Guidance for nuclear medicine staff on radiopharmaceuticals drug interaction

Numerous drug interactions related to radiopharmaceuticals take place every day in hospitals many of which are not reported or detected. Information concerning this kind of reaction is not abundant, and nuclear medicine staff are usually overwhelmed by this information. To better understand this type of reaction, and to help nuclear medicine staff deal with it, a review of the literature was conducted. The results show that almost all of radiopharmaceuticals marketed around the world present drug interactions with a large variety of compounds. This suggests that a logical framework to make decisions based on reviews incorporating adverse reactions must be created. The review also showed that researchers undertaking a review of literature, or even a systematic review that incorporates drug interactions, must understand the rationale for the suggested methods and be able to implement them in their review. Additionally, a global effort should be made to report as many cases of drug interaction with radiopharmaceuticals as possible. With this, a complete picture of drug interactions with radiopharmaceuticals can be drawn.Diversos casos de interações medicamentosas com radiofármacos ocorrem diariamente na rotina hospitalar, contudo muitos deles não são notificados ou mesmo percebidos. Informações a respeito desse tipo de reação não é abundante e os profissionais da medicina nuclear muitas vezes estão assoberbados por essas informações. De modo a entender esse tipo de reação e auxiliar a medicina nuclear a lidar com essa situação uma revisão da literatura foi realizada. Os resultados mostraram que a totalidade dos radiofármacos comercializados no mundo apresentam interação medicamentosa com uma enorme variedade de outros medicamentos. Dessa forma sugere-se que revisões sobre radiofármacos inclua um capítulo sobre efeitos adversos. Além disso, um esforço mundial para notificar efeitos adversos deve ser realizado, pois somente dessa forma se terá um quadro real da situação referente interações medicamentosas com radiofármacos

Phosphorylation/dephosphorylation of high-affinity IgE receptors: a mechanism for coupling/uncoupling a large signaling complex.

Engagement of high-affinity IgE receptors leads to activation of tyrosine and serine/threonine kinases and the immediate phosphorylation of receptor beta (serine and tyrosine) and gamma (threonine and tyrosine) chains. Receptor disengagement leads to dephosphorylation of beta and gamma chains via the action of undefined phosphatases. Here we have identified five distinct polypeptides associated with the high-affinity IgE-receptor tetrameric complex, which apparently become phosphorylated and dephosphorylated in sequence with the beta and gamma chains. Like beta chain, polypeptides pp180, pp48, pp42, and pp28 are phosphorylated on serine and tyrosine, whereas pp125 is only phosphorylated on serine. The phosphorylation of each of these receptor-associated polypeptides is antigen-dose dependent and is restricted to activated receptor complexes. Furthermore the physical association between pp125 and the receptor is quantitatively affected by receptor phosphorylation and dephosphorylation, indicating a coupling-uncoupling mechanism. Finally, in vitro kinase experiments show that activated receptor complexes are also physically associated with tyrosine and serine/threonine kinases as part of a larger complex containing the phosphorylated polypeptides