<p>Cross-resistance may develop when given with emtricitabine. Exacerbation of anaemia with concomitant use of zidovudine with ribavirin. Increased adverse effects to zidovudine with nephrotoxic or myelosuppressive drugs (e.g. systemic pentamide, dapsone, pyrimethamine, co-trimoxazole, amphotericin, flucytosine, ganciclovir, interferon, vincristine, vinblastine, doxorubicin). Lamivudine and zalcitabine may inhibit the intracellular phosphorylation of one another. Antagonistic effect when zidovudine is used concomitantly with stavudine or doxorubicin.</p>