Can emergency department clinicians diagnose gamma-hydroxybutyrate (GHB) intoxication based on clinical observations alone?

OBJECTIVES: Gamma-hydroxybutyrate (GHB) is a drug of abuse with central depressing effects, which may cause coma with a GCS score as low as 3. A rapid diagnosis 'GHB intoxication' may prevent unnecessary diagnostic work-up and may lead to guided, less invasive, treatment. The aim of this study was to evaluate if ED physicians' clinical evaluation were sufficient for diagnosis in patients with suspected GHB-intoxication. METHODS: Patients presenting at the ED with a GCS<15 and a potential intoxication with drugs of abuse for whom urine toxicology screen was performed were included consecutively. After a first assessment, the ED physician registered the most likely initial diagnosis in the hospital information system. Urine of these patients was tested with a validated gas chromatography analytical method for GHB (confirmation test). The initial diagnoses were compared for agreement with the results of the confirmation test. RESULTS: A total of 506 patients were included, 100 patients tested positive for GHB and 406 patients tested negative for GHB. Sensitivity and specificity of the ED physicians compared with the confirmation test to diagnose GHB intoxications were 63% (95% CI 52 to 73) and 93% (95% CI 90 to 95), respectively. The positive predictive value was 67% (95% CI 60 to 77) and the negative predictive value was 92% (95% CI 88 to 94). CONCLUSION: Physicians underestimate the presence of GHB intoxication and can fail to diagnose GHB intoxication based on clinical observations alone. In the future, a rapid reliable initial analytical GHB test in addition to clinical judgement could be valuable to reduce false negative diagnosis.

Drug-drug interactions of cytostatics with regular medicines in lung cancer patients.

Background Lung cancer patients have a high risk for drug-drug interactions, as they use numerous types of concomitant medicines including antineoplastic agents, cancer treatment co-medication, and medicines aimed at several types of comorbidities. Objective The primary objective of this study is to determine the incidence and the clinical relevance of the drug-drug interactions between antineoplastic agents and regular medication used by lung cancer patients. Secondary objectives are (i) to determine the effectiveness of the medication review by the hospital pharmacists concerned, (ii) to establish which patients are most at risk of drug-drug interactions and (iii) to determine whether physicians comply with advice given by hospital pharmacists. Setting This prospective study was undertaken in a Dutch hospital pharmacy, at Onze Lieve Vrouwe Gasthuis (OLVG), Amsterdam. Methods All lung cancer patients receiving one or more cytotoxic agents during the period 21 June 2010 till 2 December 2014 at OLVG were included. The medication list of the patients was obtained electronically from the community pharmacy and checked for interactions by a hospital pharmacist. Interactions that required intervention according to the national database were the only ones taken into account. Interventions were recorded in the patients' electronic charts. All medication reviews were cross-checked and analyzed by an independent pharmacist at the end of the study period. Main outcome measure Prevalence and clinical relevance of drug-drug interactions between antineoplastic agents and other types of medication in lung cancer patients. Results A total of 298 lung cancer patients were included in this study. In 53 patients (18%), a total of 73 interactions with potential clinical relevance were found. The most frequent interaction was between cytostatics and coumarins while the most relevant one was between cisplatin and furosemide. According to statistical analysis, gender as well as the number of drugs prescribed were significant predictors for drug-drug interactions. Eighty-four percent of the interactions were discovered by pharmacists during daily routine. In 92% of the cases, the pulmonary physicians complied with the advice of the pharmacist. Conclusion Eighteen percent of lung cancer patients treated with cytotoxic therapy had one or more relevant drug-drug interactions. This study shows that medication surveillance by a hospital pharmacist is necessary to prevent possible negative drug-drug interactions. Further research should focus on the clinical outcome of the interactions as well as on interactions between cytostatics and alternative medicines and/or over-the-counter medicines.