Hos patienter, der tidligere har fået medicin mod deres hiv- infektion, uden at denne medicin har virket, bør lægen, inden Emtriva ordineres, gennemgå patientens tidligere antivirale medicin og vurdere chancen for, at infektionen med det pågældende virus kan behandles med nogle af de andre nye antivirale lægemidler, der eventuelt kan ordineres.
For patients who have taken medicines to treat their HIV infection before and failed to respond to that treatment, doctors should only prescribe Emtriva once they have looked at the antiviral medicines the patient has taken before and assessed the likelihood of the virus ’ s response to any new antiviral medicines that might be prescribed.