Det smertestillende middel fentanyl bliver brugt af både unge og misbrugere til at opnå en voldsom rus.In 2019, Bergh et al. examined pharmacodynamic-pharmacokinetic interactions of subcutaneously administered carfentanil in rats. It has been found that carfentanil creates dose-dependent hypothermia and catalepsy, and that is accompanied by nonli