Test 3: Pediatrics/Autonomic Nervous System

What must be considered for pediatric medication administration?

Age, weight, growth/development stage, organ maturity (liver/kidney), and potential adverse effects.

Key pharmacokinetic differences in neonates/pediatrics?: Absorption

gastric pH higher, slower gastric emptying

Key pharmacokinetic differences in neonates/pediatrics?: Distribution

higher body water, lower fat

Key pharmacokinetic differences in neonates/pediatrics?: Metabolism

Immature liver enzymes → slower drug metabolism

Key pharmacokinetic differences in neonates/pediatrics?: Excretion

immature kidneys → slower drug clearance

How do pharmacokinetic differences create safety concerns?

Higher risk of toxicity, overdosing, prolonged drug effect, or underdosing if not adjusted for weight/age.

How is pediatric IV dose calculated?

Use weight-based formula: mg/kg/dose. Compare to safe min and max dose ranges per day.

How do you calculate IV fluid replacement for pediatrics?

• 100 mL/kg for first 10 kg

• 50 mL/kg for second 10 kg

• 20 mL/kg for each additional kg → divide by 24h for mL/h

How do physiological changes during pregnancy affect pharmacokinetics?

Increased blood volume, renal clearance, altered gastric motility, increased body fat → may change absorption, distribution, metabolism, excretion.

Three key factors affecting drug safety during pregnancy?

1. Drug properties (lipid-soluble, protein-bound, teratogenic)
2. Fetal gestational age (organogenesis = highest risk)
3. Maternal factors (age, kidney/liver function, comorbidities)

What does “risk-benefit ratio” mean in medication during pregnancy/breastfeeding?

Weigh potential benefit to mother against potential harm to fetus or infant.

Sympathetic response

(fight/flight): ↑HR, BP, bronchodilation, pupil dilation, decreased GI motility

Parasympathetic response

(rest/digest): ↓HR, ↑GI motility, ↑secretions, pupil constriction

Five ways drugs can affect synaptic transmission?

1. Increase neurotransmitter release
2. Decrease neurotransmitter release
3. Mimic neurotransmitter (agonist)
4. Block neurotransmitter (antagonist)
5. Inhibit neurotransmitter reuptake or metabolism

direct stimulation

mimics neurotransmitter

indirect stimulation

increases neurotransmitter availability

mixed stimulation

both direct receptor binding and indirect action

Adrenergic agonists (sympathomimetics)

Stimulate sympathetic receptors → ↑HR, BP, bronchodilation; used for shock, asthma, cardiac arrest.

Adrenergic-blocking agents – mechanism and use?

Block sympathetic receptors → ↓BP, HR; used for HTN, angina, arrhythmias.

Cholinergic agonists (parasympathomimetics) – mechanism and use?

Stimulate parasympathetic receptors → ↑GI motility, urination, ↓HR; used for urinary retention, myasthenia gravis, glaucoma.

Cholinergic-blocking agents (anticholinergics) – mechanism and use?

Block parasympathetic receptors → ↑HR, bronchodilation, ↓secretions; used for pre-op, bradycardia, asthma, motion sickness.