In vitro studies indicate that the activation of stavudine is inhibited by doxorubicin and ribavirin but not by other medicinal products used in HIV infection which are similarly phosphorylated, (e. g. didanosine, zalcitabine, ganciclovir and foscarnet) therefore, coadministration of stavudine with either doxorubicin or ribavirin should be undertaken with caution.