Prescribing MiraLAX (Polyethylene Glycol 3350) for Home Use
Prescribe polyethylene glycol 3350 (MiraLAX) as 17 g packets, with instructions to take one packet (17 g) dissolved in 8 oz of water once or twice daily, and send the patient home with a standard box containing 14-30 packets. 1
Standard Dosing and Packaging
Initial dose: Start with 17 g (one packet or one capful) dissolved in 8 oz of water once daily 2, 1
Titration: Adjust dose based on symptom response and side effects, with no clear maximum dose 2
Common dosing range:
- Most patients respond to 17 g daily 2, 3
- Some patients may require 17 g twice daily (34 g total) for optimal effect 2
- Higher doses (51-68 g) can be used for acute constipation relief within 24 hours, though this is not standard maintenance dosing 4
Prescription Instructions
Write the prescription as:
- Medication: Polyethylene glycol 3350 (MiraLAX) 17 g packets
- Quantity: 14-30 packets (for 2-4 weeks supply at once daily dosing)
- Directions: "Dissolve one packet (17 g) in 8 oz of any beverage once daily. May increase to twice daily if needed for symptom control."
- Refills: As appropriate for chronic management 2
Key Clinical Points
Efficacy timeline: Greatest efficacy typically occurs in week 2 of treatment, with durable response demonstrated over 6-12 months of continuous use 2, 3, 5
Patient counseling:
- Can be mixed with any beverage of choice for better palatability 1, 3
- Common side effects include bloating, abdominal discomfort, cramping, and flatulence 2
- Ensure adequate fluid intake throughout the day 2
- Goal is one non-forced bowel movement every 1-2 days 2
Safety profile: Long-term use (up to 12 months) shows no clinically significant changes in electrolytes, no evidence of tachyphylaxis, and minimal adverse effects beyond gastrointestinal complaints 5
Cost consideration: Monthly cost ranges from $10-45, making it one of the most affordable laxative options 2
Practical Prescribing Approach
For prophylaxis in opioid-induced constipation: Prescribe 17 g twice daily from the start of opioid therapy, as patients do not develop tolerance to opioid-induced constipation 2
For chronic idiopathic constipation: Start with 17 g once daily and titrate upward to twice daily if inadequate response after 1-2 weeks 2
For acute constipation relief: Consider 68 g as a single dose for relief within 24 hours, though this is off-label for acute use 4
Standard box sizes typically contain 14 or 30 packets, providing 2-4 weeks of therapy at once-daily dosing 1