What is the recommended dosage of Laxaday (Senna) for a patient with constipation, considering their age, medical history, and current medications?

Prescription Laxaday (Polyethylene Glycol) Dosage

Note: Laxaday is polyethylene glycol (PEG), not senna—these are different medications with distinct mechanisms of action, and the recommended dosing differs significantly.

Recommended Initial Dosing

Start Laxaday (PEG 3350) at 17 g (approximately one capful or sachet) dissolved in 240 mL (8 oz) of water once daily. 1

• PEG is an osmotic laxative that traps water in the intestine to soften stool and increase bowel movements 1
• The 17 g daily dose is the evidence-based starting point recommended by the American Gastroenterological Association and American College of Gastroenterology for chronic idiopathic constipation 1
• This medication costs $10-45 per month, making it highly cost-effective 1

Dose Titration Strategy

Titrate the dose upward based on symptom response and tolerability, with no clear maximum dose. 1

• Adjust daily during the first week based on clinical response 2
• The goal is one non-forced bowel movement every 1-2 days 1, 2
• If 17 g daily is insufficient after several days, increase to 34 g daily (two capfuls) 3
• PEG response has been shown to be durable over 6 months of continuous use 1

For Acute Constipation or Rapid Relief

For overnight relief in acute constipation, consider a higher single dose of 68 g dissolved in 500 mL of flavored water. 3

• This dose provides safe and effective relief within 24 hours, with median time to first bowel movement of 14.8 hours 3
• 100% of patients achieved complete evacuation with the second bowel movement at this dose 3
• No adverse reactions, incontinence, cramping, or electrolyte disturbances occurred at this dose 3

Important Clinical Considerations

Ensure adequate hydration as PEG works by drawing water into the intestine. 1

• Common side effects include bloating, abdominal discomfort, and cramping, which are typically mild 1
• PEG can be used long-term with established safety data extending beyond 6 months 1
• No electrolyte monitoring is required in patients with normal renal function 3

If PEG Alone Is Insufficient

Add a stimulant laxative such as senna 8.6-17.2 mg daily (1-2 tablets) at bedtime if PEG monotherapy fails. 1, 4

• Senna can be titrated up to a maximum of 4 tablets twice daily based on response 1, 4
• For opioid-induced constipation specifically, combine senna with docusate (stool softener) as prophylaxis 1
• Consider prescription agents (lubiprostone, linaclotide, prucalopride) if requiring frequent rescue therapy despite optimized over-the-counter regimen 2