What is the recommended dosing for adolescents?

Recommended Dosing Guidelines for Adolescents

For adolescents, medication dosing should follow weight-based calculations for those under 40 kg, while those weighing more than 40 kg should receive adult dosing. 1

General Dosing Principles for Adolescents

• Adolescents experience unique differences in pharmacokinetic parameters compared to adults, requiring individualized dosing approaches 2
• After age 6 months, body surface area (BSA) is generally a good marker for drug dosing, though certain medications metabolized by specific enzymes (CYP2D6, UGT) should still be dosed by weight 3
• Adolescents weighing more than 40 kg can typically receive adult dosing for most medications 1

Medication-Specific Dosing Guidelines

Stimulant Medications (ADHD Treatment)

• For methylphenidate in adolescents:

  • Initial dosing: 5-10 mg twice daily 4
  • Titration: Increase by 5-10 mg weekly until optimal response 4
  • Maximum daily doses: Up to 60 mg daily for adolescents, though some may require up to 1.0 mg/kg 4
  • Flexible dosing strategies show better outcomes than fixed dosing, allowing adjustment based on symptom control and side effects 5

• For amphetamine/dextroamphetamine in adolescents:

  • Initial dosing: 2.5-5 mg twice daily 4
  • Titration: Increase by 2.5-5 mg weekly 4
  • Maximum daily doses: Generally up to 40 mg, though some may require up to 0.9 mg/kg 4

Hormonal Medications

• For hormonal replacement therapy in adolescents:
  • A stepwise approach with gradual dose increases is recommended 6
  • Consider transdermal versus oral preparations based on individual needs 6

Contraceptives

• Combined oral contraceptives (COCs) for adolescents:
  • Standard regimens include 21-24 hormone pills and 4-7 placebo pills 4
  • Many experts recommend starting with a monophasic pill containing 30-35 μg ethinyl estradiol 4
  • Extended or continuous cycles may be beneficial for certain medical conditions (anemia, dysmenorrhea, endometriosis) 4

Vaccines

• Tdap (tetanus, diphtheria, acellular pertussis):

  • Administer at age 11-12 years 4
  • For those who missed this dose, administer a single dose of Tdap to adolescents aged 13-18 years 4

• HPV vaccine:

  • First dose at age 11-12 years 4
  • Second dose 2 months after first dose, third dose 6 months after first dose 4
  • Can be administered to previously unvaccinated females aged 13-18 years 4

• Meningococcal vaccine:

  • Administer MCV4 at age 11-12 years 4
  • For previously unvaccinated adolescents, administer at high school entry (approximately age 15) 4

Acute Medication Management

• For chemical restraint in agitated adolescents:

  • Risperidone: 0.5-1 mg for adolescents 4
  • Haloperidol: 2-5 mg for adolescents 4
  • Olanzapine: 2.5-5 mg for adolescents 4
  • Close monitoring for adverse effects is essential 4

• For influenza treatment:

  • Oseltamivir: 75 mg twice daily for 5 days for adolescents >40 kg 4
  • Weight-based dosing for those <40 kg 4
  • Treatment is most effective when started within 48 hours of symptom onset 4

Special Considerations

• Medication adherence is particularly challenging during adolescence, with compliance rates below 40% in some studies 7
• Developing a therapeutic alliance is crucial for improving medication adherence 7
• For medications with narrow therapeutic windows (like lithium), regular monitoring is essential 7
• Consider potential drug interactions with hormonal contraceptives, particularly for medications like lamotrigine 7

Common Pitfalls in Adolescent Dosing

• Treating adolescents as "small adults" without considering developmental differences in pharmacokinetics 2
• Underdosing stimulant medications, which can lead to suboptimal symptom control 5
• Failing to adjust dosing based on weight changes during periods of rapid growth 3
• Not considering the impact of hormonal changes on medication metabolism 7
• Overlooking the need for appropriate dosage forms that facilitate adherence 2