Podcast
Questions and Answers
Which factor most significantly affects drug therapy in neonates?
Which factor most significantly affects drug therapy in neonates?
- Increased metabolic enzyme activity compared to adults.
- Immature renal function leading to reduced drug clearance. (correct)
- Enhanced gastrointestinal motility, leading to rapid drug absorption.
- The higher proportion of body fat relative to total body weight.
A drug is primarily metabolized by CYP3A4, CYP2D6 and CYP2C9 enzymes. How would pregnancy affect the clearance of this drug?
A drug is primarily metabolized by CYP3A4, CYP2D6 and CYP2C9 enzymes. How would pregnancy affect the clearance of this drug?
- Clearance may vary depending on the trimester, with no predictable pattern.
- Clearance would significantly decrease due to hormonal changes.
- Clearance would increase, potentially reducing the drug's therapeutic efficacy. (correct)
- There would be no change in clearance due to compensatory mechanisms.
What is the most critical consideration when determining drug dosage adjustments for children compared to adults?
What is the most critical consideration when determining drug dosage adjustments for children compared to adults?
- Children's drug metabolism rates are uniformly faster across all metabolic pathways.
- Paediatric doses are based on extensive clinical trials that mirror adult drug development processes.
- Adult drug doses can be directly scaled down based on body weight for children.
- Children have a proportionally higher total body water content than adults. (correct)
Why are drugs with smaller volumes of distribution (Vd) expected to have lower plasma concentrations (Cp) in neonates?
Why are drugs with smaller volumes of distribution (Vd) expected to have lower plasma concentrations (Cp) in neonates?
What principle guides the selection of drugs for breastfeeding mothers to minimize infant exposure?
What principle guides the selection of drugs for breastfeeding mothers to minimize infant exposure?
A drug shows no evidence of harm in animal studies but has not been studied in pregnant women. According to the Australian Drug Categories, which category does this drug fall into?
A drug shows no evidence of harm in animal studies but has not been studied in pregnant women. According to the Australian Drug Categories, which category does this drug fall into?
A drug is known to cause permanent damage to a foetus and should not be used in pregnancy unless there is no alternative. Which Australian Pregnancy Category does it belong to?
A drug is known to cause permanent damage to a foetus and should not be used in pregnancy unless there is no alternative. Which Australian Pregnancy Category does it belong to?
Which adjustments should be made to the dosages of hydrophilic drugs to account for pharmacokinetic changes in pregnant women?
Which adjustments should be made to the dosages of hydrophilic drugs to account for pharmacokinetic changes in pregnant women?
A drug is solely excreted by glomerular filtration. How would pregnancy affect its clearance?
A drug is solely excreted by glomerular filtration. How would pregnancy affect its clearance?
What consideration should be first and foremost for the safe use of drugs during breastfeeding?
What consideration should be first and foremost for the safe use of drugs during breastfeeding?
If a mother needs treatment, and desires to continue breastfeeding, what general consideration is recommended?
If a mother needs treatment, and desires to continue breastfeeding, what general consideration is recommended?
Which of the following properties are common to drugs that easily cross the placental barrier?
Which of the following properties are common to drugs that easily cross the placental barrier?
How does the higher ratio of total body surface area to body mass in children affect the absorption of topically applied drugs?
How does the higher ratio of total body surface area to body mass in children affect the absorption of topically applied drugs?
What is the primary concern regarding the use of teratogenic drugs during pregnancy?
What is the primary concern regarding the use of teratogenic drugs during pregnancy?
What is a key difference between drug metabolism in neonates compared to adults?
What is a key difference between drug metabolism in neonates compared to adults?
How does the ratio of total body water to body mass in infants and young children affect drug distribution?
How does the ratio of total body water to body mass in infants and young children affect drug distribution?
An expectant mother is prescribed a category C drug. What does this classification imply regarding its use during pregnancy?
An expectant mother is prescribed a category C drug. What does this classification imply regarding its use during pregnancy?
A pregnant woman requires a medication that is known to be actively transported across the placenta. What is a potential risk associated with this?
A pregnant woman requires a medication that is known to be actively transported across the placenta. What is a potential risk associated with this?
Pregnant women often experience decreased gastric acid secretion. How does this change affect the absorption of certain drugs?
Pregnant women often experience decreased gastric acid secretion. How does this change affect the absorption of certain drugs?
The use of ACE inhibitors are more rare during the maturation stage of pregnancy (3- 9 months) in comparison to the organogenesis stage. Why is this the case?
The use of ACE inhibitors are more rare during the maturation stage of pregnancy (3- 9 months) in comparison to the organogenesis stage. Why is this the case?
Medications are often prescribed during pregnancy. Statistically, what percentage of pregnant women will use at least one drug during their pregnancy?
Medications are often prescribed during pregnancy. Statistically, what percentage of pregnant women will use at least one drug during their pregnancy?
When did Dr McBride (NSW, Australia) publish the letter that linked women taking thalidomide in pregnancy to foetal malformations?
When did Dr McBride (NSW, Australia) publish the letter that linked women taking thalidomide in pregnancy to foetal malformations?
Which of the following is NOT a strategy to minimise infant exposure during breastfeeding?
Which of the following is NOT a strategy to minimise infant exposure during breastfeeding?
What factors associated with the mother's body that can have an impact on drugs during pregnancy?
What factors associated with the mother's body that can have an impact on drugs during pregnancy?
Why is determining the right dose of a drug so difficult for neonates?
Why is determining the right dose of a drug so difficult for neonates?
Identify which of the following options is NOT a special population in pharmacology.
Identify which of the following options is NOT a special population in pharmacology.
Which of the following options is NOT a key learning objective for this document?
Which of the following options is NOT a key learning objective for this document?
Which outcome resulted from cases of mothers taking thalidomide?
Which outcome resulted from cases of mothers taking thalidomide?
What best describes Mutagens?
What best describes Mutagens?
What best describes Carcinogens?
What best describes Carcinogens?
Which of the following statements is false?
Which of the following statements is false?
Which of the following properties does NOT fall under the placental transfer of drugs?
Which of the following properties does NOT fall under the placental transfer of drugs?
Many pregnant women suffer from vomiting quite regularly. What does this mean for any drugs that the mother takes?
Many pregnant women suffer from vomiting quite regularly. What does this mean for any drugs that the mother takes?
During pregnancy, there is typically an increase in body fat. What aspect about the fat is correct?
During pregnancy, there is typically an increase in body fat. What aspect about the fat is correct?
During pregnancy, there is typically an increase in plasma volume. What impact does this lead to?
During pregnancy, there is typically an increase in plasma volume. What impact does this lead to?
During pregnancy, what typically occurs to Plasma album concentration?
During pregnancy, what typically occurs to Plasma album concentration?
From the following choices, which one can be described as the safest way to ensure drugs and effective drug use occurs?
From the following choices, which one can be described as the safest way to ensure drugs and effective drug use occurs?
Flashcards
Drug therapy impact factors
Drug therapy impact factors
Specific factors impact drug therapy in neonates, children, and pregnant women. These include physiological changes affecting pharmacokinetics.
Special Populations
Special Populations
Populations needing special drug safety considerations: children, elderly, pregnant women, obese individuals, and those with liver or kidney disease.
Neonate vs. Adult dosing
Neonate vs. Adult dosing
Adult drug doses come from large clinical trials. Pediatric doses are often mg/kg body weight due to physiological differences.
Drug absorption in children
Drug absorption in children
Signup and view all the flashcards
Body-surface area to body mass ratio
Body-surface area to body mass ratio
Signup and view all the flashcards
CYP450 enzyme activity in neonates
CYP450 enzyme activity in neonates
Signup and view all the flashcards
GFR in Newborns
GFR in Newborns
Signup and view all the flashcards
Pregnancy Category A
Pregnancy Category A
Signup and view all the flashcards
Pregnancy Category B
Pregnancy Category B
Signup and view all the flashcards
Pregnancy Category C
Pregnancy Category C
Signup and view all the flashcards
Pregnancy Category D
Pregnancy Category D
Signup and view all the flashcards
Pregnancy Category X
Pregnancy Category X
Signup and view all the flashcards
Pregnancy drug benefit-risk
Pregnancy drug benefit-risk
Signup and view all the flashcards
Effects of Drugs on Embryo
Effects of Drugs on Embryo
Signup and view all the flashcards
Teratogens
Teratogens
Signup and view all the flashcards
Mutagens
Mutagens
Signup and view all the flashcards
Carcinogens
Carcinogens
Signup and view all the flashcards
Fetal Drug Effect Timing
Fetal Drug Effect Timing
Signup and view all the flashcards
Thalidomide Tragedy
Thalidomide Tragedy
Signup and view all the flashcards
Placental Transfer
Placental Transfer
Signup and view all the flashcards
Pregnancy Pharmacokinetics
Pregnancy Pharmacokinetics
Signup and view all the flashcards
Pregnancy effect on liver & kidney function
Pregnancy effect on liver & kidney function
Signup and view all the flashcards
Drugs in Breast Milk
Drugs in Breast Milk
Signup and view all the flashcards
Infant exposure minimisation
Infant exposure minimisation
Signup and view all the flashcards
Study Notes
PHAR3921 2025: Drugs in Pregnancy and Children
- The material discusses the use of drugs in special populations such as neonates, children, pregnant women, and during breastfeeding
Learning Objectives
- To understand the specific factors impacting drug therapy in neonates, children, pregnant women, and the developing foetus
- To describe or predict how physiological changes in these populations affect the pharmacokinetics of administered drugs
- To use this knowledge to suggest methods for the safe and effective use of drugs in these populations
- To discuss methods for the safe use of drugs during breastfeeding
Special Populations in Pharmacology
- Specific considerations are needed to ensure drug safety and efficacy in these populations
- Children (paediatrics)
- Elderly (geriatrics)
- Pregnancy
- Obese
- Disease states (liver disease, kidney disease)
Pharmacokinetics Changes from Neonate to Adult
- Developmental pharmacology involves considering drug disposition, action, and therapy in infants and children
Dosing Considerations for Neonates
- Adult drug doses are based on large clinical trials (population dosing)
- Paediatric drug doses are often expressed as mg/kg body weight
- Neonates and children are not just miniature versions of adults requiring adjustments
Dosing Considerations for Neonates & Children
- GIT motility and oral drug absorption is slow after birth, increasing Tmax
- The ratio of total body surface area to body mass is higher in infants and young children compared to adults
- Caution is needed with topically applied drugs as more of the drug can be absorbed due to the larger surface area
- A higher ratio of total-body water to lipids exists
- Drugs with a smaller Vd will have lower Cp than predicted
- Lower levels of albumin also mean less plasma protein binding
- CYP450 enzyme activity is substantially lower at birth
- Drugs are metabolised much slower, resulting in slower elimination
- Glomerular filtration rate is much lower in newborns
- It increases 50% after one week, reaching adult levels by 6-12 months
- Renal elimination is much lower in the first weeks of life
Prescribing Medicines in Pregnancy: Australian Categories
- Category A: Drugs taken by a large number of pregnant women without proven increase in malformations
- Category B (B1, B2, B3): Drugs taken by a limited number of pregnant women without proven increase in frequency of malformations
- Animal studies show no evidence (B1), lack of evidence (B2), or evidence of foetal damage (relevance to humans?)
- Category C: Drugs that may cause harmful effects on the human foetus or neonate without causing malformations
- Category D: Drugs that have caused or are expected to cause an increased incidence of human foetal malformations
- Category X: Drugs with a high risk of causing permanent damage to the foetus and should not be used during pregnancy
Drug Use in Pregnancy
- Teratogens: Substances that interfere with normal foetal development, causing developmental abnormalities
- Mutagens: Cause genetic mutation and/or increase the mutation rate
- Carcinogens: Cause the development of cancer
Teratogenesis
- Critical periods exist for drug effects on the foetus, impacting organ development
Thalidomide Tragedy
- In 1961, Dr McBride (Australia) reported a link between thalidomide use in pregnancy and foetal malformations
- Originally marketed as a safe hypnotic (sedative), even for morning sickness
- Caused phocomelia (impaired development of long bones in arms and legs)
- Estimated to have caused malformations in over 10,000 babies
Predicting placental transfer of drugs
- Small molecular size and weight (MW<600)
- Not plasma protein bound
- Non-ionised
- Lipophilic
Maternal Pharmacokinetics
- Frequent vomiting may prevent oral administration or result in unpredictable Cp after oral administration
- Some evidence of decreased gastric acid production, slower gastrointestinal motility
- Distribution altered with increased body fat (25%) increasing fat reservoir, and increased plasma volume (42%) decreasing Cp
- Plasma albumin concentration decreases (20%), decreasing plasma protein binding
- CYP3A4, CYP2D6 and CYP2C9 activity is increased in pregnancy
- GFR is 50% higher than average in the first trimester and continues to increase through to term
- Renal clearance is expected to increase for drugs excreted by glomerular filtration
- Example: clearance for Lithium is doubled during the third trimester
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
