Dosage Calculation for Co-amoxiclav 312.5mg/5ml for a 13kg Patient
For a 13kg child requiring co-amoxiclav at 50mg/kg/day, the correct dose is 3.25ml twice daily or 2.17ml three times daily of the 312.5mg/5ml suspension. 1
Dosage Calculation Process
- The recommended dose of 50mg/kg/day refers to the amoxicillin component of co-amoxiclav 1
- For a 13kg child: 13kg × 50mg/kg/day = 650mg of amoxicillin per day 1
- The 312.5mg/5ml suspension contains 250mg amoxicillin and 62.5mg clavulanic acid per 5ml 1
- To calculate the daily volume needed: (650mg ÷ 250mg) × 5ml = 13ml per day 1
Dosing Frequency Options
- Twice daily dosing: 13ml ÷ 2 = 6.5ml per dose (can be rounded to 6.5ml) 1, 2
- Three times daily dosing: 13ml ÷ 3 = 4.33ml per dose (can be rounded to 4.3ml) 1, 3
- For practical purposes and better compliance, twice daily dosing is often preferred 2, 4
Dosing Considerations Based on Infection Severity
- For mild infections, a standard dose of 45mg/kg/day (approximately 585mg/day for a 13kg child) divided into 2-3 doses is appropriate 1, 5
- For moderate to severe infections, a higher dose of 90mg/kg/day (approximately 1170mg/day for a 13kg child) divided into 2-3 doses may be required 5, 1
- The 50mg/kg/day dose requested falls between standard and high-dose regimens, making it appropriate for mild to moderate infections 1
Administration Guidelines
- Co-amoxiclav suspension should be shaken well before each use 1, 3
- The medication should be administered at the start of a meal to minimize gastrointestinal intolerance 3
- Any unused portion must be discarded after 14 days 3
- Refrigeration is preferable but not required 3
Potential Pitfalls and Considerations
- Underdosing may lead to treatment failure and promote antibiotic resistance 1, 6
- Incorrect dosing frequency may result in inadequate drug levels 1, 7
- For children with renal impairment, dose adjustment may be necessary 3
- If no clinical improvement is observed after 72 hours, reevaluation of diagnosis or consideration of alternative antibiotics may be necessary 1
Duration of Treatment
- Treatment should be continued for a minimum of 48 to 72 hours beyond the time that the patient becomes asymptomatic 3
- For most common infections, a 7-day course is typically recommended 1
- For certain infections like streptococcal infections, at least 10 days of treatment is recommended to prevent complications 3