Mrs. Foxglove is an 89-year-old lady, living independently in a Seniors’ Residence. On a hot summer day she comes to the ED feeling “weak and dizzy” with “no energy”. She says she doesn’t feel sick, and she has no fever, no chest pain, and no dyspnea – just no appetite and “no energy”!
- PMH: atrial fibrillation, CHF
- O/E: HR 42 BP165/80 RR 20 Normal mental status
- Labs: increased BUN, Cr, and digoxin level
We can see her symptoms of “weak and dizzy” are clearly caused by the bradycardia in turn caused by the the digoxin toxicity.
- But why did she get so dig toxic?
Take Home Point
The dose of a medication you give MAY NOT produce the serum concentration that you wanted or expected in the older patient.
Since renal function naturally decreases with age, drug accumulation is likely and drug effects can be prolonged.