Here’s the scoop on accidentally taking 300 mg a day of hydralazine (Apresoline) instead of the prescribed 30 mg a day.
My mother’s cardiac nurse made a mistake which resulted in the pharmacist preparing her prescription for hydralazine (Apresoline) at 10 times the amount ordered by the cardiologist for high blood pressure.
About a month and a half after my mother began taking hydralazine, my father (who takes charge of all the medications) noticed a mistake:
The bottle said that each pill was 100 mg, but the dosing instructions on the bottle said to take one “10 mg” tablet three times a day.
Was this just a typographical error on the bottle, or were the tablets, that my mother had been taking at this recommendation for about a week, really 100 mg?
Well, when my father went back to the pharmacy to investigate, he compared the newly prepared, 10 mg pills to the ones in the 100 mg bottle, and they were smaller.
Initially she’d been taking just one 10 mg tablet a day. It was then increased to twice a day. Then the instructions came in for three times a day.
My father then noticed the 100 mg on the new bottle, but at first didn’t think much of it—until a week later when he just happened to notice the dosing instruction for “10 mg” three times a day.
So instead of 30 mg a day of Apresoline, my mother had been taking 300 mg a day.
My father said he was on “pins and needles” and refused to dispense to my mother any more of the pills, to clear the perceived overdose out of her system.
He called the cardiologist’s office—this was Friday. The cardiologist was out for the day.
I learned about this on Saturday and did some online research about hydralazine overdose.
I could not find how many mg of this Apresoline drug constituted an overdose, but was relieved to learn that 300 mg a day is actually a common prescription—after it gradually gets raised to this amount.
In fact, one site said 400 mg a day was sometimes prescribed, and one site even had it up to 800 mg.
Furthermore, the half life of hydralazine or Apresoline is three to seven hours, sometimes eight, meaning that half the amount of the drug is already cleared from the system in this time frame.
However, symptoms of an overdose can be the following: faintness, passing out, muscle aches, ankle swelling, chest pain, rapid heart rate.
My mother had none of these. But then again, 300 mg a day is a standard prescription amount.
However, a patient is never jumped from 30 mg a day to 300 mg a day overnight, either.
On Monday morning my parents received the phone call they were waiting for, and the cardiologist’s office told her there was no problem with the 300 mg accidental dosing, and that ironically, the doctor will probably want to go up to 300 mg a day over time anyways.
Hydralazine is a vasodilator—it opens up blood vessels so that more blood could flow through the body.
Lesson learned: Always make sure that you KNOW the dose that the doctor has prescribed, or that the doctor has changed (increased or decreased).
Make sure that this number MATCHES what’s on the prescription bottle.
Read the prescription bottle very carefully, even if you need a magnifying glass.
Have the pharmacist recite to you what the prescription is for. This is your right as the consumer!
