De kendte bivirkninger, som hovedpine, rødmen, smerter i ekstremiteterne og ødemer, ses hyppigere hos sildenafil/ epoprostenol- behandlede patienter sammenlignet med placebo/ epoprostenol- behandlede patienter.
The known adverse events headache, flushing, pain in extremity and oedema were noted in a higher frequency in sildenafil/ epoprostenol treated patients compared to placebo/ epoprostenol treated patients.