Limitations and obstacles of the spontaneous adverse drugs reactions reporting: Two "challenging" case reports.

INTRODUCTION: Nowadays, based on several epidemiological data, iatrogenic disease is an emerging public health problem, especially in industrialized countries. Adverse drugs reactions (ADRs) are extremely common and, therefore, clinically, socially, and economically worthy of attention. Spontaneous reporting system for suspected ADRs represents the cornerstone of the pharmacovigilance, because it allows rapid detection of potential alarm signals related to drugs use. However, spontaneous reporting system shows several limitations, which are mainly related to under-reporting. In this paper, we describe two particular case reports, which emphasize some reasons of under-reporting and other common criticisms of spontaneous reporting systems. MATERIALS AND METHODS: We performed a computer-aided search of Medline, PubMed, Embase, Cochrane library databases, national and international databases of suspected ADRs reports in order to identify previous published case reports and spontaneous reports about the ADRs reviewed in this paper, and to examine the role of suspected drugs in the pathogenesis of the described adverse reactions. RESULTS: First, we reported a case of tizanidine-induced hemorrhagic cystitis. In the second case report, we presented an episode of asthma exacerbation after taking bimatoprost. Through the review of these two cases, we highlighted some common criticisms of spontaneous reporting systems: under-reporting and false causality attribution. DISCUSSION AND CONCLUSION: Healthcare workers sometimes do not report ADRs because it is challenging to establish with certainty the causal relationship between drug and adverse reaction; however, according to a key principle of pharmacovigilance, it is always better to report even a suspicion to generate an alarm in the interest of protecting public health.

Nexavar(®)-related adverse reactions: Calabrian (Italy) experience for sorafenib exposition in 2012.

Hepatocellular carcinoma (HCC) remains a major global health problem and Calabria in the south of Italy is not an exception. Sorafenib is the first and only Food and Drug Administration approved drug for the treatment of advanced HCC and it is currently under intensive monitoring by the Health Authorities in Italy Agenzia Italiana del Farmaco. This general report has been developed with the aim of briefly reviewing the data found in the reports of adverse reactions (ADRs) collected in Calabria in 2012 for sorafenib treated patients. Extrapolated data have highlighted some differences between the adverse drug reactions reported in patients younger or older than 70 years and other important differences with the current approved leaflet. Several limitations might be present in data analysis form spontaneous reporting, however, the relevance of reporting ADRs (dermatitis, asthenia, vomiting, etc.) for the early identification of drug related signals has to be underlined.

Diagnosis and follow-up of Bartonella henselae infection in the spleen of an immunocompetent patient by real-time quantitative PCR.

Systemic Bartonella henselae infections are unusual in immunocompetent adults. However, here we report one such case of bartonellosis in a 34-year-old patient, who presented with fever and multinodular splenomegaly. We also describe a novel method of identifying Bartonella henselae by real-time quantitative polymerase chain reaction and sequencing of amplified products. This could prevent splenic bartonellosis being mistaken for lymphoma and thereby avert unnecessary splenectomy.

Hepatotoxicity induced by methimazole in a previously healthy patient.

We report a case of hepatotoxicity induced by methimazole treatment in a patient affected by hyperthyroidism. A 54-year-old man, presented to our observation for palpitations, excessive sweating, weakness, heat intolerance and weight loss. On physical examination, his blood pressure was 140/90 mmHg and heart beat was 100/min regular. He had mild tremors and left exophthalmos. Laboratory test revealed a significant increase in serum thyroid hormone levels with a decrease in thyroid stimulating hormone levels. A diagnosis of hyperthyroidism was made and he began treatment with methimazole (30 mg/day). Fourteen days later, he returned for the development of scleral icterus, followed by dark urine, and abdominal pain in the right upper quadrant. Laboratory examinations and liver biopsy performed a diagnosis of cholestatic hepatitis, secondary to methimazole usage. Methimazole was promptly withdrawn and cholestyramine, ursodeoxycholic acid, and chlorpheniramine were given. After five days, abdominal pain resolved and laboratory parameters returned to normal. Naranjo probability scale indicated a probable relationship between hepatotoxicity and methimazole therapy. In conclusion physicians should be aware the risk of hepatotoxicity related with methimazole.