Digoxin toxicity can emerge during long-term therapy as well as after an overdose. It can occur even when the serum digoxin concentration is within the therapeutic range. Toxicity causes anorexia, nausea, vomiting and neurological symptoms. It can also trigger fatal arrhythmias. There is a range of indications for using digoxin-specific antibody fragments. The amount ingested and serum digoxin concentration help to determine the dose required, but are not essential. Digoxin-specific antibody fragments are safe and effective in severe toxicity. Monitoring should continue after treatment because of the small risk of rebound toxicity. Restarting therapy should take into account the indication for digoxin and any reasons why the concentration became toxic.