Chapter 8- Pregnancy And Breastfeeding Flashcards
When is the second trimester?
13-28 weeks
When is the 3rd trimester?
After 28 weeks
In pregnancy, how does progesterone affect gastric emptying?
Slows gastric emptying resulting in slower absorption and lower peak drug concentrations
How is drug distribution altered in pregnancy?
Total body water increases which should dilute drug BUT serum albumin falls and pregnancy steroids displace drugs from their binding proteins so increase ‘free’ drug
How does being pregnant affect drug metabolism?
Pregnancy can affect enzymes e.g the enzyme which inactivates lamotrigene is induced by pregnancy so higher doses needed
How is drug excretion affected in pregnancy?
In pregnancy you have a higher cardiac output leading to an increase of 50% GFR thus renally excreted drugs e.g penicillin are excreted faster (higher doses needed)
What is physiological glycosuria and what’s it caused by?
Glucose in the urine caused by increased cardiac output this increase GFR
Why are beta blockers less likely to cause bradycardia in pregnancy?
Cause pregnancy often comes with tachycardia
Why are calcium channel blockers less likely to decrease total peripheral resistance in pregnancy?
Cos total peripheral resistance is already reduced in pregnancy
If a patient is taking a teratogenic agent in the first 8 weeks of pregnancy (during embryogenesis) what will result?
Anatomical malformation
If a patient is taking a teratogenic agent later in pregnancy what will result?
Function of the baby will be affected
How do drugs cross the placenta?
Simple diffusion
Can heparin cross the placenta?
No MW 15000
When is teratogenicity most susceptible?
Between 3-11 weeks of pregnancy during organogenesis
Why does glucose tolerance decrease in pregnancy?
Because of the anti insulin effects of human placental lactogen, glucagon and cortisol
What minor malformations are associated with use of anticonvulsants in pregnancy?
Low set ears
Broad nasal bridge
Irregular teeth
Hypo plastic nails and digits
