A 78 year old male was found driving around in his car making abnormal turns and proceeded to drive to a parking lot where he was driving in circles. He presents to the ER with primary symptoms of confusion and cognitive decline. Vital signs were fairly normal with a significantly lower pulse noted.
Upon review of his medication list, it was noted that he was on Digoxin 375 mcg daily. This is a high dose for a middle aged individual. Remember that this patient is 78!
Upon checking a digoxin level, it was quickly confirmed that he had digoxin toxicity. His level was 7.58! Usual upper limit of normal is considered to be about 2. This is the highest digoxin level I’ve ever seen. The part that amazed me was that he really wasn’t displaying many classic digoxin toxicity symptoms. If you ever see an elderly individual on 250 mcg daily or above, this should be an immediate alert in your head to monitor closely for digoxin toxicity. The dosing of 375 mcg daily in this case would be of high concern to (at a minimum) monitor. This gentleman did have some renal insufficiency as well. Always remember that digoxin is cleared by the kidney!
I would also add that with this gentleman’s confusion, it would be nice to try to dig into the patient history to identify if he has had cognitive trouble before digoxin toxicity as well. This is a very high digoxin level and I will never know, but suspect that this patient may have inadvertently been taking more than one tablet per day. What’s the highest digoxin level you’ve seen?
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