My friend is taking erythromycin and has had a horrible reaction to it. I have checked on here and it looks like lots of people either get very bad sickness or stomach pain with it. She has stopped taking it and is due to see the doctor tonight. The last tablet she took was Tuesday morning but she still feels very sick. I was just wondering how long you think it might be until the sickness and nausea she's feeling starts to lift. She only took one evening, a full day and one morning dose. Thanks very much.