What are the Characteristics of Patients Experiencing Adverse Drug Reactions to Oral Anticogulants and How Can Such Reactions be Prevented?

INTRODUCTION: Oral anticoagulants, including vitamin K inhibitors (VKAs) and direct anticoagulants (DOACs) are important for preventing and treating thromboembolic diseases. However, they are not recommended for use in all patients due to negative side effects and adverse drug reactions (ADRs). Currently, there is a paucity of information about their use in real life. Therefore, the aim of this pilot study is to report on the rate of serious ADRs in oral anticoagulant users, determine patient characteristics associated with increased risk of ADRs, and identify possible management strategies for reducing risk of ADRs within a hospital setting. METHODS: Patients admitted to the Internal Medicine Department of the Vimercate Hospital were recruited between November 1, 2015 and October 31, 2016. All patients reporting an ADR associated with anticoagulant use were selected. Demographic, clinical, and observational data were extracted from electronic hospital records, in particular, by the hospital discharge letters and other clinical records. The main outcome of the study was to evaluate the incidence of anticoagulants serious adverse drug reactions conditioning hospital admission, the percentage of preventable reactions, and the determinants of those. RESULTS AND DISCUSSION: Of the 2,064 admissions, 102 (4.9%) eligible patients were identified. Age ranged from 60-95 years (mean = 81.9, standard deviation = 6,59) and 47.1% (n=48) were female. Of the 102 cases, 68 used VKAs and 34 used DOACs. The most common admission diagnosis was heart failure following anemia or hemorrhage (56 cases), followed by acute hemorrhage (with or without anemia; 29 cases), and anemia not associated with evident hemorrhage (17cases). The majority of VKA users (n=65, 95.6%) had a high risk of major bleeding. ADRs were found to be preventable in 96% of VKA users and 68% of DOACs users. CONCLUSION: This study highlights the large percentage of ADRs from oral anticoagulants that can be avoided with more careful patient management. Periodic check-up of cardiac and renal function, as well as blood count, may be useful for reducing the risk of ADRs, especially in older DOACs users. Further research is needed to get new data to improve the patients monitoring system.

Comparative safety profiles of intravitreal bevacizumab, ranibizumab and pegaptanib: the analysis of the WHO database of adverse drug reactions.

PURPOSE: The purpose of this study is to conduct a comparative analysis of the suspected adverse drug reactions (ADRs) associated with intravitreal bevacizumab, ranibizumab and pegaptanib in the WHO database in order to have a real-life information on these drugs, which now is only based on data coming from clinical trials. METHODS: ADR reports for intravitreal use of bevacizumab, ranibizumab and pegaptanib from January 2002 to December 2012 were selected from the WHO-VigiBase. Reporting odds ratio (ROR) with confidence interval of 95 % and p value was calculated. The analysis was performed for drug-reaction pairs. The Medical Dictionary for Regulatory Activities (MedDRA) terminology for ADRs was used. RESULTS: The analysis was performed on 3180 reports corresponding to 7753 drug-reaction pairs. Significant RORs for endophthalmitis and uveitis (1.90, 95 % confidence interval (CI) 1.48-2.43, and 10.62, 6.62-17.05, respectively) were retrieved for bevacizumab, and cerebrovascular accident and myocardial infarction produced significant ROR (1.54, 1.14-2.10 and 1.73, 1.18-2.53, respectively) for ranibizumab. Pegaptanib was significantly associated with visual impairment (1.98, 1.12-3.5, p = 0.02), nausea (3.29, 1.57-6.86, p < 0.001), vomiting (2.91, 1.2-7.07, p = 0.01) and drug hypersensitivity (8.75, 3.1-24.66, p < 0.001). CONCLUSIONS: Our data showed an elevated disproportionality for cardiovascular ADRs in patients treated with ranibizumab and for infective ocular reactions in those treated with bevacizumab. No relevant safety issues were identified for pegaptanib. These findings suggest bevacizumab as a suitable choice for AMD therapy due to its effectiveness similar to that of ranibizumab, its favourable safety profile and for its lower cost.

Spontaneous reporting of drug-related hepatic reactions from two Italian regions (Lombardy and Veneto).

BACKGROUND AND AIMS: Many currently used drugs are implicated in liver disorders ranging from asymptomatic abnormal liver function tests to fatal liver failure, and drug-induced hepatic reactions are the most frequent cause of the withdrawal of drugs from the market in the United States, United Kingdom and Spain. The aim of this study was to review the drug-induced hepatic reactions notified to the spontaneous surveillance system of two Italian regions (Lombardy and the Veneto) up to 31 December 1998. PATIENTS AND METHODS: The reports of hepatic adverse drug reactions were extracted from an inter-regional database of spontaneous adverse drug reaction reports and analysed by reporter category, patient age and sex, the underlying disease, the adverse reaction and drug exposure. In the case of drugs involved in more than four reports, a search was made of the Medline, Hepatox, Micromedex and WHO databases. RESULTS: Between 1988 and 1998, there were 310 reports of hepatic lesions associated with single drugs or fixed combinations, the most frequently involved patient categories being females and the elderly. Sixty percent of the reactions were classified as serious, with three fatal cases. Thirteen drugs were associated with more than four reports and accounted for 35% of all of the hepatic reactions. Six drugs not known as hepatotoxic agents were associated with hepatic reactions. CONCLUSIONS: In this study, spontaneous reports have suggested previously unknown hepatotoxicty of six drugs, and have improved drug safety profiles as shown in an Italian inter-regional health service.

Cutaneous reactions to drugs. An analysis of spontaneous reports in four Italian regions.

AIMS: Cutaneous manifestations are frequently reported in association with drug use. The aim of this study was to analyse the skin reactions reported to the spontaneous surveillance systems of four Italian regions (Friuli Venezia Giulia, Lombardy, Sicily and the Veneto), and correlate the reports with estimated drug consumption during the same period, paying particular attention to the reactions to antimicrobial agents and nonsteroidal anti-inflammatory drugs (NSAIDs). METHODS: All of the adverse drug reactions (ADRs) reported spontaneously between January 1996 and December 1997 to the surveillance systems of four Italian regions (a total population of about 20 million people) were analysed by a panel of experts including dermatologists. On the basis of the Critical Term List of the World Health Organization (WHO), the reactions were classified as either serious or nonserious events. Drug consumption was expressed as a daily defined dose (DDD)/1000 inhabitants/day. RESULTS: A total of 2224 adverse skin reaction reports (44.7% of all of the reported ADRs) were identified, making a reporting rate of about 5.5 per 100 000 inhabitants/year. The female/male ratio was 1.58, and the reporting rate progressively increased with age. The drug categories with the highest number of cutaneous reactions were antimicrobials, followed by NSAIDs, analgesics and radiology contrast media. There was a total of 372 (16.9%) serious reaction reports, the most frequent being angioedema (171 cases), erythema multiforme (68 cases) and photosensitivity (37 cases). Co-trimoxazole, followed by the cephalosporins and fluoroquinolones, were associated with the highest consumption-related reporting rate among the antimicrobials, and aspirin and dipyrone among the NSAIDs and analgesics. CONCLUSIONS: Spontaneous reports from four Italian regions revealed that the skin was the organ most frequently affected by ADRs. The paper shows the validity of a regional decentralized system in Italy.

Thyroid storm with encephalopathic symptoms due to Graves' disease and inappropriate secretion of thyrotropin.

A 41-year-old woman is described, first hospitalized in the neurosurgical department for a transient ischemic attack with left hemiparesis followed after 6 hours by tonic-clonic seizures starting from the left hemiface and quickly generalized. Brain computed tomography (CT) scan and magnetic resonance imaging were normal. Clinically the patient presented tremor, tachycardia, generalized muscle weakness, and profuse diaphoresis. T4 and T3 were elevated. The patient was transferred from the neurosurgical to the medical department where a thyroid storm due to autoimmune Graves' disease with normal thyrotropin (TSH) values responsive to thyrotropin-releasing hormone (TRH) stimulation was diagnosed. A syndrome of inappropriate secretion of TSH was suspected in an unusual presentation as autoimmune Graves' hyperthyroidism. The TSH alpha-subunit and alpha-subunit/TSH molar ratio were normal, which supported the diagnosis of non-neoplastic inappropriate secretion of TSH. However, severe autoimmune Graves' hyperthyroidism is very rare indeed because autoantibodies to thyroid antigens are generally non-detectable in such patients. Our patient was treated initially with barbiturates, then with dexamethasone, Lugol's solution, methimazole and propranolol. Treatment of this patient proved difficult, and definitive improvement was obtained only after triiodothyroacetic acid administration, but methimazole and propranolol administration could not be discontinued. Fine needle aspiration biopsies of the thyroid in 2 occasions showed follicular or follicular-papillary proliferation with lymphocytic infiltration as in chronic thyroiditis. The patient is now in good clinical conditions and is followed up regularly. Autoimmune Graves' hyperthyroidism may be associated in extremely rare instances with non neoplastic inappropriate secretion of TSH.