MODULE 1
What are the BON rules and regulations for prescriptive authority for
the advance practice nurse?
Texas is very restricted
Describe the pharmacokinetic processes of absorption, distribution,
metabolism and elimination and how differences in these areas affect
drug action.
Absorption
Drug’s movement from the site of administration into the
blood.
Distribution
Drug’s movement from the blood into the interstitial space
of tissues and from there into cells.
Metabolism
Biotransformation is the enzymatically mediated alteration of
drug structure.
Elimination
Combination of metabolism and excretion
Discuss the impact of food on drug absorption, drug metabolism and on
drug toxicity and action—as well as the timing of drug administration.
LIFESPAN
Hepatic metabolism and GFR increase during pregnancy, dosages of
some drugs may need to be increased.
Rate of albumin to water decreases
Third trimester: Renal blood flow is doubled and renal
excretion is accelerated (drugs excreted rapidly)
Tone and mobility of bowel decrease
Prolongation of drug effects Total (½ life increases)
Understand stages of development in pregnancy
, Conception: through week 2
Embryonic period: week 3-week 8
a) Gross malformations can be produced by teratogens
Fetal period: week 9-delivery
Understand pregnancy labeling
3 categories now
a) Pregnancy, lactation, male & female reproductive
potential
How do you decrease risk in the infant during breastfeeding?
Take meds immediately after breastfeeding, avoid drugs that
have long half-lives, choose drugs that tend to be excluded
from milk, avoid drugs that are known to be hazardous.
How do pediatric patients differ in their response to medications?
Absorption
a) Oral?
Neonates: drug remain in the stomach longer
which increases the levels, low acidity can affect
the absorption of acid labile drugs
b) Parenteral?
Reponses are slow and erratic.
Infancy: absorption is more rapid than in neonates
& adults
Best avoided in infants
c) Transdermal?
Greater skin permeability which increases
topical drug absorption and increases the risk
for toxicity
Distribution
a) Protein binding
, 1. Neonates: less protein-binding—increased
availability of highly protein bound drugs such as
phenytoin, diazepam, and phenobarbital. Reduced
dosages needed in these highly bound drugs.
b) Blood Brain Barrier
1. Not fully developed at birth, drugs have easy
access to the CNS, doses should be reduced.
Metabolism
a) Hepatic function?
1. Liver hasn’t reached full maturation—sensitive
to drugs eliminated by the CYP450. Liver’s
ability to metabolize drugs increases about one
month after birth.
b) T half life
1. Decreased by as much as 48-72 hours
Excretion
a) Renal?
1. GFR is significantly reduced at birth, drugs
eliminated by the kidneys must be given in a
reduced dosage and longer dosing intervals.
What education needs to be given to parents?
What to do if child spits out medication or throws it up
Effective education: dosage size and timing, route, technique
of administration, duration of treatment, how to store the
drug, nature and time course of the desired response, nature
and time course of adverse reactions.
Compare and contrast pharmacokinetics and
pharmacodynamics of special populations—pediatrics, older
, adults and those that are pregnant.
Pediatrics—they have organ immaturity, elderly—they have organ
degeneration, loss of nephrons, excretion of drug is decreased and
you have to give this population a lower dose of medication.
Medication can pass through milk of lactating females.
Analyze a drug interaction to determine an appropriate course of action.
Basic mechanism of drug-drug interactions through pharmacokinetic
interactions are altered absorption, altered distribution, altered
metabolism, and altered renal excretion.
Identify medications with a narrow therapeutic index
requiring drug level monitoring.
1.
Discuss the effect of ionization and pH on absorption.
Drugs that are weak acids are best absorbed in acidic environments.
Acidic drugs accumulate on the alkaline side, basic drugs accumulate
on the acidic side known as ion trapping. Ionization of the drugs is
pH dependent, when the pH and the fluid on one side of the
membrane differs from the pH on the other side, drug molecules tend
to accumulate on the side where the pH most favors ionization.
Discuss factors affecting drug distribution.
Competition for protein binding and alteration of extracellular pH
Discuss barriers affecting drug distribution—such as placental
membrane, blood brain barrier and volume of distribution.
Placental membrane: drugs are easily passed through the placental
membrance
Blood brain barrier: the PGP pumps drugs back into the blood and
thereby limits their access to the brain.
Volume of distribution:
Discuss the “first-pass effect”—what effect can this have on distribution
What are the BON rules and regulations for prescriptive authority for
the advance practice nurse?
Texas is very restricted
Describe the pharmacokinetic processes of absorption, distribution,
metabolism and elimination and how differences in these areas affect
drug action.
Absorption
Drug’s movement from the site of administration into the
blood.
Distribution
Drug’s movement from the blood into the interstitial space
of tissues and from there into cells.
Metabolism
Biotransformation is the enzymatically mediated alteration of
drug structure.
Elimination
Combination of metabolism and excretion
Discuss the impact of food on drug absorption, drug metabolism and on
drug toxicity and action—as well as the timing of drug administration.
LIFESPAN
Hepatic metabolism and GFR increase during pregnancy, dosages of
some drugs may need to be increased.
Rate of albumin to water decreases
Third trimester: Renal blood flow is doubled and renal
excretion is accelerated (drugs excreted rapidly)
Tone and mobility of bowel decrease
Prolongation of drug effects Total (½ life increases)
Understand stages of development in pregnancy
, Conception: through week 2
Embryonic period: week 3-week 8
a) Gross malformations can be produced by teratogens
Fetal period: week 9-delivery
Understand pregnancy labeling
3 categories now
a) Pregnancy, lactation, male & female reproductive
potential
How do you decrease risk in the infant during breastfeeding?
Take meds immediately after breastfeeding, avoid drugs that
have long half-lives, choose drugs that tend to be excluded
from milk, avoid drugs that are known to be hazardous.
How do pediatric patients differ in their response to medications?
Absorption
a) Oral?
Neonates: drug remain in the stomach longer
which increases the levels, low acidity can affect
the absorption of acid labile drugs
b) Parenteral?
Reponses are slow and erratic.
Infancy: absorption is more rapid than in neonates
& adults
Best avoided in infants
c) Transdermal?
Greater skin permeability which increases
topical drug absorption and increases the risk
for toxicity
Distribution
a) Protein binding
, 1. Neonates: less protein-binding—increased
availability of highly protein bound drugs such as
phenytoin, diazepam, and phenobarbital. Reduced
dosages needed in these highly bound drugs.
b) Blood Brain Barrier
1. Not fully developed at birth, drugs have easy
access to the CNS, doses should be reduced.
Metabolism
a) Hepatic function?
1. Liver hasn’t reached full maturation—sensitive
to drugs eliminated by the CYP450. Liver’s
ability to metabolize drugs increases about one
month after birth.
b) T half life
1. Decreased by as much as 48-72 hours
Excretion
a) Renal?
1. GFR is significantly reduced at birth, drugs
eliminated by the kidneys must be given in a
reduced dosage and longer dosing intervals.
What education needs to be given to parents?
What to do if child spits out medication or throws it up
Effective education: dosage size and timing, route, technique
of administration, duration of treatment, how to store the
drug, nature and time course of the desired response, nature
and time course of adverse reactions.
Compare and contrast pharmacokinetics and
pharmacodynamics of special populations—pediatrics, older
, adults and those that are pregnant.
Pediatrics—they have organ immaturity, elderly—they have organ
degeneration, loss of nephrons, excretion of drug is decreased and
you have to give this population a lower dose of medication.
Medication can pass through milk of lactating females.
Analyze a drug interaction to determine an appropriate course of action.
Basic mechanism of drug-drug interactions through pharmacokinetic
interactions are altered absorption, altered distribution, altered
metabolism, and altered renal excretion.
Identify medications with a narrow therapeutic index
requiring drug level monitoring.
1.
Discuss the effect of ionization and pH on absorption.
Drugs that are weak acids are best absorbed in acidic environments.
Acidic drugs accumulate on the alkaline side, basic drugs accumulate
on the acidic side known as ion trapping. Ionization of the drugs is
pH dependent, when the pH and the fluid on one side of the
membrane differs from the pH on the other side, drug molecules tend
to accumulate on the side where the pH most favors ionization.
Discuss factors affecting drug distribution.
Competition for protein binding and alteration of extracellular pH
Discuss barriers affecting drug distribution—such as placental
membrane, blood brain barrier and volume of distribution.
Placental membrane: drugs are easily passed through the placental
membrance
Blood brain barrier: the PGP pumps drugs back into the blood and
thereby limits their access to the brain.
Volume of distribution:
Discuss the “first-pass effect”—what effect can this have on distribution
