Pediatric Considerations
Pharmacokinetics
Absorption
- Neonates have less developed absorption than adolescents
- Changes in absorption in adolescents are due to hormonal, nutritional, and physical changes or habits
- The ratio of body surface area-weight is substantially higher than in adults which means drugs are more readily absorbed and can lead to toxicity
GI Absorption
Because neonates are underdeveloped, their GI absorption of medications are also delayed or hindered.
- Gastric pH is alkaline at birth
- Acid production begins in the neonatal period
- Intestinal surface area in neonates does not reach adult levels until 20 weeks old
- Gastric emptying times in neonates and infants are unpredictable. The emptying times reach adult levels between 6-8 months of age
- Breastfed babies have faster emptying times than formula-fed babies
- Gastric acid secretions reach adult levels around 2 or 3 years old
- Neonates have difficulty absorbing lipid-soluble medications because their pancreatic enzymes and production of bile salts are underdeveloped
Distribution
- Within the first year of life, infants have decreased protein concentrations and fewer drug receptor sites, which means there is a greater unbound drug concentration in the blood
- Increased risk for toxicity
- Neonates and infants have about 75% body water compared to an adult's 60%
- Drug concentrations are diluted and need higher dosing of water-soluble drugs to reach therapeutic levels
- This consideration is necessary until the infant is around 2 years old
- The BBB in neonates is immature and allows drugs to pass easily
Metabolism
- Hepatic blood flow is reduced in infants until approximately 1 year of age, which is when the blood flow would equal an adult's
- Hepatic metabolic enzymes (P450 system) will not reach adult levels until 11 years old
Excretion
- The GFR of neonates is 30% of an adult's
- Increased risk for drug toxicity by retention
- By the time the child reaches 1 year old, their glomerular filtration rate reaches adult levels
Considerations by Age
0-1 Year
- Intestinal surface area in neonates does not reach adult levels until 20 weeks old
- Gastric emptying times reach adult levels between 6-8 months of age
- Within the first year of life, infants have decreased protein concentrations and fewer drug receptor sites, which means there is a greater unbound drug concentration in the blood
- When the child turns 1 year old, their GFR is that of an adult's
- Hepatic blood flow is reduced until a child turns 1
2-3+ Years
- Children up until 2 have ~75% body water compared to an adult
- Gastric acid secretions reach adult levels by 2-3 years of age
- Hepatic drug metabolizing enzymes do not reach adult levels until the child is around 11 years old
Nursing Implications
Oral
-Most pediatric drugs are administered orally
- Least invasive
- Caretakers can administer
- Topical, rectal, and parenteral routes are used when oral route are contraindicated
- IV is used more because of tissue differences among children
- Most oral drugs given to kids under 6 are administered with an oral syringe
- The syringe is pointed toward the buccal mucosa on either side of the mouth
- Pointing the syringe to the back of the throat increases the risk of aspiration
- Pointing the drug too close to the front of the mouth increases the chances of the medicine being spit out
- Some drugs can be made tastier with jams, honey, or yogurt
- Children under 1 cannot have honey because of the risk of botulism
Oral Route Variability by Age
| Age | Dosage Form |
| Neonate (0-4 Weeks) |Indication dependent
| Infant (1 Month-2 Years) | Small-volume liquids (syrups/solutions)
| Children (2-5 Years) | Liquids, tablets dispersed in liquid, sprinkles on food
| Children (6-11) | Solids (chewable, orally disintegrating, oral films)
| Adolescents (12-18 Years)| Solids (tablets/capsules)
IV
- Iv infusion sites must be protected from infants and toddlers who don't understand the importance of maintaining the site
- Sleeves and stockings can be used to hide the site
- Colorful bandages should be used with preschoolers over the sites so they do not fear the leakage
- IV sites may difficult to find in children due to hydration status, fatty tissue, and the ability to isolate and immobilize veins
### IM & SQ
- Ventrogluteal and vastus lateralis are preferred sites
- Needle length depends on muscle mass, subcutaneous tissue, and the site of injection
- Children may prefer leg or upper arm rather than abdominal sites for SQ injections