What are the appropriate doses of different medications, such as acetaminophen (Tylenol) and antibiotics, for pediatric patients?

Pediatric Medication Dosing Guidelines

For pediatric patients, acetaminophen should be dosed at 60 mg/kg/day divided into four doses for pain management, while antibiotics require weight-based dosing with specific adjustments based on the pathogen and infection severity. 1

Acetaminophen (Tylenol) Dosing

Standard Pediatric Dosing

• Administer 60 mg/kg/day divided into four doses (15 mg/kg per dose every 6 hours) for pain or fever management in children. 1
• The maximum daily dose should not exceed 75 mg/kg/day or 4,000 mg/day, whichever is lower. 1
• For children under 12 years, the FDA-approved extended-release formulation (650 mg caplets) is not indicated and should not be used. 2

Important Considerations

• Weight-based dosing is superior to age-based dosing for accuracy and safety. 1
• Dosing errors are common when age-based recommendations are used instead of weight-based calculations. 3
• The prescription should clearly state the child's weight, daily dose, number of divided doses, and duration of therapy. 1

Antibiotic Dosing in Pediatric Patients

Amoxicillin

• For common uncomplicated infections, administer amoxicillin 60 mg/kg/day orally divided into two doses. 1
• For pneumococcal infections with penicillin MICs ≤2.0 μg/mL, use amoxicillin 90 mg/kg/day divided into two doses or 45 mg/kg/day divided into three doses. 4

Cephalosporins

Ceftriaxone/Cefotaxime:

• Ceftriaxone: 50-100 mg/kg/day IV every 12-24 hours (maximum 4 g/day). 4
• Cefotaxime: 150-200 mg/kg/day IV divided every 6-8 hours (maximum 12 g/day). 4
• These are first-line for hospitalized children with life-threatening infections or in regions with high-level penicillin-resistant pneumococcus. 4

Cefazolin:

• 100-150 mg/kg/day IV divided every 8 hours for methicillin-susceptible Staphylococcus aureus infections. 4

Cefoxitin:

• 150-160 mg/kg/day IV divided into 3-4 doses (maximum 12 g/day) for children ≥3 months. 4, 5
• Doses >2 grams must be administered by IV infusion over 30-60 minutes diluted in normal saline or D5W. 5
• Reduce dose and extend interval in renal impairment following adult renal dosing guidelines. 5

Clindamycin

Parenteral Dosing:

• For MRSA infections: 40 mg/kg/day IV divided every 6-8 hours (or 10-13 mg/kg/dose every 6-8 hours, not exceeding 40 mg/kg/day total). 6
• For Group A Streptococcus: 40 mg/kg/day IV divided every 6-8 hours. 4, 6
• For pneumonia: 10-13 mg/kg/dose IV every 6-8 hours (maximum 40 mg/kg/day). 6

Oral Dosing:

• For MRSA infections: 30-40 mg/kg/day divided into 3-4 doses. 4, 6
• For Group A Streptococcus: 40 mg/kg/day divided into 3 doses. 4, 6
• Maximum single oral dose: 600 mg. 6

Critical Considerations:

• Only use clindamycin when local MRSA resistance rates are <10%. 6
• Do not use for suspected endocarditis or endovascular infections. 6
• Treatment duration: 7-21 days depending on infection severity and response. 6

Vancomycin

• 40-60 mg/kg/day IV divided every 6-8 hours for MRSA or resistant pneumococcal infections. 4
• Target trough levels of 10-15 mcg/mL; monitor serum concentrations and renal function closely. 4, 5

Aminoglycosides

Gentamicin:

• 3-7.5 mg/kg/day IV/IM divided every 8-24 hours depending on indication and renal function. 4
• Monitor drug levels and renal function; increased nephrotoxicity risk when combined with cephalosporins or furosemide. 5

Amikacin:

• 15-22.5 mg/kg/day IV divided every 8-24 hours. 4

Beta-Lactam/Beta-Lactamase Inhibitor Combinations

Ampicillin-Sulbactam:

• 200 mg/kg/day of ampicillin component IV divided every 6 hours. 4

Piperacillin-Tazobactam:

• 200-300 mg/kg/day of piperacillin component IV divided every 6-8 hours (maximum dose based on piperacillin component). 4

Carbapenems

Meropenem:

• 60 mg/kg/day IV divided every 8 hours. 4

Ertapenem:

• Children 3 months to 12 years: 15 mg/kg IV twice daily (maximum 1 g/day). 4
• Children ≥13 years: 1 g IV once daily. 4

Imipenem-Cilastatin:

• 60-100 mg/kg/day IV divided every 6 hours. 4

Critical Safety Principles

Weight-Based Dosing Requirements

• Always use actual body weight in kilograms for dose calculations, not age-based approximations. 1, 3
• Document the child's weight on every prescription to enable pharmacist verification. 1
• Weight estimation errors lead to dosing errors in 12.7% of cases. 7

Common Pitfalls to Avoid

• Ten-fold dosing errors occur frequently (8.6% in one study) when converting between units or diluting medications. 7
• Air entrainment during syringe preparation causes under-dosing in a significant proportion of cases. 7
• Drug dilution errors occur in 33.3% of cases when manual dilution is required. 7
• Failure to adjust doses for renal impairment significantly increases seizure and nephrotoxicity risk, particularly with cephalosporins. 5

Prescription Requirements

Every pediatric antibiotic prescription must include: 1

• Child's current weight in kilograms
• Total daily dose in mg/kg/day
• Number of divided doses per day
• Duration of therapy in days
• Specific indication for the prescription

Monitoring Parameters

• Perform routine toxicity monitoring (CBC, renal function, liver function) intermittently throughout treatment with cephalosporins, vancomycin, and aminoglycosides. 5
• Cefoxitin interferes with Jaffé method creatinine assays, producing falsely elevated values—use enzymatic creatinine assays when available. 5
• Monitor for Clostridioides difficile infection with prolonged antibiotic courses. 5

Renal Dose Adjustments

• Reduce doses and extend dosing intervals for all renally-eliminated antibiotics (cephalosporins, vancomycin, aminoglycosides) based on creatinine clearance. 5
• Standard pediatric dosing without renal adjustment significantly increases adverse event risk. 5