Doxycycline Dosing in Pediatric Patients
Doxycycline should be dosed at 2-4 mg/kg/day divided into 1-2 doses in children 8 years and older, with a maximum of 100-200 mg/day, while it is not recommended for children under 8 years of age due to the risk of dental staining. 1
Age Restrictions and Safety Considerations
- Doxycycline is traditionally not recommended for children younger than 8 years of age due to concerns about dental staining 1
- Recent evidence suggests short courses (<21 days) of doxycycline may be safe in children under 8 years in specific circumstances, as newer studies show minimal risk of permanent tooth discoloration compared to other tetracyclines 2
- When prescribing for children under 8 years, the benefit must clearly outweigh the risk, and this should be considered an exception rather than routine practice 1
Dosing Recommendations
Children ≥8 years:
- Oral dosing: 2-4 mg/kg/day divided into once or twice daily dosing 1
- Maximum dose: 100 mg twice daily (200 mg/day) 1
- For skin and soft tissue infections: 100 mg twice daily (in adolescents) 1
- For hidradenitis suppurativa: Recommended for patients 8 years and older 1
Children <8 years (when benefits outweigh risks):
- Limited data suggests similar weight-based dosing as older children may be appropriate 3
- Pharmacokinetic studies indicate clearance and volume of distribution in children 2-8 years are comparable to older children when allometrically scaled 3
Duration of Therapy
- Skin and soft tissue infections: 7-14 days 1, 4
- For uncomplicated skin infections: 5-10 days 4
- Short courses (<21 days) are preferred in younger children to minimize risk of dental staining 2
Administration Considerations
- Should be administered with food or fluids to minimize gastrointestinal side effects 4
- Patients should remain upright for at least 1 hour after taking doxycycline to prevent esophagitis 4
- Avoid administration with dairy products, antacids, or iron supplements as they may decrease absorption 4
Side Effects and Monitoring
- Monitor for photosensitivity reactions; advise patients to avoid direct sunlight and use sun protection 4
- Watch for gastrointestinal side effects including nausea, vomiting, and esophageal discomfort 4
- For long-term therapy, monitor for superinfection, especially with non-susceptible organisms 4
Special Considerations
- Despite historical concerns, recent pharmacokinetic data supports that doxycycline clearance in children is comparable to adults when adjusted for weight 3
- Clinicians should be aware that doxycycline may be underutilized in pediatric patients even when indicated, particularly for rickettsial diseases where it is the drug of choice regardless of age 5
- Obesity and fasting status do not significantly affect doxycycline pharmacokinetics in children, suggesting standard weight-based dosing is appropriate 3