One of your patients is receiving digitalis orally and is also to receive an antacid at the same time. Your most appropriate action, based on the pharmacokinetics of antacids, is to:
A. Delay the digitalis for 1 to 2 hours until the antacid is absorbed.
B. Give the antacid at least 2 to 4 hours before administering the digitalis.
C. Administer both medications as ordered and documented in the nurse’s notes.
D. Contact the physician regarding the drug interaction and request a change in the time of dosing of the drugs.
Correct Answer: D. Contact the physician regarding the drug interaction and request a change in the time of dosing of the drugs.
When antacids are taken with acidic drugs (for example, digoxin [Digitek], phenytoin [Dilantin], chlorpromazine [Thorazine], [isoniazid]), they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs.
Option A: Avoid taking antacid medicines for indigestion or heartburn within two hours of taking a digoxin dose, because they can stop the digoxin from being absorbed properly if taken too close together.
Option B: Numerous pharmacological agents have been shown to produce clinically significant pharmacokinetic interactions with digoxin. Drugs that reduce digoxin absorption include the antacids aluminum hydroxide, magnesium hydroxide, and magnesium trisilicate, the antidiarrheals kaolin and pectin, the hypocholesterolemic agent cholestyramine and the chemotaxins cyclophosphamide, vincristine, and bleomycin.
Option C: Alteration of the timing of the administration of digoxin from that of a second drug (e.g. as with liquid antacids, kaolin-pectin, or meals of high fiber content), or alteration of the dose of digoxin based on the anticipated change in kinetics (as with spironolactone, quinidine or medications altering gut function or motility), can improve the clinical effectiveness of digoxin therapy.
No comments:
Post a Comment