Exploring drug safety of radiopharmaceuticals

Radioactive substances play an important role in medicine. These so-called radiopharmaceuticals are needed for nuclear scans to diagnose disease and sometimes as a treatment, which uses radiation to kill unwanted cells, such as cancer cells, in the body.In general, radiopharmaceuticals are very safe because the patient is only given tiny amounts. Little is known about adverse events experienced by patients, about interactions with other drugs, and its use in specific patient groups, such as patients with renal insufficiency. In this PhD research we focused on drug safety aspects of radiopharmaceuticals.First, 1002 patients were asked about the adverse events of the radiopharmaceuticals they were injected with before a scan. This was done using a questionnaire specially developed for this purpose. The results showed that patients experience an adverse event with diagnostic radiopharmaceuticals more often than recorded in previous studies. Most of the adverse events reported by the patients, such as a hot feeling, fatigue, or headache, developed shortly after the administration of the radiopharmaceutical but in most cases resolved within a few hours. Our study showed no serious adverse events of diagnostic radiopharmaceuticals according to formal criteria.Furthermore, we investigated the interaction of radioactive glucose in patients with diabetes taking metformin and who were being scanned. It showed that increased colon uptake improved when metformin was stopped for two days before the scan. However, the increased colon uptake, which could influence the assessment of the scan, does partly remain in the last part of the colon. We also investigated the use of radiopharmaceuticals in patients with the rare metabolic disorder porphyria. Most radiopharmaceuticals can probably be used safely in porphyria; some may require preventive measures. For the use of radiopharmaceuticals in patients with impaired renal function we were unable to find sufficient information and therefore further research is needed.With this research we contributed to a better understanding of drug safety of radiopharmaceuticals. This will increase awareness among patients and healthcare providers