Stig Ejdrup Andersen, Niels Herluf Paulsen, Per Pfeiffer, Camilla Qvortrup & Per Damkier

Ugeskr Læger 2021;183:V07200556

Some patients may have partial or complete deficiency of dihydropyrimidin dehydrogenase (DPD) and be more likely to experience severe toxicity with 5-fluorouracil. Since the spring of 2020, the Danish Medicines Agency has recommended genotype or phenotype testing before treatment with a fluoropyrimidine, but the most appropriate test strategy is debated. In this review, we present polymorphisms in the genes coding for DPD and summarise the evidence for DPD-enzyme deficiency testing and pharmacokinetic guided dosing.