Half life Question

[xtreme2001]

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Newbie question!
What time intervals would you dose a 100mg drug with a half-life of 32 hours?
Thanks!

 

[WVUPharm2007]

Depends on the kinetics profile. Is the rate of excretion first-order, zero-order, crazy and variable, does the patient have any renal or hepatic issues, what is the goal plasma level, what is the dose...etc...

 

[xtreme2001]

No other information is provided. The only information provided is a 32hour half-life and 100mg dose.

Would you essentially schedule the drug to be given every 32 hours, to achieve a steady state after 4 doses, and then continue at that rate?

 

[WVUPharm2007]

No other information is provided. The only information provided is a 32hour half-life and 100mg dose.

Would you essentially schedule the drug to be given every 32 hours, to achieve a steady state after 4 doses, and then continue at that rate?

Then it's a poorly written question.

Let's say the effective plasma level for the patient is > 100mg/Vd. Then you might need to take it daily as the single dose wouldn't put you over the needed plasma concentration, however, at steady state, it might be enough.

Take Synthroid for example. It's half-life is several days; yet how is it dosed? Once daily.

 

[KARM12]

No other information is provided. The only information provided is a 32hour half-life and 100mg dose.

Would you essentially schedule the drug to be given every 32 hours, to achieve a steady state after 4 doses, and then continue at that rate?

Go ahead and try to get a patient to take a drug every 32hrs.

This is a bad question because there are so many factors involved...

 

[gsinccom]

Go ahead and try to get a patient to take a drug every 32hrs.

This is a bad question because there are so many factors involved...

yep