How long does this medicine have a fever?

You did not write what drug it is. If you tagged with the question Orilukast, please read on. Orilukat is not an antipyretic, so no direct temperature-lowering effect can be expected. Fever, on the other hand, is a possible side effect. There is no information on how long such a side effect may last, but after about a day after the last dose, the drug is almost completely eliminated from the body. I enclose additional information about the drug Orilukast, which can be booked through GdziePoLek and collected stationary upon presentation of a prescription: https://www.gdziepolek.pl/produkty/57898/orilukast-tabletki-do-ssania-gryzienia-zucia/apteki/w-warszawie If you think that there is an adverse reaction, it is worth consulting your doctor: https://www.gdziepolek.pl/artykuly/jak-i-dlaczego-zglaszac-dzialania-niepozadane https://www.gdziepolek.pl/telekonsultacja