Can Treatment For TB Lead To Nausea, Vomiting And Drowsiness?

hi doctor my husband was diagnised positive in feb 2010 his CD4count was72 Hb-5 immediate treatment of duovirN was given iron tablets prescribed, after 6 months of complete bed rest he recovered in october but unfortunately hiscounts again droppedto 203 from280cd4 doctor has started treatment for t.b other infections duovir and effavir AGAIN HIS NAUSEA drowsiness vomiting sensation has increased. he feels very weak and is almost asleep all the time. he is a Ca by profession and the sole bread earner please suggest