A mother calls the nurse to report that at 0900 she administered an oral dose of digoxin to her 4-month-old infant, but at 0920 the baby vomited the medicine. Which instruction should the nurse provide to this mother?

Choice A: Administering a half dose now is not advisable, because it may result in underdosing or overdosing of digoxin. Digoxin has a narrow therapeutic range and a high risk of toxicity, especially in infants and children. The amount of digoxin absorbed by the infant before vomiting is unknown, so giving a partial dose may not achieve therapeutic levels or may exceed safe levels.

Choice B: Giving another dose is not advisable, because it may result in overdosing of digoxin. Digoxin has a narrow therapeutic range and a high risk of toxicity, especially in infants and children. The amount of digoxin absorbed by the infant before vomiting is unknown, so giving a full dose may exceed safe levels and cause adverse effects such as nausea, vomiting, bradycardia, arrhythmias, or visual disturbances.

Choice C: Mixing the next dose with food is not advisable, because it may affect the absorption and bioavailability of digoxin. Digoxin should be taken on an empty stomach or at least one hour before or two hours after meals, because food can interfere with its absorption from the gastrointestinal tract and reduce its effectiveness.

Choice D: Withholding the dose is the safest option. If vomiting occurs within 30 minutes of administration, it’s generally advised to skip that dose to avoid the risk of overdose. The next dose should be given as scheduled Digoxin has a long half-life and accumulates in tissues, so missing one dose will not significantly affect its therapeutic effect. Withholding this dose will avoid overdosing and toxicity of digoxin, which can be life-threatening in infants and children. The nurse should also advise the mother to resume the regular dosing schedule and monitor the infant's pulse rate and signs of digoxin toxicity.