Interference by pralidoxime (PAM) salts in clinical laboratory tests

Evaluation of Linearity and Interference Effect on SMBG and POCT Devices, Showing Drastic High Values, Low Values, or Error Messages

BACKGROUND

When a patient with diabetes measures blood glucose levels using a simple blood glucose meter, an error message or abnormal value may be displayed because of interfering substances, potentially leading to unnecessary medical treatment.

METHODS

Here, we tested 10 self-monitoring of blood glucose (SMBG) and point-of-care testing (POCT) devices to investigate under what conditions they fail to measure blood glucose levels or display abnormal values instead. We also evaluated the influence and linearity of several well-known interfering substances and hematocrit (Ht). Each adjusted sample was measured by each device twice and the values compared with the reference values.

RESULTS

Linearity was favorable in all but one model. The impact of the interfering substances and Ht has been confirmed in many SMBG and POCT devices. In particular, some models showed significant pseudo-high or -low levels for samples that contained ascorbic acid, which is used widely in infusion solutions. Three devices showed error messages to avoid presenting a false value.

CONCLUSIONS

Since pseudo-high levels may result in the excessive administration of insulin and lead to adverse events, this report serves as a critical reminder of the importance of device choice for specific indications. Three new devices have safety functions that prevent the showing of false values.

Photoinduced electron transfer between quantum dots and pralidoxime: an efficient sensing strategy

Photoinduced electron transfer (PET)-mediated fluorescence quenching of CdTe/CdS quantum dots by pralidoxime (PAM).

FDA-approved drugs that interfere with laboratory tests: A systematic search of US drug labels

Drug-related laboratory test interference or drug/laboratory test interactions (DLTI) are a major source of laboratory errors. DLTI is of concern with regard to both the clinical diagnosis and the monitoring of patients. Although there have been numerous reports about specific drugs that interfere with laboratory tests, there has not been a recent review on the topic. We herein provide a review of the known DLTI of US FDA-approved drugs based on a systematic search of DailyMed, a website containing the labels of US FDA-approved drugs. The labels for all human single-ingredient prescription drugs included in the database (1368) were searched using stemmed keywords and were manually reviewed for their relevance to DLTI. A total of 134 labels were positive, which indicated that the drug interferes with at least one clinical laboratory test. Antibacterial agents, psychotropic drugs and contrast media are the classes of drugs most likely to lead to DLTI. Urine was the clinical sample most frequently affected by DLTI. The FDA drug label is a source of information for studies of DLTI, although information is still lacking for most drugs, and additional improvements are needed for many of the existing records. Medical professionals, clinicians and laboratory staff should keep these possible interactions in mind when interpreting the results of laboratory tests, and should ensure that they obtain a complete and accurate record of all drugs being used by patients in order to anticipate potential DLTI. The development of a reporting system to address potential DLTI is warranted.