Continuous infusion, loading dose, & maintenance dosing rate

Question 1

Constant intravenous infusion:

Answer 1

of half-lives to reach steady state plasma concentration of drugs equals the # of half lives for elimination

-rate in=rate out

* take 4 half lives to reach steady state

Question 2

What do we do if we need to achieve therapeutic concentration rapidly?

Answer 2

give loading dose + infusion

Question 3

what is loading dose? equation?

Answer 3

the dose required to quickly reach a specific plasms drug concentration level w/ single administration (IV)

LD (mg)= Vd * desired plasma concentration/bioavailability

Question 4

what is maintenance dose (rate)? equation?

Answer 4

= dose required for regular administration to maintain a target plasma level

MDR (mg/time)= CL * desired plasma concentration/Bioavailability

Question 5

Therapeutic Window

Answer 5

Dosage range between minimum effective concentration and minimum toxic concentration

Question 6

What do you do if there is a narrow therapeutic window?

Answer 6

give more doses over shorter interval minimize peaks and troughs

-if give a larger dose (over a longer period of time) will go above min toxic and below min effect, but sitll be at steady state.