Question

A patient is 26 weeks pregnant with her first child. She was recently hospitalized for a severe manic episode during which she put her and baby's life in danger. After careful consideration with many health care professionals, she has made the decision to restart her lithium. Prior to pregnancy, this patient had been successfully maintained on a lithium dose of 300 mg, PO, three times daily. The nurse would counsel this patient that the risk for effects on the fetal heart is ____________ in this trimester than it is in the first trimester, and that she is likely to need an ____________ dose of the medication at this point in her pregnancy. (consider risk of birth defects, and consider pharmacokinetic changes during pregnancy). Question 9 options:

a) higher; increased

b) lower; decreased

c) lower; increased

d) the same; increased

Answer 1

Lithium is the effective drug of choice for treating bipolar disorder in pregnancy,but it also put some risk in pregnancy.

From the above case, the correct answer is option C. That is risk of cardiac malformation to fetus is decrease as compared to first trimester ,because most of the growth and development is occurring at the first trimester. The most common cardiac malformation is ebstein's Anomaly.

Generally the lithium dose increase during pregnancy ,because the main excretion of lithium is take place at the kidney so GFR (glomerular filtration rate) and intravascular fluid volume is affect the lithium dosage. In pregnancy GFR are increased so the dose of lithium also increased. But in the late pregnancy GFR if decreases and fluid volume increase so close monitoring of plasma lithium level is mandatory. Should monitoring plasma lithium level 4 times in 3 week and in later pregnancy monitor it in weekely.