Role of microRNAs in fluoropyrimidine-related toxicity: what we know.

Although more than half a century has passed since the discovery of fluoropyrimidines, they are still used in the treatment of many types of cancer, and it is estimated that annually two million patients undergo fluoropyrimidine-based chemotherapy. The toxicity resulting from the use of fluoropyrimidines affects about 30-40% of patients, which in some cases may prove to be lethal. The key player in fluoropyrimidine toxicity is DPD activity, and patients with deficits are more likely to develop significant adverse events. In addition to genotyping DPYD variants associated with DPD deficiency, overexpression of miR-27 has also been shown to be a predictive factor for fluoropyrimidine toxicity. This review aims to relate what we know so far about the involvement of miRNA in fluoropyrimidine toxicity and to open new perspectives in this field.

How often we diagnose allergy to ranitidine?

H2 receptors' antagonists (H2RA) are widely used drugs and they are generally well-tolerated. Ranitidine hypersensitivity reactions (HR) are rarely reported. The article emphasizes the importance of recognizing ranitidine as a cause of anaphylaxis and the advantages and limits of allergological evaluation to establish a positive diagnose. We reviewed a series of published cases of ranitidine-induced hypersensitivity reactions, starting from a clinical case presentation. Moreover, we analyzed the ranitidine related adverse events in the Eudravigilance European database of adverse reactions. Most of the allergic reactions induced by ranitidine are type I HR with immediate onset after exposure, with variable clinical presentation. But in a few cases, there were also described delayed reactions, some after occupational exposure. The article underlines the importance of allergy evaluation to avoid future contact with the drug to reduce the risk of more severe reactions. The suspected reactions should be reported, allowing pharmacovigilance systems to analyse them and to establish further recommendations for clinicians.