyrene sulfonate showed higher adsorption characteristics. It is suggested that several adsorbents are potentially useful treatments for drug overdoses, but that these adsorbents have the possibility of decreasing the effects of the co-administered medicines.