Drugs in Pregnancy
Effects of Pregnancy on Drugs
Drug clearance increases during pregnancy as a result of increased cardiac output (hence renal elimination) and rate of metabolism. Doses of drugs often need to be higher in the 2nd and 3rd trimesters.
Clearance reverts quickly after delivery.
Trimester 1
Trimester 2
Trimester 3
Postpartum
13
26
40
normal adult
1.5 x adult
Cl/m