Digoxin

[jeffradd]

how many days should i consider 125mcg PO QD to reach its steady state?

[Jeff]

Originally Posted by jeffradd

how many days should i consider 125mcg PO QD to reach its steady state?

Biological half-life - Wikipedia, the free encyclopedia
"So, for example, digoxin has a half-life (or t½) of 24-36 hours; this means that a change in the dose will take the best part of a week to take full effect"

However I can't see a reason for taking digoxin 125mcg QD rather than 500mcg as a daily dose - but that's just intuition - I haven't gone through the maths.

Is the intention to reach a steady state or to establish a clinical effective more quickly and then reduce the dose?

Jeff

[jeffradd]

Jeff thanks. to reach steady state. how many days?

[johnep]

Sounds like high dose to me. Too many deaths in past to make me complacent.
Latest was 250mcg instead of 62.5mcg in a MDS tray.
johnep

[jeffradd]

im not a professional. its just a question.

[jeffradd]

so about one week to reach steady state???

[Jeff]

Yep - a longer quote from the wiki link I gave in my first reply.

"In clinical practice, this means that it takes just over 4.7 times the half-life for a drug's serum concentration to reach steady state after regular dosing is started, stopped, or the dose changed. So, for example, digoxin has a half-life (or t½) of 24-36 hours; this means that a change in the dose will take the best part of a week to take full effect."

So 4.7 x 1 (day if 24 hour half life) = 4.7 days
or 4.7 x 1.5 days (if a 36 hour half life) = 7 days

Jeff

[jeffradd]

thanks for your help and a great explanation

[Pharmanaut]

Originally Posted by Jeff

Biological half-life - Wikipedia, the free encyclopedia
"So, for example, digoxin has a half-life (or t½) of 24-36 hours; this means that a change in the dose will take the best part of a week to take full effect"

However I can't see a reason for taking digoxin 125mcg QD rather than 500mcg as a daily dose - but that's just intuition - I haven't gone through the maths.

Is the intention to reach a steady state or to establish a clinical effective more quickly and then reduce the dose?

Jeff

Is QD the same as OD as written here in UK?

[Pharmanaut]

QD seems to be once a day in the US.
Glad we use OD instead in the UK it could be taken for QDS.

http://www.ismp.org/Tools/errorproneabbreviations.pdf