Pharmacology

Question 1

how might pregnancy physiologically change absorption of drugs?

Answer 1

Oral: decreased GI motility and increased GI blood flow due to progesterone

IM/SC/Inhaled/transdermal: increased blood flow to muscles, lungs, subcutaneous tissues

Question 2

how might pregnancy change the PK effect of drugs?

Answer 2

oral: changes in rate and exten of absorption

IM/SC/ Inhaled/transdermal: potentially increases absorption

Question 3

how might pregnancy physiologically change distribution of drugs?

Answer 3

increased plasma volume and cardiac output; redistribution of blood flow

plasma proteins: decreased albumin; increased acute phase proteins

Question 4

how might pregnancy change the PK effect of drugs?

Answer 4

increased Vd possible with decreased plasma concentrations

increased free fraction of acidic drugs with increased distribution

Question 5

how might pregnancy physiologially change the metabolism of drugs?

Answer 5

• increased hepatic blood flow
• decreased protein binding
• increase/decrease metabolizing enzymes

Question 6

how might pregnancy change the PK effect of metabolism?

Answer 6

• increased delivery of high ER drigs to liver to metabolism
• increased delivery of free drug to liver for low ER drugs
• drug dependent increases or decreases in metabolism

Question 7

how might pregnancy physiologically change elimination of drugs

Answer 7

increased renal blood flow and GFR, increased CO

Question 8

how might pregnancy effect the PK of elimination of drugs?

Answer 8

increased renal elimination of hydrophilic drugs

Question 9

molecular weight effect on drug transfer

Answer 9

smaller drugs have increased permeability

Question 10

pKa effect on drug transfer with pregnancy

Answer 10

drugs can only cross the placenta in the unionized form; fetal pH is lower compared to maternal pH, therefore some drugs may undergo ion trapping and persist/accumulate in the fetus

Question 11

protein binding effect on drug transfer with pregnancy

Answer 11

drugs can only cross the placenta if they are in the unbound form; drugs with lower protein binding will have increased permeability

Question 12

concentration effect on drug transfer with pregnancy

Answer 12

higher concentrations in the maternal blood will result in a larger concentration gradient and greater diffusion of drug across the placenta

Question 13

teratogenic drugs administered to dogs at therapeutic doses

Answer 13

griseofulvin
testosterone/estrogens
tetracyclines
trilostane/mitotane

Question 14

teratogenic drugs administered to cats at therapeutic doses

Answer 14

griseofulvin
testosterone/estrogen
tetracyclines

Question 15

teratogenic drugs administered to horses at therapeutic doses

Answer 15

griseofulvin
TMS, pyrimethamine, folic acid

Question 16

teratogenic drugs administered to sheep at therapeutic doses

Answer 16

Oxfendazole, albendazole, febantel

Question 17

antibiotics safe for use in pregnancy

Answer 17

beta lactams
macrolides
lincosamides

Question 18

endocrine drugs safe for use in pregnancy

Answer 18

insulin and levothyroxine

Question 19

heartworm preventatives safe for use in pregnancy

Answer 19

heartguard and revolution

Question 20

flea and tick meds safe for pregnancy

Answer 20

frontline and maybe bravecto

Question 21

t/f: it is possible to give a dose that is harmless to the mother and fatal to the fetus

Answer 21

T

Question 22

when are fetuses the most susceptible to teratogenesis

Answer 22

the first trimester
- dogs day 14-30
- cats day 14-26
- horses less than day 60

Question 23

how do drugs cause teratogenesis?

Answer 23

1. alter gene expression of the fetus
2. alter apoptosis, cell migration, cell proliferation
3. alter synthesis and function of proteins and nucleic acids
4. alter supply of energy sources

Question 24

teratogen

Answer 24

an agent or factor that causes inflammation of an embryo

Question 25

the placenta is an __ barrier

Answer 25

incomplete

Question 26

what would cause increased placental drug transfer?

Answer 26

smaller molecular weight
higher lipid solubility
unionized
lower protein binding
higher concentration gradient