Chapter 9 - Pharmacotherapy of the Pediatric Patient

Question 1

• Pediatric Care

Answer 1

• Body systems are in a constant state of development
• Effects of drugs can often be unpredictable

Question 2

Pediatric - Distribution of drug classes different

Answer 2

• While cardiovascular drugs are readily prescribed for adults, pediatrics prescribed more respiratory, anti-infectives
• Antibiotics are most common followed by drugs for asthma
• ADHD in older chuildren

Question 3

Before 1990s - Limited drug information

Answer 3

• Pediatric drug trials rare
• Data for Pharmacokinetics, ADR are not well documented
• Most pediatric drugs not available/compatible with neonates/infants
• Drugs that were found effective in adults are assumed to be effective for children

Question 4

FDA Modernization Act

Answer 4

• Passed in 1997, drug sponsors provided financial incentives to conduct pediatric pharmacology research
• In exchange, pharmaceutical companies gave extension of 6 months of exclusivity
• 1998‒2012
  
  • 173 (92%) received new pediatric labeling information
  • 108 (57%) given new or expanded pediatric indication
• Better informs healthcare providers on safety and efficacy

Medications chosen based on their ability to extend exclusivity rather than to benefit children

Act gave no incentives for studying generic drugs or those with a smaller market.

Question 5

Best Pharmaceuticals For Children Act (BPCA)

Answer 5

• 2002 authorized the FDA to contract for testing of already approved pediatric drugs or when pharma ycompany declines option of exclusivity

Question 6

Pediatric Research Equity Act of 2003 (PREA)

Answer 6

• Gave FDA authorization to require research into pediatric use for new drugs
• Extended to biologics in 2010
• Led to pediatric labeling changes
• Today, vaccines/antibiotics have adequate labels for pediatrics.
• HIV, GI Disorders, Pain, HTN, steroids medications still have limited pediatric information.

Question 7

Pediatric Pharmacokinetic Variables - Absorption

Answer 7

Growth and development affect the mechanisms of pharmacodynamics and pharmacokinetics

• Absorption -
  
  • Increased gastric pH and delayed gastric emptying
    
    • keep drug in system longer and increase absorption across stomach mucosa BUT slow drugs that rely on intestinal absorption
  • Low gastric acid production may enhance absorption of acid-labile drugs such as ampicillin and penicillin AND slow weak acids
    
    • Acid production reached adult level at 2-3
• Bile salt secretion is diminished in infants and neonates - delays absorption of lipid-soluble drugs and vitamins
• Low blood flow to muscles - slow and erratic absorption of intramuscular (IM) and subcutaneous.
• Skin highly permeable - absorption is faster

Question 8

Pediatric Pharmacokinetic Variables: Distribution

Answer 8

3 factors effects:

• Infants of body weight is 80% water
  
  • Gradually decreases over first year
  • Dilutes water-soluble drugs
  • Serum move to other parts of the body with higher water concentration
  • May need higher dose of serum to maintain adequate levels
  • Low body fat - lipid soiuble drugs tend to stay in the blood, raising serum drug levels
• Immature liver function - produces small amounts of plasma proteins
  
  • Drugs that mind to plasma proteins present as “free” drugs in serum
• Underdeveloped blood-brain barrier

Question 9

Pediatric Pharmacokinetic Variables: Metabolism

Answer 9

• Impacted by the immaturity of the hepatic cytochrome P450 (CYP450) enzyme system
• Significantly slower in children, reduced clearance rates and extended half-lives
• Metabolic rate reaches adult levels buy ages 3-5 years
• Especially sensitive to benzyl alcohol

Question 10

Pediatric Pharmacokinetic Variables: Excretion

Answer 10

• Depends on the maturity and function of the kidneys
  
  • young children have immature renal systems with slower renal clearance
  • accumulation of drugs excreted by the kidneys
  • At risk for nephrotoxicity

Question 11

Pharmacologic Implications with Growth and Development

Answer 11

• Consider age, weight, and developmental level.
• For medication administration - pediatric patients defined as
  
  • birth-16 years and weigh less than 50 kg (110 lb)
• Take necessary precautions based on infant, toddler, preschooler, school-age and adolecent

Question 12

Medication Safety for Pediatric Patients

Answer 12

• Accurate drug dosage calculations, proper administration techniques, proper efforts to minimize adverse drug reactions, and overall safety cannot be overemphasized.
• Medication safety is a team approach similar to adults.
• Most hospitals require double-checking drugs with another nurse (Heparin, Lanoxin, Insulin, barbiturates, opiates analgesics and chemotherapeutic agents).
• Nursing education and communication - provide education for patient/caregiver regarding administration.
• Record/verify patient identity, weight, allergies, previous medication use.
  
  • Be involved in ongoing error-tracking systems and encourage blame-free error reporting.

Question 13

Determining Pediatric Drug Dosages

Answer 13

• Nurse must consistently update calculation skills
• Drug dosage calculations should consider child’s age, height, weight, maturational state, and body surface area.
• All critical care medications should be double-checked.
• Two common procedures of calculating pediatric dosages:
  
  • Body weight method
    
    • Calculate drug milligrams based on child’s weight in kg. Unit of time usually included.
      
      • Method simple, and dose can be quickly calculated.
      • ex. gentamicin 5 mg/kg/24 h
  • Body surface area (BSA) method
    
    • Accounts for pharmacokinetic differences. believed to be the most valid
    • Estimates blood volume, metabolism, and effects of drugs.
    • Online BSA calculators available.

Question 14

ADR in Children

Answer 14

• Smaller size and immature or developing organs in children put at higher risk for ADR.
• Identifying ADR depends on skill of assessor
• Infants and young children do not have the maturity or verbal skills to accurately describe feelings.
• Most ADR in children age 1 or older are same as in adults.
• Majority of adverse effects are dose related.
• Pay close attention to proper dose/frequency of drug administration.
• Few types of adverse effects specific to children. Often result of immature or developing organs and tissues.