Harald Dormann

The Impact of Unlicensed and Off-Label Drug Use on Adverse Drug Reactions in Paediatric Patients

AbstractBackground and objective: Many drugs that are used to treat children are either not licensed for use in paediatric patients (unlicensed) or prescribed outside the terms of the product licence (off label). The incidence of adverse drug reactions (ADRs) associated with the use of such drugs is yet to be established. This study investigates, for the first time in a German patient population, the impact of unlicensed and off-label drug use on ADRs in paediatric patients. Patients and methods: An 8-month prospective pharmacoepidemiological cohort-based survey was conducted on a ten-bed paediatric isolation ward at the University Hospital Erlangen-Nüremberg, Germany. All patients were intensively monitored for ADRs by a pharmacoepidemiological team. ADRs were characterised according to international classification methods. All drug prescriptions were evaluated retrospectively as to unlicensed or off-label use on the basis of the product information. Results: A total of 178 patients were included in the study and 740 drug prescriptions were given to 156 patients (median three prescriptions per patient). In 198 cases (27.7% of all prescriptions) drugs were used in either an unlicensed (n = 3) or off-label (n = 195) manner. A total of 46 ADRs were observed in 31 patients (17.4%). Patients receiving at least one unlicensed or off-label drug prescription during hospitalisation (n = 92) experienced an ADR significantly more frequently (n = 26 patients) than patients receiving only licensed drugs (n = 64 vs 5 patients). ADRs were associated with 29 (5.6%) of the 517 licensed drug prescriptions and with 12 (6.1%) of the 198 unlicensed or off-label drug prescriptions. The majority of ADRs caused by unlicensed and off-label drug use were recognised by the attending physician. However, statistical analysis revealed no significant difference in the number of licensed and unlicensed/off-label drug prescriptions causing ADRs. Conclusion: This study demonstrated that at a paediatric isolation ward the incidence of ADRs caused by unlicensed or off-label drug use was not significantly more than that caused by the licensed drug use. However, patients treated with unlicensed or off-label drugs were shown to possess a significantly increased risk for developing ADRs.

Incidence and costs of adverse drug reactions during hospitalisation: computerised monitoring versus stimulated spontaneous reporting.

AbstractObjective: To implement a computer-based adverse drug reaction monitoring system and compare its results with those of stimulated spontaneous reporting, and to assess the excess lengths of stay and costs of patients with verified adverse drug reactions. Design: A prospective cohort study was used to assess the efficacy of computer-based monitoring, and case-matching was used to assess excess length of stay and costs. Setting: This was a study of all patients admitted to a medical ward of a university hospital in Germany between June and December 1997. Patients and participants: 379 patients were included, most of whom had infectious, gastrointestinal or liver diseases, or sleep apnoea syndrome. Patients admitted because of adverse drug reactions were excluded. Methods: All automatically generated laboratory signals and reports were evaluated by a team consisting of a clinical pharmacologist, a clinician and a pharmacist for their likelihood of being an adverse drug reaction. They were classified by severity and causality. For verified adverse drug reactions, control patients with similar primary diagnosis, age, gender and time of admission but without adverse drug reactions were matched to the cases in order to assess the excess length of hospitalisation caused by an adverse drug reaction. Results: Adverse drug reactions were detected in 12% of patients by the computer-based monitoring system and stimulated spontaneous reporting together (46 adverse reactions in 45 patients) during 1718 treatment days. Computer-based monitoring identified adverse drug reactions in 34 cases, and stimulated spontaneous reporting in 17 cases. Only 5 adverse drug reactions were detected by both methods. The relative sensitivity of computer-based monitoring was 74% (relative specificity 75%), and that of stimulated spontaneous reporting was 37% (relative specificity 98%). All 3 serious adverse drug reactions were detected by computer-based monitoring, but only 2 out of the 3 were detected by stimulated spontaneous reporting. The percentage of automatically generated laboratory signals associated with an adverse drug reaction (positive predictive value) was 13%. The mean excess length of stay was 3.5 days per adverse drug reaction. 48% of adverse reactions were predictable and detected solely by computer-based monitoring. Therefore, the potential for savings on this ward from the introduction of computer-based monitoring can be calculated as EUR56 200/year (

Readmissions and adverse drug reactions in internal medicine: the economic impact

US59 600/year) [1999 values]. Conclusion: Computer monitoring is an effective method for improving the detection of adverse drug reactions in inpatients. The excess length of stay and costs caused by adverse drug reactions are substantial and might be considerably reduced by earlier detection.

Women encounter ADRs more often than do men

Background.  Recent studies show that nearly half of the hospitalized patients are readmitted within 6 months from discharge. No data exist about the relationship between adverse drug reactions (ADRs) and readmittance to a department of internal medicine.

Role of P-Glycoprotein Inhibition for Drug Interactions : Evidence from In Vitro and Pharmacoepidemiological Studies

BackgroundSeveral publications indicate that the female gender experiences a higher incidence of adverse drug reactions (ADRs) than does the male gender. The reasons, however, remain unclear. Gender-specific differences in the pharmacokinetic and pharmacodynamic behaviour of drugs could not be identified as an explanation. The aim of this study was to analyse ADR risk with respect to gender, age and number of prescribed drugs.MethodsA prospective multicenter study based on intensive pharmacovigilance was conducted. Information on patient characteristics and evaluated ADRs was stored in a pharmacovigilance database—KLASSE.ResultsIn 2,371 patients (1,012 female subjects), 25,532 drugs were prescribed. In 782 patients, at least one ADR was found. A multivariate regression analysis adjusting for age, body mass index (BMI) and number of prescribed drugs showed a significant influence of female gender on the risk of encountering ADRs [odds ratio (OR) 1.596, confidence interval (CI) 1.31–1.94; p < 0.0001). Dose-related ADRs (51.8%) were the dominant type in female subjects. Comparing system organ classes of the World Health Organisation (SOC-WHO), cardiovascular (CV) ADRs were particularly frequent in female subjects (OR 1.92, CI 1.15–3.19; p = 0.012).ConclusionOur data confirm the higher risk of ADRs among female subjects compared with a male cohort. Several explanations were investigated. No single risk factor could be identified.

Identification of Adverse Drug Reactions in Geriatric Inpatients Using a Computerised Drug Database

ObjectivesWe determined in vitro the potency of macrolides as P-glycoprotein inhibitors and tested in hospitalised patients whether coadministration of P-glycoprotein inhibitors leads to increased serum concentrations of the P-glycoprotein substrates digoxin and digitoxin.MethodsIn vitro, the effect of macrolides on polarised P-glycoprotein-mediated digoxin transport was investigated in Caco-2 cells. In a pharmacoepidemiological study, we analysed the serum digoxin and digitoxin concentrations with and without coadministration of P-glycoprotein inhibitors in hospitalised patients.ResultsAll macrolides inhibited P-glycoprotein-mediated digoxin transport, with concentrations producing 50% inhibition (IC50) values of 1.8, 4.1, 15.4, 21.8 and 22.7 μmol/L for telithromycin, clarithromycin, roxithromycin, azithromycin and erythromycin, respectively. Coadministration of P-glycoprotein inhibitors was associated with increased serum concentrations of digoxin (1.3 ± 0.6 vs 0.9 ± 0.5 ng/mL, p < 0.01). Moreover, patients receiving macrolides had higher serum concentrations of cardiac glycosides (p < 0.05).ConclusionMacrolides are potent inhibitors of P-glycoprotein. Drug interactions between P-glycoprotein inhibitors and substrates are likely to occur during hospitalisation.

Lack of awareness of community-acquired adverse drug reactions upon hospital admission : dimensions and consequences of a dilemma.

Introduction and objectiveGeriatric patients with multiple comorbidities are at high risk of experiencing an adverse drug reaction (ADR) during hospitalisation. The aim of the study was to compare the rate of ADRs as predicted by a computerised pharmacological database to the actual rate determined by direct observation in a sample of geriatric patients.Study designDuring a 4-month period, geriatric patients were monitored using prospective observation. Patients were intensively screened for ADRs by a pharmacoepidemiological team (PET), consisting of two pharmacists and a physician. Actual ADRs detected by the PET were compared with those predicted by a computerised drug database. Furthermore, the set of actual ADRs, which resulted from drug-drug interactions (DDIs), were contrasted with potential DDIs signalled by the database. The main outcome measures were the incidence of actual ADRs. For the detection rate of the database we focused on frequent ADRs (>1% according to product information and database) and all DDIs indicated automatically by the database.Results163 patients (121 female), mean age 79.8 ± 7.1 years (range 60–98), were included in the study which was conducted on a geriatric rehabilitation hospital ward. The mean duration of hospitalisation was 24.3 ± 8.4 days. Elderly patients received an average of 14.0 drugs (range 2–35) during their hospital stay.Of all patients, 60.7% experienced at least one ADR. The PET detected a total of 153 ADRs, with a mean of 0.9 ADRs per patient (range 0–5). The computerised drug database predicted an average of 309 potential ADRs for each patient; however, only 21 ADRs per patient were of high frequency. In 48% of ADR-positive patients (defined by PET) at least one of these frequent ADRs occurred.DDIs were detected by the PET in 14.7% of patients. Our database indicated a mean of 12 potential DDIs per patient. In 14 out of 24 DDI-positive patients, at least one signal indicated a real DDI. The database sensitivity was consequently 58.3%.ConclusionIn geriatric patients the incidence of ADRs is high. Computerised drug databases are a useful tool for detecting and avoiding ADRs. Our software, however, also produced a large number of signals that did not relate to actual ADRs found by the PET. The sheer number of these ‘false’ signals shows the need for refinement and optimisation of databases for daily clinical use.

Risk Factors Associated with Adverse Drug Reactions Following Hospital Admission : A Prospective Analysis of 907 Patients in Two German University Hospitals

AbstractObjective: Adverse drug reactions (ADRs) are a well-known cause of hospital admission. Nevertheless a quantitative estimate of the preventability of and physicians’ awareness of these reactions is lacking. Study Design and Methods: Using intensive bedside and computer-assisted drug surveillance methods a 13-month prospective pharmacoepidemiological survey was carried out on patients admitted to two medical wards of the Erlangen-Nuremberg University Hospital in Erlangen, Germany. This study aimed to define the incidence of preventable and unavoidable ADRs. In addition we investigated the awareness of the physicians to ADRs at the time of admission and the rate of contraindicated pre-admission prescriptions. Results: In 78 (8.5%) of 915 (10.9%) admissions a total of 102 (42 preventable) community-acquired ADRs were detected on admission. In 45 (3.8%) of the admissions ADRs led directly to hospitalisation. 56.9% of the ADRs were not recognised by the attending physician on admission. Marked correlation was found between the awareness of ADRs and their probability and severity scores (r = 0.85 and r = 0.94, respectively; p < 0.05). The most frequently detected ADRs were due to direct toxicity and secondary pharmacological effects. Idiosyncratic reactions were often missed and 18.6% of all drugs prescribed prior to admission were contraindicated. Leading the list were diuretics, analgesics/NSAIDs and antipsychotics/sedatives. Conclusions: Awareness of existing ADRs on hospital admission and appropriate prescribing prior to hospital admission require attention. Early detection of ADRs on hospital admission can be achieved by the use of computer support systems. Many ADRs could be prevented by adhering to indications and contraindications.

Double-balloon-enteroscopy-based endoscopic retrograde cholangiopancreatography in post-surgical patients.

AbstractBackground: Since the 1970s, studies have examined potential risk factors associated with adverse drug reactions (ADRs) in a variety of settings. However, no pharmacoepidemiological study exists that incorporates clinical and laboratory parameters in a multiple regression model in order to consider predictors for ADRs. Objectives: To characterize risk factors associated with ADRs in patients admitted to university hospital departments of internal medicine. Design and Setting: Intensive pharmacovigilance was carried out in departments of internal medicine of two university hospitals. All admissions were followed prospectively for the occurrence of ADRs by members of a pharmacoepidemiological team consisting of physicians, pharmacologists and pharmacists. To identify patients at high risk for experiencing ADRs, patient histories and several clinical and laboratory data, determined at the time of admission, were taken into consideration. In addition to the drug prescribed, 40 parameters defined vital status at admission. These included temperature, heart rate, blood pressure (systolic-diastolic), body mass index, nicotine and alcohol use, and first laboratory test results after admission on nutrition status, inflammation, liver, kidney, pancreas or thyroid status, electrolytes, blood count and coagulation. Results: 907 patients were observed during the study period. The mean age of the study population was 60 + 16 years. The median number of different drugs administered per patient during hospitalization was 9.6 + 7.7. In 345 patients, 592 ADRs were evaluated: 33.4% possible, 61.5% probable and 4.7% highly probable. Two ADR-related deaths were observed during the study period. Analysing ADR predictors, 17 of 40 parameters reached significance in univariate analysis, but only five in a multivariate binary regression model: raised temperature (odds ratio [OR] 1.609; 95% CI 1.133, 2.285), low erythrocyte levels (OR 0.386; 95% CI 0.194, 0.768), low thrombocyte levels (OR 0.788, 95% CI 0.627, 0.989), high number of drugs (OR 1.117; 95% CI 1.076, 1.159) and female sex (OR 1.562; 95% CI 0.785, 2.013) were independent predictors for ADRs. Conclusion: For the patients investigated, of the large number of clinical data available only five independent factors predict ADR occurrence. Taking these results into account, physicians will be able to focus early on patients at risk for ADRs. To minimize ADR occurrence, ADR predictors should be integrated into the clinical pathway.

Adverse drug events in older patients admitted as an emergency: the role of potentially inappropriate medication in elderly people (PRISCUS).

AIM To evaluate double balloon enteroscopy (DBE) in post-surgical patients to perform endoscopic retrograde cholangiopancreatography (ERCP) and interventions. METHODS In 37 post-surgical patients, a stepwise approach was performed to reach normal papilla or enteral anastomoses of the biliary tract/pancreas. When conventional endoscopy failed, DBE-based ERCP was performed and standard parameters for DBE, ERCP and interventions were recorded. RESULTS Push-enteroscopy (overall, 16 procedures) reached enteral anastomoses only in six out of 37 post-surgical patients (16.2%). DBE achieved a high rate of luminal access to the biliary tract in 23 of the remaining 31 patients (74.1%) and to the pancreatic duct (three patients). Among all DBE-based ERCPs (86 procedures), 21/23 patients (91.3%) were successfully treated. Interventions included ostium incision or papillotomy in 6/23 (26%) and 7/23 patients (30.4%), respectively. Biliary endoprosthesis insertion and regular exchange was achieved in 17/23 (73.9%) and 7/23 patients (30.4%), respectively. Furthermore, bile duct stone extraction as well as ostium and papillary dilation were performed in 5/23 (21.7%) and 3/23 patients (13.0%), respectively. Complications during DBE-based procedures were bleeding (1.1%), perforation (2.3%) and pancreatitis (2.3%), and minor complications occurred in up to 19.1%. CONCLUSION The appropriate use of DBE yields a high rate of luminal access to papilla or enteral anastomoses in more than two-thirds of post-surgical patients, allowing important successful endoscopic therapeutic interventions.