Atropine should be given no more than 30 minutes before or after edrophonium to avoid reducing the effectiveness of each drug. Starting both drugs at the same time may cause both to work too long and wear off too quickly. Atropine is usually given by injection into a muscle once a day. It can be taken by mouth but this form of treatment is less effective. Atropine needs to be given under a doctor's care in a hospital setting because it can cause serious problems if you have an existing heart condition.