Standard mg/kg dosing with adult-max safety cap.
Computes weight × mg/kg with optional adult-max cap.
Enter values to see the result.
Formula: Dose (mg) = weight (kg) × mg/kg per dose. Cap at adult maximum if exceeded.
Always verify against medicine-specific pediatric prescribing guidelines. Some medicines require fixed maxima well below adult max.
Pediatric patients are not small adults — a statement that may seem self-evident but reflects a profound pharmacological reality that has been hard-won through decades of pediatric medicine safety research. The physiological differences between neonates, infants, toddlers, school-age children, and adolescents are so significant that virtually every pharmacokinetic parameter — absorption, distribution, metabolism, and elimination — differs meaningfully from adults, and differs differently across pediatric age groups relative to each other.
The history of pediatric pharmacology includes sobering examples of the consequences of treating children as small adults. The chloramphenicol "gray baby syndrome" of the 1950s and 1960s, in which neonates given adult-weight-proportional doses of chloramphenicol developed fatal cardiovascular collapse, was traced to the immature glucuronyltransferase enzyme systems in neonates that could not adequately conjugate and eliminate the medicine. Accumulation of chloramphenicol to toxic plasma concentrations caused the characteristic ashen-gray skin color, abdominal distension, hypotonia, and cardiovascular collapse from which the syndrome takes its name.
Sulfonamide toxicity in neonates — causing kernicterus (bilirubin encephalopathy) by displacing bilirubin from albumin binding sites — was another early lesson in neonatal pharmacology. More recently, codeine toxicity in children, including reported deaths in ultrarapid CYP2D6 metabolizer children who were prescribed codeine for post-tonsillectomy pain, led the FDA to contraindicate codeine in children under 12 years and in nursing mothers, and to issue strong warnings about use in children 12-18 with obstructive sleep apnea.
The fundamental rationale for weight-based dosing is that medicine clearance — the primary pharmacokinetic parameter determining medicine exposure — correlates better with body weight (or, for some medicines, with body surface area) than with chronological age. A 20 kg, 6-year-old child has approximately 40% of the renal mass and 35% of the hepatic mass of a 70 kg adult; their total medicine-metabolizing and medicine-eliminating capacity scales roughly with body size. Administering a fixed dose calculated for an average adult to a 20 kg child would result in approximately 3-4 times the intended medicine exposure, with proportionally elevated toxicity risk.
Body surface area (BSA)-based dosing is used for certain medicines — primarily chemotherapy agents — where empirical pharmacokinetic data shows better dose normalization with BSA than with weight. The argument for BSA-based dosing is that glomerular filtration rate and cardiac output, two key determinants of medicine clearance, scale more closely with BSA than with body weight alone. For most common pediatric medications (antibiotics, antipyretics, anticonvulsants), mg/kg dosing is the standard approach and provides adequate dosing precision.
The basic framework for pediatric weight-based dosing involves four sequential steps: (1) obtain an accurate body weight in kilograms; (2) calculate the per-dose amount using the published mg/kg/dose value; (3) apply the maximum dose cap (the dose should never exceed the standard adult dose regardless of calculated weight-based amount); and (4) determine the dosing frequency (interval) and, if applicable, the daily total dose.
Obtaining accurate weight is the critical first step and the most important error-prevention measure. Errors in pediatric medicine dosing most commonly originate from weight estimation errors, weight unit confusion (kilograms vs. pounds), and decimal point errors. A 10-fold overdose in a 10 kg toddler may involve milligram quantities physically indistinguishable from the correct dose in a syringe. The Joint Commission identified pediatric weight in kilograms as a National Patient Safety Goal, requiring that all pediatric inpatients have a documented weight in kilograms — not pounds — at every encounter. In emergencies where weight measurement is impossible, the Broselow tape (a length-based weight estimation tool with color-coded weight bands) provides a validated weight estimate and pre-calculated medicine doses.
Maximum dose caps are absolute constraints that must be applied regardless of the weight calculation result. A 60 kg adolescent calculating a 10 mg/kg amoxicillin dose for streptococcal pharyngitis would mathematically receive 600 mg per dose — which, while within some dosing guidelines, would exceed the standard 500 mg adult dose cap recommended for non-severe pharyngitis in most references. Failing to apply the adult maximum dose cap to a large adolescent is a common pediatric dosing error.
Dosing frequency (intervals between doses) is determined by the medicine's pharmacokinetics — primarily its half-life and the relationship between its concentration-time curve and pharmacodynamic effect. Concentration-dependent antibiotics (aminoglycosides, fluoroquinolones) achieve maximal kill rate when peak concentrations are high, favoring once-daily or twice-daily dosing; their effectiveness is proportional to Cmax/MIC. Time-dependent antibiotics (beta-lactams, vancomycin, macrolides) require maintenance of plasma concentrations above the minimum inhibitory concentration (MIC) for a proportion of the dosing interval, favoring more frequent dosing or continuous infusion. Pediatric dosing intervals are often shorter than adult intervals for equivalent medicines because children generally have higher weight-normalized clearance rates, particularly in the toddler and school-age years.
Divided doses (twice daily, three times daily, four times daily) are calculated from the total daily dose. When a reference specifies a total daily dose in mg/kg/day (e.g., amoxicillin 40 mg/kg/day divided every 8 hours), the per-dose amount is the daily total divided by the number of daily doses. For amoxicillin in a 20 kg child at 40 mg/kg/day divided TID: Daily dose = 20 × 40 = 800 mg/day; per-dose = 800 ÷ 3 = 267 mg per dose (rounded to the nearest commercially available concentration or tablet strength). The same medicine may be prescribed with different divided dose instructions for different indications (e.g., amoxicillin 40 mg/kg/day divided BID for otitis media, vs. 45 mg/kg/day divided TID for severe pneumococcal infection).
| Age | Avg Weight (kg) | Avg Weight (lb) | Notes |
|---|---|---|---|
| Newborn (term) | 3.5 | 7.7 | Birth weight doubles by ~5 months |
| 1 month | 4.5 | 9.9 | Rapid weight gain phase |
| 3 months | 6.2 | 13.7 | ~2× birth weight by 4-5 months |
| 6 months | 7.8 | 17.2 | Solid foods introduction |
| 9 months | 9.2 | 20.3 | Approaching 3× birth weight |
| 12 months (1 year) | 10.0 | 22.0 | ~3× birth weight; gains ~2-3 kg/year next 3 years |
| 18 months | 11.5 | 25.4 | |
| 2 years | 13.0 | 28.7 | Weight ≈ (age in years + 4) × 2 kg for rough estimate |
| 3 years | 14.5 | 32.0 | |
| 4 years | 16.5 | 36.4 | |
| 5 years | 18.5 | 40.8 | |
| 6 years | 21.0 | 46.3 | |
| 7 years | 23.0 | 50.7 | |
| 8 years | 26.0 | 57.3 | |
| 10 years | 32.0 | 70.5 | |
| 12 years | 40.0 | 88.2 | Puberty onset variable |
| 14 years (F) | 52.0 | 114.6 | Female growth spurt earlier |
| 14 years (M) | 50.0 | 110.2 | Male growth spurt later |
| 16 years (F) | 57.0 | 125.7 | Near adult weight |
| 16 years (M) | 62.0 | 136.7 | Continues gaining into early 20s |
| 18 years | 65–70 | 143–154 | Approaching adult values |
WHO/CDC growth reference values (50th percentile). Actual weights vary; always weigh the patient — do not dose from estimated weights unless emergency.
| Medicine | Indication | Dose (mg/kg) | Frequency | Max Dose | Age Limit |
|---|---|---|---|---|---|
| Acetaminophen | Fever/Pain | 10–15 mg/kg/dose | Q4–6h | 1000 mg/dose; 75 mg/kg/day | All ages |
| Ibuprofen | Fever/Pain/Inflammation | 5–10 mg/kg/dose | Q6–8h | 400–600 mg/dose | ≥6 months |
| Amoxicillin | Otitis media, pharyngitis | 40–45 mg/kg/day | Divided BID or TID | 500 mg/dose (standard) | All ages |
| Amoxicillin (High-dose) | AOM (resistant strains) | 80–90 mg/kg/day | Divided BID | 4 g/day | All ages |
| Amoxicillin-clavulanate | AOM, sinusitis, skin/soft tissue | 40–45 mg/kg/day (amox) | Divided BID (ES-600 formulation) | 875 mg/dose | ≥2 months |
| Azithromycin | CAP, strep pharyngitis | 10 mg/kg day 1, then 5 mg/kg days 2–5 | Once daily | 500 mg day 1; 250 mg days 2–5 | ≥6 months |
| Metronidazole | C. diff, anaerobic infections, giardia | 7.5 mg/kg/dose (TID) | TID (Q8h) | 500 mg/dose; 2 g/day | All ages |
| Cefdinir | AOM, pharyngitis, skin infections | 7 mg/kg/dose BID or 14 mg/kg once daily | BID or QD | 300 mg/dose BID; 600 mg/day | ≥6 months |
| Prednisolone | Asthma exacerbation, croup | 1–2 mg/kg/day | Once daily or divided BID | 40–60 mg/day | All ages |
| Albuterol (nebulized) | Asthma/bronchospasm | 0.15 mg/kg/dose (min 2.5 mg) | Q20 min × 3, then Q1–4h PRN | 5 mg/dose | All ages |
| Ondansetron | Nausea/vomiting | 0.1–0.15 mg/kg/dose | Q8h PRN | 4 mg (child); 8 mg (adult) | ≥6 months |
| Diphenhydramine | Allergic reaction, sedation | 1 mg/kg/dose | Q6h | 50 mg/dose | ≥2 years; avoid <2yr |
Reference doses for common indications. Verify with current references (Nelson's Pediatric Antimicrobial Therapy, Harriet Lane Handbook) before prescribing. Doses may vary by indication severity.
Oral medicine absorption in neonates and young infants differs substantially from older children and adults due to developmental differences in gastrointestinal physiology. Gastric pH in neonates is relatively alkaline at birth (pH 6–8), then falls to adult acid values (pH 1–3) within 24-48 hours, then gradually re-alkalinizes over the first 2-3 months of life before normalizing. This higher gastric pH affects medicines that are acid-labile (ampicillin, penicillin G — better absorbed in neonates) versus acid-dependent for dissolution (ketoconazole, itraconazole — poorly absorbed in neonates). Gastric emptying time is prolonged in neonates (up to 6-8 hours vs. 1-3 hours in adults), delaying peak plasma concentrations of orally administered medicines. Intestinal motility is generally lower, further prolonging absorption.
Total body water is substantially higher as a percentage of body weight in neonates (75-80% of body weight) compared with adults (55-60%), and the proportion decreases progressively throughout childhood. This expanded total body water means that water-soluble (hydrophilic) medicines — aminoglycosides, beta-lactam antibiotics, vancomycin — have a larger volume of distribution in neonates and young infants, requiring higher mg/kg doses to achieve equivalent plasma concentrations. Plasma protein binding is reduced in neonates due to lower albumin levels, lower total protein concentration, and competition from fetal albumin (which has lower affinity for medicines), bilirubin, and free fatty acids. Reduced protein binding means higher free medicine fractions, increasing both pharmacological activity and toxicity risk for highly protein-bound medicines.
Hepatic CYP450 enzyme systems are incompletely developed at birth, with significant immaturity in both expression and activity of major medicine-metabolizing isoforms. CYP3A7 (expressed predominantly in fetal liver) rapidly gives way to CYP3A4 (the dominant adult isoform) after birth, but CYP3A4 activity doesn't reach adult levels until 6-12 months of age. CYP1A2 is nearly absent at birth and doesn't reach adult activity until 1-3 years. CYP2D6 matures by 2-3 years. Phase II conjugation reactions — glucuronidation, sulfation, acetylation — also mature at different rates, with glucuronidation (important for morphine, acetaminophen, chloramphenicol, and bilirubin) being most significantly immature in neonates.
Glomerular filtration rate (GFR) at birth is approximately 20-30% of adult values (corrected for body surface area), primarily because neonatal nephrons are not fully mature at birth and blood pressure driving glomerular filtration is lower. GFR increases rapidly over the first 2 weeks of life, reaches approximately 50% of adult values by 6 weeks, and achieves adult values (corrected for BSA) by 1-2 years of age. Tubular secretion and reabsorption also mature more slowly than glomerular filtration. The clinical implication is that renally-cleared medicines — aminoglycosides, vancomycin, penicillins, cephalosporins — have substantially longer half-lives in neonates and young infants, requiring extended dosing intervals (e.g., gentamicin once every 48 hours in premature neonates, vs. once every 24 hours in term neonates, vs. every 8 hours in older children).
Certain medication categories are associated with a disproportionate risk of serious adverse events in pediatric patients, often due to the small doses involved (magnifying the impact of decimal point errors), unique pediatric metabolic vulnerabilities, or lack of pediatric-specific formulations requiring compounding.
Concentrated electrolyte solutions — particularly concentrated potassium chloride (2 mEq/mL and 3 mEq/mL concentrations), hypertonic saline (3% NaCl), and concentrated dextrose solutions — are implicated in numerous preventable pediatric deaths from medication errors. These solutions should be stored separately from standard IV fluids, require independent double-checks before administration, and should be diluted prior to IV infusion. The Institute for Safe Medication Practices (ISMP) designates concentrated electrolytes as High-Alert Medications and recommends removing concentrated KCl from floor-stock in pediatric and adult units alike.
Acetaminophen overdose is the most common cause of acute liver failure in children in the United States, and a significant proportion of cases are unintentional — occurring when caregivers administer doses more frequently than recommended (stacking doses) or use multiple acetaminophen-containing products simultaneously (acetaminophen in a cough/cold formulation plus a separate antipyretic). The maximum safe total daily acetaminophen dose in children is 75 mg/kg/day or 4 grams/day (whichever is less). In infants under 3 months, acetaminophen use requires physician guidance due to immature glucuronidation capacity.
Insulin is a high-alert medication in all patients, but in non-diabetic pediatric patients requiring insulin infusions (hyperkalemia management, hyperosmolar states, or critical illness-related hyperglycemia), the risk of iatrogenic hypoglycemia is dramatically elevated. Insulin 1 unit/mL concentration requires careful dilution and pump programming, and glucose must be monitored at minimum every 30-60 minutes during insulin infusion in children. Anticoagulants (heparin, enoxaparin, warfarin) require weight-based dosing with close monitoring; pediatric heparin protocols use different anti-Xa target ranges and dosing algorithms than adult protocols.
The majority of medications used in pediatric clinical practice have not been studied in children through formal FDA-approved clinical trials. Historically, pharmaceutical companies had limited financial incentive to conduct costly pediatric pharmacokinetic and efficacy studies for medications already approved in adults, resulting in a situation where most medicines were prescribed to children "off-label" — outside the age, weight, or indication specified in the FDA-approved package insert.
Two major pieces of US legislation were enacted to address this gap. The Best Pharmaceuticals for Children Act (BPCA, 2002) provides pharmaceutical companies with financial incentives (patent exclusivity extensions) for conducting FDA-requested pediatric studies. The Pediatric Research Equity Act (PREA, 2003, made permanent in 2012) requires manufacturers of new molecular entities and new indications to assess safety and efficacy in relevant pediatric age groups. These laws have resulted in the pediatric study of hundreds of medications over the past two decades, leading to new pediatric labeling, dose recommendations, and identification of unexpected pediatric-specific safety signals (e.g., increased suicidality risk with antidepressants in adolescents).
Despite this progress, a substantial gap remains. Off-label use of medications in neonates and infants is estimated to exceed 90% in neonatal intensive care units. This reality underscores the importance of using validated pediatric dosing references — the Harriet Lane Handbook, Nelson's Pediatric Antimicrobial Therapy, the Lexicomp Pediatric and Neonatal Lexi-Medicines database, and Micromedex — rather than scaling adult doses without pharmacokinetic justification.
All published pediatric medicine doses are expressed in mg per kilogram (mg/kg). Using pounds in calculations without converting to kilograms introduces a 2.2-fold error — a child's weight in pounds is 2.2 times their weight in kilograms, so dosing in pounds without conversion results in a 2.2-fold overdose. This error has caused preventable deaths and is a sentinel event in pediatric medication safety. Always document and dose using kilograms, and prominently label the patient's weight in kilograms on their medical record and medication administration record.
The Broselow pediatric emergency tape is a length-based color-coded resuscitation tool used when accurate weight measurement is not possible — primarily in pediatric emergencies. The tape is laid along the child's body from head to heel, and the child's length corresponds to a color zone that provides pre-calculated medicine doses, equipment sizes (endotracheal tube, laryngoscope blade, IV catheter), and defibrillation energy settings. Studies show the Broselow tape provides weight estimates accurate enough for emergency medicine dosing in approximately 75-85% of children. It is less accurate at extremes of weight (very obese or very malnourished children) and should be replaced by an actual weight measurement as soon as the emergency situation is stabilized.
Ibuprofen is dosed at 5-10 mg/kg per dose in children ≥6 months of age, given every 6-8 hours as needed. The maximum single dose is 400 mg for antipyretic/analgesic use (600 mg for anti-inflammatory use in older children under medical supervision). The maximum daily dose is 40 mg/kg/day, not exceeding 2400 mg/day. Ibuprofen should be avoided in children under 6 months, in children with dehydration or reduced fluid intake (increased risk of acute kidney injury), in children with varicella (association with necrotizing fasciitis), and in children with known renal, hepatic, or bleeding disorders.
The recommended dosing for acetaminophen in children is 10-15 mg/kg per dose (some guidelines use up to 15 mg/kg), given every 4-6 hours as needed. The maximum daily dose is 75 mg/kg/day, not exceeding 4 grams/day (whichever is lower). Dosing frequency should not exceed 5 doses in 24 hours. Critical safety points: do not use multiple acetaminophen-containing products simultaneously; use age/weight-appropriate liquid concentrations (the 160 mg/5 mL infant/children's formulation has largely replaced the older 100 mg/mL concentrated infant drops to reduce overdose from concentration confusion); and do not exceed 5 days of use for pain or 3 days for fever without medical evaluation.
Aspirin is contraindicated for fever management in children under 18 years due to the well-established association between aspirin use during viral illnesses (influenza, varicella) and Reye's syndrome — a rare but potentially fatal condition causing liver failure and encephalopathy. This contraindication has been in place since the early 1980s following epidemiological studies firmly establishing the association, and it led to the dramatic decline in Reye's syndrome incidence. Aspirin does have specific pediatric indications (Kawasaki disease treatment, certain cardiac conditions) under physician supervision, but antipyretic use in children should be limited to acetaminophen and ibuprofen (age ≥6 months).
Amoxicillin is a time-dependent antibiotic that requires plasma concentrations to exceed the MIC for at least 40-50% of the dosing interval for bactericidal activity. Twice-daily (BID) dosing of high-dose amoxicillin (80-90 mg/kg/day divided BID) is used for acute otitis media (AOM), particularly for suspected penicillin-resistant pneumococcal strains. Three-times-daily (TID) dosing at standard doses (40 mg/kg/day) is used for streptococcal pharyngitis. The trend in pediatric infectious disease guidelines has generally moved toward BID amoxicillin regimens where appropriate to improve adherence, as caregivers find BID schedules substantially easier to comply with than TID regimens.
The FDA recommends against use of OTC cough and cold medications in children under 4 years, and many clinicians extend this recommendation to children under 6. Multiple cases of serious adverse events — including deaths from antihistamine toxicity, paradoxical CNS stimulation, and cardiovascular effects — have been reported in young children given OTC cold preparations. These medications contain combinations of antihistamines (diphenhydramine, chlorpheniramine), decongestants (pseudoephedrine, phenylephrine), cough suppressants (dextromethorphan), and expectorants (guaifenesin). In young children, the therapeutic window is narrow, dosing guidance is unreliable, and evidence for clinical efficacy in children is weak. Saline nasal drops and suctioning, humidified air, and adequate hydration are preferred approaches for viral upper respiratory tract infections in young children.
Dosing for obese children (BMI ≥ 95th percentile for age/sex) presents challenges analogous to those in obese adults. For most medications, actual body weight is used up to the adult maximum dose — the dose cap prevents excessive dosing even when calculated weight-based doses would exceed adult doses. For specific medicines with known altered pharmacokinetics in obesity (aminoglycosides, vancomycin, some antifungals), adjusted or ideal body weight may be more appropriate. Consultation with a clinical pharmacist is recommended for high-risk medications in significantly obese pediatric patients, and therapeutic medicine monitoring (where available) should be used to guide dosing.
The Holliday-Segar formula calculates estimated daily fluid maintenance requirements based on body weight: 100 mL/kg/day for the first 10 kg of body weight, plus 50 mL/kg/day for the next 10 kg (11-20 kg), plus 20 mL/kg/day for each kilogram above 20 kg. Example for a 25 kg child: (10 × 100) + (10 × 50) + (5 × 20) = 1000 + 500 + 100 = 1600 mL/day, or approximately 67 mL/hr. This formula is an estimate of insensible losses plus normal output requirements; actual fluid needs vary substantially with fever (increase ~10% per 1°C above 37°C), surgical losses, vomiting, diarrhea, and renal/cardiac disease.
The most widely used and authoritative pediatric medicine dosing references include: the Harriet Lane Handbook (published by Johns Hopkins, updated regularly — comprehensive and practical); Nelson's Pediatric Antimicrobial Therapy (specifically for infectious disease medications); the Lexicomp Pediatric and Neonatal Lexi-Medicines database (evidence-graded, regularly updated, pharmacy standard); Micromedex (clinical pharmacology and dosing resource); and the Red Book (American Academy of Pediatrics, for infectious disease guidance). Online resources including UpToDate and the AAP's institutional guidelines also provide current, evidence-based pediatric dosing recommendations. Never dose pediatric patients based solely on adult dosing scaled by weight without verifying against a dedicated pediatric reference.
Children are not simply small adults — they have fundamentally different physiology that affects medication absorption, distribution, metabolism, and excretion. Pediatric pharmacology recognizes that pharmacokinetics and pharmacodynamics change dramatically across developmental stages, requiring specialized expertise and careful dosing approaches. The Academy of Pediatrics, World Health Organization, and FDA have established frameworks specifically for pediatric medication use, recognizing that adult studies cannot simply be extrapolated to children.
Developmental pharmacology research has revealed striking age-dependent variations in drug handling. Neonates have immature liver enzymes, low protein binding, and high body water content. Infants experience rapid maturation of metabolism between birth and 2 years. Young children may metabolize some drugs faster than adults due to higher relative liver mass. Adolescents face the challenges of puberty-induced hormonal changes affecting drug metabolism. Each developmental stage requires age-appropriate dosing strategies.
Standard pediatric age categories used in dosing guidelines:
Pediatric medications are typically dosed in one of three ways: weight-based (mg/kg), age-based, or BSA-based (mg/m²). Each method has advantages and limitations.
Weight-based dosing (mg/kg) is most common in clinical pediatrics. It's simple to calculate and adjust as the child grows. However, very small children and adolescents present challenges — small children may need higher mg/kg doses due to differences in body composition, while adolescents approaching adult size may benefit from capping weight-based doses at adult maximums.
Body Surface Area dosing (mg/m²) is preferred for many oncology drugs, some immunosuppressants, and certain antibiotics. BSA better approximates metabolic rate and is more consistent across ages. The Mosteller formula (BSA = √(height in cm × weight in kg / 3600)) is most commonly used. However, BSA calculations have errors in obese children and infants, and the additional calculation step introduces potential for error.
Age-based dosing is used for certain over-the-counter medications and some specific clinical situations. It's simple but can be inaccurate when children's weights vary significantly from age-typical values.
While always referring to current clinical references and the child's specific situation, here are commonly used pediatric medications with typical doses:
Antibiotics:
Pain and Fever:
Asthma Medications:
Allergy Medications:
Pediatric medication errors occur at higher rates than adult errors and can have devastating consequences. Common error sources include:
Best practices for pediatric medication safety include double-checking calculations, using metric measurements consistently, verifying weights and units, using appropriate dosing devices (oral syringes for liquid medications), considering electronic prescribing with dose limits, and providing clear written instructions to caregivers.
Liquid medications are common in pediatrics due to swallowing difficulties with solid forms. However, liquid medications have unique challenges:
Premature Infants and Neonates: Newborn pharmacology is highly specialized. Premature infants in NICUs receive individualized dosing based on gestational age, postnatal age, weight, and organ function. Many medications have specific neonatal dosing protocols.
Children with Renal Impairment: Many medications require dose adjustment based on creatinine clearance. The Schwartz formula (height-based) is commonly used for estimating GFR in children. Pediatric nephrologists provide guidance for children with chronic kidney disease.
Children with Liver Disease: Liver disease affects metabolism of many medications. Dose reductions, alternative agents, or specialized monitoring may be needed.
Children with Genetic Differences: Pharmacogenomic differences can dramatically affect drug response. CYP2D6 ultrarapid metabolizers face increased toxicity from codeine; poor metabolizers experience reduced analgesia from codeine. Similar genetic considerations affect many other medications.
Obese Children: Childhood obesity creates dosing challenges similar to adults. Lean body weight may be more appropriate than total body weight for some medications. Discussions with clinical pharmacists are valuable for complex cases.