Pharmacology Preg+Lactation Flashcards
Polymorphisms of CYP450 Isoenzyme is an altered ________ results in _______
CYP2D6, ultra rapid metabolization
Codeine is broken down into
Greater quantities of morphine than normal
Genetic variability that affects morphine is
Genetic variability in UGT2B7 may increase formation of morphine-6-glucuronide–> Resp. depression mom and baby
For the mother, what changes occur to B2 receptor?
Changes at B2 adrenergic receptor , alter tocolysis, require less ephedrine
Physiological changes during pregnancy including changes in ____, _____, _______ affect AUDME
CV, resp, hemodynamics
CO and Absorption: what changes occur?
Give an example
Increase in CO to skin and mucous membranes enhances absorption. Example is that if you give a fentanyl patch, increase absorption, may lead to more absorption
What happens to uptake on IA during pregnancy ?
Increase MV and Decrease FRC Increase pulmonary uptake
An increase in CO during pregnancy leads to
Distribution of drug to all tissues.
What happens when there is a delay in increase in arterial and brain ?
A delay in increase arterial and brain anesthetic concentration will result in increased in peripheral perfusion .
When there is an increase peripheral perfusion?
There in an increase of return of drug during elimination phase.
Hydrophyillic drugs such as _______-have a ___vd
NMB; small
What happens to plasma albumin concentration ?
Decreased by 30%
As far as protein concentration, it only affect
Highly protein bound drugs
Explain CO and partial pressure and how one affect the other
IF you don’t have the partial concentration in the CNS , it doesn’t matter how high your CO is, you can’t go to sleep.
What happens to TBW with pregnancy? Significance?
Increase on average by 8L ; Affect distribution
What happens to intravascular plasma?
Increase by 40%
The ECF gain in pregnancy depends on
Weight gain and edema
Not clear if this is increased despite increase in CO
Hepatic blood flow
Recommended Caffeine amount and why?
Because of Decrease enzyme activity
CYP450 IsoEnzymes activities that are increased are
CYP 34A, CYP2D6, CYP2C9
UGT
UGT enzymes that are induced are
UGT1A4 and UGT2B7
The enzyme affecting phenytoin and how?
Enzyme CYP2C9 induces phenytoin and increase it metabolism
The enzyme affecting midazolam and how?
Enzyme CYP3A4 induces midazolam and increase it metabolism
The enzyme affecting morphine and how?
Enzyme UGT2B7 induces morphine and increase it metabolism
CYP450 IsoEnzymes activities that are Decreased are
CYP1A2 and CYP2C19
Enzyme responsible for Codeine and Morphine ________ and it it increased or decreased?
CYP2D6; Increased
Which enzyme activity reduces caffeine and theophyiline metabolism?
CYP1A2
What happens to RBF not when in labor in general?
Increase by 60-80%
Increase ________excretion of unchanged drugs
Renal
Most commonly administered medication and renal excretion implication?
Cephalosporin (Ancef most common); Because of increased renal excretion , may need more FREQUENT dosing
Activity of transport proteins is__________
Increased
Transporter proteins is_______and may contribute to what about digoxin?
Renal P-Glycoprotein; increase clearance of digoxin in pregnancy , may have to get level and increase dose
What about drugs that are metabolized by the liver?
They may require increase or decrease in dose depending on the METABOLIC PATHWAY
If a drugs is excreted unchanged by the kidney it often require what kind of dosage adjustments
Increase dose
Placental transfer in mainly via ____and favors movement of ________ drugs
Diffusion; Lipophillic
Fetal pH vs Maternal pH meaning?
Fetal pH lower than maternal pH ; weak bases become more ionized in the fetus. Limit transfer back across the placenta.
Ion trapping is irrelevant but fetal acidosis can
Significantly increase the fetal concentration of drugs such as local anesthetics. Trapped LA can lead to TOXIC buildup
Placenta have that type of enzymes
UGT enzyme that can catalyze phase II conjugation
Placenta acts as a mini ________ and you may need to ______dose
liver; increase
Why you may need to increase dosing due to placenta “mini” liver work ?
UGT enzymes in placenta doing work
UGT in liver doing work
Fetal circulation makes drug undergo
1st pass hepatic metabolism
Elimination of drugs by fetus mainly reliant on
Placental transfer
Fetus has minimal renal BF due to _____ until term pass into
Increase renal vascular resistance; Amniotic fluid to be swallowed.
Which hormone enhances sedation?
Progesterone
Endorphins during pregnancy
Enhanced anti-nociception ; less fentanyl or opioids or anesthetic requirements.
Inhalational Anesthesia changes : MAC____due to
MAC reduced by 30% during gestation ; progesterone
When does MAC return to normal
12-72 hours after delivery
Opioids on MAC
Decreases MAC so endorphins may also factor in.
What is MAC really measuring?
movement
CO and IV anesthetic dose
Changes in Pregnancy?
Increase CO = Increase in IV anesthetic dose to produce central effects.
8-18% decrease in dose requirements for IV anestheticvs
Local anesthesia changes
Increases spread of Neuraxial block
Epidural Blood volume is ________ = ________ capacity of epidrual space and ________volume of lumbar CSF
Increased; decreased; decreased
What happens to LA?
Increased Sensitivity to LA probably progesterone.
Decrease the dose of LA
CSF little bit + small volume
Increase effect
CSF little bit + Large volume
Decrease effect
Changes in anesthesia in threshold can be reproduced using
Exogeneous progesterone and Estrogen
Parts of brain appear to be involve are
Spinal cord Kappa and delta opioid receptors
Descending spinal alpha-2 noradrenergic pathways
How long does the analgesia changes last?
24-48 hours after delivery
2 alpha -2 agonist involves in pain reduction
Clonidine
Precedex.
Drugs that can cause harm to fetus during pregnancy are called
Teratogen
Teratogens are
substances that act to irreversibly alter growth, structure or function of the developing embryo,
Major malformations 3 types
- Incompatible w/ survival such as ancephaly
- Requires major surgical correction (cleft palage, CHD)
- Causes mental retardation
Minor malformations are the one that
Do not alter quality of life such as ear tags , extra digits
When possible , use
non-pharmacological techniques whenever possible
What are some exogenous causes of birth defects? (REDIM)
Radiation, infections, maternal metabolic disorders, Drugs, environmental chemicals
All or nothing exposure
Exposure in 1st 2 weeks of conception are all of nothing (no effect or spontaneous fetal loss)
What is the classic period of susceptibility during period of organogenesis?
2 1/2 to 8 weeks after conception
Giving Thalidomine
at _________ leads to _______
at _______leads to ______
35-37 days ; ear malformations
41 -44 days: AMELIA or PHOCOMELIA
After organogenesis, up to ____weeks, embryonic deveoopment mainly consist of _______
8; increase organ size.
What is the best time to do surgery if needed ?
2nd Trimester
Doing surgery during 1st trimester may lead to ______While doing in on 3rd trimester may lead to _______.
Spontaneous abortion
Go into labor
CNS development goes up to
16 weeks
Heart development goes up to
6 1/2 weeks
Upper limb development goes up to
7 weeks
When is the classic Teratogenic period
31 days to 71 days
After 8 weeks only
GROWTH is affected mainly
FDA pregnancy Category A
Controlled studies of pregnant women show no risk in 1st trimester
FDA pregnancy Category B
Animal studies show no risk, or animals show risk UNCONFIRMED In humans
FDA pregnancy Category C
Animal studies show risk, caution is advised, benefits may outweigh risks
FDA pregnancy Category D
Evidence of risk to human fetus, benefits may outweigh risks in serious conditions
FDA pregnancy Category X
Risks outweighs benefit
Remember all category drugs
in a speficic category do not all have the same risks
Aspiring has been associated with
Gastrochisis
Use of 1st trimester Aspirin can cause
increased risk of pregnancy loss
Use of 2nd trimester Aspirin can cause
Undescended TESTICULAR syndrome