Maximum Dosage of Doxycycline for Children Weighing Over 100 Pounds
For children weighing over 100 pounds (>45 kg), the maximum recommended daily dose of doxycycline is 200 mg on the first day (administered as 100 mg every 12 hours), followed by a maintenance dose of 100 mg per day. 1, 2
Dosing Guidelines Based on Weight
- For children weighing over 100 pounds (>45 kg), the adult dosage should be used: 200 mg on the first day (100 mg every 12 hours), followed by 100 mg daily maintenance dose 2, 1
- For children weighing 100 pounds or less: 2 mg/lb (4.4 mg/kg) of body weight divided into two doses on the first day, followed by 1 mg/lb (2.2 mg/kg) given as a single daily dose or divided into two doses on subsequent days 1, 3
- For more severe infections, up to 2 mg/lb (4.4 mg/kg) of body weight may be used daily even after the first day 1
Age Considerations
- Doxycycline is generally not recommended for children under 8 years of age due to potential for dental staining and bone growth effects, unless benefits outweigh risks 4, 2
- For children 8 years and older, doxycycline can be safely administered at the weight-based dosages described above 3, 1
- The American Academy of Pediatrics has amended recommendations to allow treatment of young children with doxycycline for serious infections when benefits outweigh risks 2
Condition-Specific Dosing
- For severe acne: The maximum daily dose remains 100 mg/day for maintenance therapy in children >100 pounds 2
- For anthrax post-exposure prophylaxis: 100 mg twice daily for 60 days for children weighing 100 pounds or more 1, 2
- For malaria prophylaxis: 100 mg daily for children over 8 years of age weighing more than 45 kg 1
- For tickborne rickettsial diseases: 100 mg twice daily for at least 3 days after fever subsides (minimum 5-7 days total) 3
Administration Recommendations
- Doxycycline should be administered with adequate amounts of fluid to reduce the risk of esophageal irritation and ulceration 1, 3
- If gastric irritation occurs, doxycycline can be given with food or milk, although this may slightly reduce absorption 1
- For improved compliance, the daily maintenance dose can be given as a single dose or divided into two doses 1
Safety Considerations
- Common adverse effects include gastrointestinal symptoms (nausea, vomiting, diarrhea), photosensitivity, and rash 3, 2
- Avoid co-administration with antacids containing aluminum, calcium, or magnesium (should be taken at least 2-3 hours before or after doxycycline) 3
- Pharmacokinetic studies have shown that appropriately dosed doxycycline achieves similar serum levels in children as in adults 5
Remember that exceeding the recommended dosage may result in an increased incidence of side effects 1. The therapeutic antibacterial serum activity typically persists for 24 hours following the recommended dosage 1.