The disclosed subject matter provides a dosing regimen and administration schedule for the use of 1-deoxygalactonojirimycin ((2R,3S,4R,5S)-2-(hydroxymethyl) piperdine-3,4,5-triol) or its salt migalastat hydrochloride and agalactosidase A (a-Gal A) enzyme replacement therapy for the treatment of Fabry disease. The a-Gal A enzyme replacement therapy includes replacement enzymes agalsidase alpha (Replagal) and agalsidase beta (Fabrazyme). Disclosed is a dose of 50-600 mg of 1-deoxygalactonojirimycin or migalastat hydrochloride, administered to patients fasted for up to four hours before enzyme replacement therapy and/or administered up to four hours prior to enzyme replacement therapy where subsequent therapy is administered every two to four weeks.
