What is the recommended dosage of senna (ex-lax) tablets for pediatric patients?

Senna Tablet Dosing for Pediatric Patients

For children 2-6 years old, give 1/2 to 3/4 teaspoon (2.5 to 3.75 mL) of senna liquid once daily at bedtime, with a maximum of 3/4 teaspoon (3.75 mL) once daily; for children 6-12 years old, give 1 to 1 1/2 teaspoons (5 to 7.5 mL) once daily, with a maximum of 1 1/2 teaspoons (7.5 mL) twice daily; and for children 12 years and older, give 2-3 teaspoons (10 to 15 mL) once daily, with a maximum of 3 teaspoons (15 mL) twice daily. 1

Age-Specific Dosing Guidelines

Children Under 2 Years

• Senna should not be used without consulting a physician 1
• This age group requires individualized medical supervision before initiating senna therapy 1

Children 2-6 Years Old

• Starting dose: 1/2 to 3/4 teaspoon (2.5 to 3.75 mL) once daily at bedtime 1
• Maximum dose: 3/4 teaspoon (3.75 mL) once daily 1
• Administer at bedtime or as directed by a physician 1

Children 6-12 Years Old

• Starting dose: 1 to 1 1/2 teaspoons (5 to 7.5 mL) once daily at bedtime 1
• Maximum dose: 1 1/2 teaspoons (7.5 mL) twice daily 1
• The liquid formulation should be shaken well before use 1

Children 12 Years and Older

• Starting dose: 2-3 teaspoons (10 to 15 mL) once daily at bedtime 1
• Maximum dose: 3 teaspoons (15 mL) twice daily 1
• This dosing is equivalent to adult dosing 1

Clinical Effectiveness and Safety

Efficacy in Pediatric Populations

• Senna has demonstrated superior effectiveness compared to polyethylene glycol in children with anorectal malformations and constipation, with statistically significant benefit (p = 0.026) 2
• The stimulant action of senna produces colonic contractions that improve motility without affecting stool consistency, which is particularly beneficial for maintaining fecal continence 2
• In a study of 640 pediatric patients treated with senna from 2014-2017, the medication was well-tolerated with only minor side effects in 13% of patients 3

Important Safety Considerations

Critical Warning About Perineal Blistering:

• Severe diaper rash with blistering can occur in 2.2% of children taking senna, particularly at higher doses (mean 60 mg/day vs. 17.5 mg/day in those without blistering, p<0.001) 3
• Blistering episodes are associated with nighttime accidents and prolonged stool-to-skin contact (mean onset 14.5 ± 6.8 hours) 3
• Children wearing diapers have significantly higher risk of severe diaper rash and skin breakdown compared to toilet-trained children (p < 0.05) 4
• Prevention strategy: Change diapers frequently, cleanse the perianal area promptly after bowel movements, and apply barrier ointment liberally 3, 4

Common Side Effects

• Minor side effects including abdominal cramping, vomiting, or diarrhea occur in approximately 13% of patients during initial weeks of treatment 3
• These symptoms typically resolve with dose adjustment or change in laxative type 3
• No evidence of tolerance development to senna has been documented in pediatric literature 3

Clinical Pitfalls to Avoid

• Do not exceed maximum recommended doses as higher doses (>60 mg/day) are associated with increased risk of perineal blistering 3
• Avoid overnight dosing in non-toilet-trained children when possible, as nighttime accidents with prolonged stool exposure increase blistering risk 3, 4
• Monitor children in diapers closely for early signs of skin irritation, as they are at significantly higher risk for severe complications 4
• Educate parents immediately about the risk of severe diaper rash and the importance of frequent diaper changes and barrier protection 3, 4