What is the appropriate dosing of penicillin (antibiotic) in liquid form for a child with streptococcal (strep) pharyngitis, weighing 56 kilograms, using a formulation of 125mg or 250mg?

From the Guidelines

For a child weighing 56 kg with strep pharyngitis, I recommend oral penicillin V potassium liquid at a dose of 500 mg (20 mL of the 250 mg/5 mL formulation) taken twice daily for 10 days, as this is the most effective regimen according to the latest guidelines 1. Since the patient weighs 56 kg, which is essentially adult weight, the adult dosing regimen is appropriate. The liquid formulation is available as either 125 mg/5 mL or 250 mg/5 mL, and I recommend using the 250 mg/5 mL concentration for easier administration of the required dose. The total daily dose should be 1000 mg divided into two doses. Penicillin works by inhibiting bacterial cell wall synthesis, which is effective against Group A Streptococcus, the causative agent of strep pharyngitis. The full 10-day course must be completed even if symptoms improve earlier to ensure complete eradication of the bacteria and prevent complications such as rheumatic fever or post-streptococcal glomerulonephritis, as emphasized in the guidelines 1. Some key points to consider when treating strep pharyngitis include:

• Accurate diagnosis of strep pharyngitis is crucial to prevent unnecessary antibiotic use and potential resistance 1
• The medication should be taken on an empty stomach, 1 hour before or 2 hours after meals, for optimal absorption
• The patient should be monitored for potential side effects and complications, and the treatment regimen should be adjusted as needed
• It is essential to complete the full 10-day course of antibiotics to ensure complete eradication of the bacteria and prevent potential complications, as recommended by the IDSA guidelines 1

From the FDA Drug Label

The usual dosage recommendations for adults and children 12 years and over are as follows: Streptococcal infections - mild to moderately severe - of the upper respiratory tract and including scarlet fever and erysipelas: 125 mg to 250 mg (200,000 to 400,000 units) every 6 to 8 hours for 10 days Each teaspoon (5 mL) will contain Penicillin V Potassium equivalent to 125 mg or 250 mg of Penicillin V

The patient weighs 56 kilos, which is approximately 123 lbs, so they are over 60 lbs.

• The recommended dosage for a child with strep pharyngitis is 125 mg to 250 mg every 6 to 8 hours for 10 days.
• The available formulation is 125 mg/5 mL or 250 mg/5 mL.
• Since the patient is a child, the 250 mg/5 mL formulation can be used, but the dose should be adjusted according to the patient's weight and the severity of the infection.
• The dose for this patient would be 250 mg every 6 to 8 hours for 10 days, which is equivalent to 2 teaspoons (10 mL) of the 125 mg/5 mL formulation or 1 teaspoon (5 mL) of the 250 mg/5 mL formulation 2.

From the Research

Penicillin Dosing for Child with Streptococcal Pharyngitis

• The patient weighs 56 kilos and the formulation is either 125mg or 200mg of penicillin in liquid form.
• According to the studies, penicillin is the drug of choice for streptococcal pharyngitis 3.
• The recommended course of penicillin is 10 days 4, 5, 6.
• The dosage of penicillin is not explicitly stated in the provided studies, but it is mentioned that amoxicillin is equally effective and more palatable than penicillin 5.
• A study comparing azithromycin and penicillin V for treatment of acute group A streptococcal pharyngitis in children used a dosage of 100,000 IU/kg/day penicillin V oral suspension in three divided doses 7.
• However, the exact dosage of penicillin in liquid form for a child weighing 56 kilos is not provided in the studies.

Formulation of Penicillin

• The formulation of penicillin is either 125mg or 200mg in liquid form.
• The studies do not provide information on the specific formulation of penicillin to use for a child weighing 56 kilos.
• It is recommended to consult a healthcare professional to determine the appropriate dosage and formulation of penicillin for the patient.

Treatment of Streptococcal Pharyngitis

• The treatment of streptococcal pharyngitis includes a 10-day course of penicillin or amoxicillin 4, 5, 6.
• Patients allergic to penicillin can be treated with first-generation cephalosporins, clindamycin, or macrolide antibiotics 4, 6.
• Nonsteroidal anti-inflammatory drugs are more effective than acetaminophen and placebo for treatment of fever and pain associated with streptococcal pharyngitis 6.