E2: Drugs In Pregnancy

Question 1

What is a teratogen?

Answer 1

• A birth defect or congenital malformation

- abnormal development in an exposed embryo or fetus

Question 2

How does pregnancy affect drug absorption?

Answer 2

-High circulating levels of progesterone slow gastric emptying and gut motility, resulting in slower drug absorption

Question 3

How does pregnancy affect drug metabolism?

Answer 3

-Hepatic drug metabolizing enzymes are induced during pregnancy, may lead to rapid metabolic degradation of drugs, particularly lipid soluble drugs

Question 4

How does pregnancy affect drug excretion?

Answer 4

Renal plasma flow increased by 100% and glomerular filtration rate by 70%, so drugs that are eliminated by the kidneys are eliminated more rapidly than non-pregnant women

Question 5

Drugs that have crossed the placenta enter fetal circulation via what vein?

Answer 5

Th umbilical vein

Question 6

What types of drugs diffuse rapidly across the placenta and enter fetal circulation?

Answer 6

Lipophilic drugs

Question 7

What placental transporter pumps drugs back into maternal circulation?

Answer 7

MDR-1

Question 8

How much folic acid is recommended in pregnancy? Why?

Answer 8

400mcg is recommended for all pregnant women to prevent development of neural tube defects

Question 9

What are the general mechanisms of drugs that should be avoided in pregnancy?

Answer 9

• Damage or inhibit synthesis of DNA or RNA
• Antimetabolites and other cancer treatments
• radiation
• Thalidomide
• isoretinoin
• hormones

Question 10

What is the leading cause of preventable intellectual disability?

Answer 10

Fetal alcohol syndrome

Question 11

Why does fetal alcoholism occur?

Answer 11

-Alcohol diffuses through the placenta, concentration in the fetal blood is the same as in the mothers blood within a few minutes
-The amniotic sack acts as a reservoir for alcohol and prolongs the exposure
-the fetus is only able to metabolize alcohol 10% as fast as the mother because it does not have ALDH.
Build up of acetaldehyde and ethanol decreases transfer of folic acid, amino acids, glucose and other nutrients across the placental barrier

Question 12

What is warfarin syndrome?

Answer 12

-Vitamin K antagonist embryofetopathy is characterized by a group of symptoms that may be observed in a fetus or newborn when the mother has taken oral vitamin K antagonists such as warfarin during pregnancy

** use heparin instead, it does not cross the placenta

Question 13

What are some of the common abnormalities seen with warfarin syndrome?

Answer 13

• Saddle nose
• Depressed nasal bridge
• epiphyseal stippling
• vertebral calcification
• intellectual disability
• short neck
• fetal death

Question 14

What is thalidomide?

Answer 14

• Used as a sedative and to combat nausea in pregnant women

- May damage DNA through oxidative stress and result in multiple limb deformities

Question 15

What is the use and MOA of isoretinoin?

Answer 15

• Used systemically in treatment of severe acne
• retinoids act by activating retinoic acid receptors that bind to specific DNA sequences and effect cellar differentiation and proliferation, or induce apoptosis

Question 16

What can happen if there is exposure to isoretinoin in pregnancy?

Answer 16

• extremely teratogenic

- even a single exposure in the first three weeks of pregnancy can cause birth defects

Question 17

What anticonvulsants are safest in pregnancy?

Answer 17

Gabapentin, Keppra, Clonazepam, lamotrigine

Question 18

What anticonvulsant should be avoided in pregnancy?

Answer 18

Valproate

Question 19

What can happen if Phenytoin or phenobarbitals are taken during pregnancy?

Answer 19

-Fetal hydantoin syndrome (cleft lip, congenital heart disease, slowed growth, and mental deficiency)

Question 20

What could happen if a patient takes carbamazepine or Topiramate during pregnancy?

Answer 20

• Craniofacial anomalies
• developmental delay
• mental retardation

Question 21

What is fetal valproate syndrome?

Answer 21

-Valproic acid in the first trimester of pregnancy is associated with significantly increased risk of major and minor malformations, including neural tube defects, spina bifida, cleft lip, CV abnormalities, GU defects, and autism.

Question 22

What are the effects of ribavirin if there is exposure during pregnancy?

Answer 22

• Malformations of skull, palate, eye, jaw, limbs, skeleton, and GI tract.
• Intrauterine death

Question 23

How are the teratogenic effects of ribavirin avoided in patients of childbearing age?

Answer 23

Both men and women must use 2 forms of effective contraception during treatment and for 6 months after