Class IV antidysrhythmics or calcium channel blockers have what action on the cardiovascular system?

Digoxin is a medication that can help the heart pump more blood and slow down the heart rate in certain conditions, such as heart failure and atrial fibrillation.However, digoxin has a narrow therapeutic range, which means that too much or too little of it can be harmful.The therapeutic range of digoxin levels in the blood is 0.5-2 ng/mL, and the toxic level is >2.4 ng/mL.Digoxin should be held if the resting apical pulse of an infant is <90 bpm, an older child is <70 bpm, or an adult is <60 bpm.A pulse of 48/min in an adult is too low and could indicate digoxin toxicity, which can cause life-threatening arrhythmias. Therefore, the nurse should withhold the dose and notify the health care provider immediately.

Choice B is wrong because notifying the health care provider and monitoring the patient’s vital signs are not enough.

The nurse should also withhold the dose to prevent further exposure to digoxin.

Choice C is wrong because rechecking the pulse, making sure to count for 1 full minute, is not necessary.The nurse should already have counted the pulse for 1 full minute before administering digoxin, as per standard procedure.

Choice D is wrong because administering the dose could worsen the patient’s condition and increase the risk of digoxin toxicity and arrhythmias.

Digibind is the trade name forantidigoxin, which is an antibody made up of anti-digoxin immunoglobulin fragments.It is thespecific antidoteto digoxin toxicity, which can occur even when the serum digoxin concentration is within the therapeutic range.Digoxin toxicity causes anorexia, nausea, vomiting, neurological symptoms and arrhythmias.

Choice A, Protamine sulfate, is wrong because it is the antidote for heparin overdose, not digoxin toxicity.

Protamine sulfate reverses the anticoagulant effect of heparin by binding to it and forming a stable complex.

Choice B, Acetylcysteine, is wrong because it is the antidote for acetaminophen overdose, not digoxin toxicity.

Acetylcysteine replenishes glutathione, which is depleted by acetaminophen metabolites that cause hepatotoxicity.

Choice D, Vitamin K, is wrong because it is the antidote for warfarin overdose, not digoxin toxicity.

Vitamin K restores the synthesis of clotting factors that are inhibited by warfarin.

Normal ranges for serum digoxin concentration are 0.6 to 1.2 nanomol/L (0.5 to 0.9 nanograms/mL) for heart failure and unknown for atrial fibrillation without heart failure.

Normal ranges for serum potassium level are 3.5 to 5.0 mmol/L and for serum magnesium level are 0.7 to 1.0 mmol/L.