(A) The first signs of digoxin toxicity include abdominal pain, anorexia, nausea, vomiting, and visual disturbances. The physician should be notified if any of these symptoms are experienced. (B) The positive inotropic effects of digoxin increase cardiac output and result in an enhanced activity tolerance. "Feeling better" indicates the drug is working and medication therapy must be continued. (C) Clients should be taught to take their pulse prior to taking the digoxin. If their pulse rate becomes irregular, slows significantly, or is >100 bpm the physician should be notified. (D) Antacids decrease the effectiveness of digoxin.