Is it safe to use Miralax (polyethylene glycol) while taking Norco (hydrocodone)?

Safety of Miralax (Polyethylene Glycol) While Taking Norco (Hydrocodone)

Miralax (polyethylene glycol) is safe and recommended for use in patients taking Norco (hydrocodone) to prevent and treat opioid-induced constipation. 1

Mechanism and Rationale

Opioid medications like hydrocodone (Norco) commonly cause constipation by:

• Slowing intestinal transit time
• Decreasing intestinal secretions
• Increasing anal sphincter tone

This makes constipation one of the most frequent and troublesome side effects of opioid therapy, affecting quality of life and potentially leading to more serious complications if left untreated.

Recommended Management Approach

First-Line Prevention (Start When Initiating Opioids)

• Polyethylene glycol (Miralax): 17g with 8 oz water once or twice daily 1
  • Highly effective and safe for opioid-induced constipation
  • Can be used safely for extended periods (up to 12 months) with no evidence of tachyphylaxis 2
  • Well-tolerated with minimal side effects compared to other laxatives 3

Alternative First-Line Options

• Stimulant laxative (e.g., senna): 2 tablets every morning (maximum 8-12 tablets per day) 1
• Combination therapy: Stimulant laxative with stool softener 1

Evidence Supporting Safety and Efficacy

Polyethylene glycol has been specifically studied for medication-induced constipation:

• A randomized controlled trial showed 78.3% treatment success with PEG compared to 39.1% with placebo in patients with constipation from medications 3
• Long-term studies demonstrate safety for up to 12 months of continuous use 2
• No significant drug interactions have been reported between polyethylene glycol and opioids 4

Important Considerations

Dosing Adjustments

• Increase laxative dose when opioid dose is increased 1
• Goal: One non-forced bowel movement every 1-2 days 1

Monitoring

• Assess for:
  • Frequency and consistency of bowel movements
  • Abdominal discomfort
  • Signs of bowel obstruction (which should be ruled out before aggressive laxative therapy) 1

Potential Side Effects of Miralax

• Generally mild and include:
  • Bloating
  • Gas
  • Mild abdominal discomfort
  • Rarely diarrhea if overdosed 5

Escalation of Therapy if Needed

If constipation persists despite Miralax:

1. Consider adding osmotic laxatives (lactulose, sorbitol) 1
2. Add stimulant laxatives if not already using (bisacodyl) 1
3. For refractory cases, consider peripherally acting μ-opioid receptor antagonists (PAMORAs) like naloxegol or methylnaltrexone 1

Common Mistakes to Avoid

• Relying solely on stool softeners without adding a stimulant or osmotic component 1
• Inadequate prophylactic dosing - be proactive rather than reactive 1
• Using bulk-forming laxatives like psyllium, which can worsen constipation if fluid intake is inadequate 1
• Delaying treatment - prevention is more effective than treating established constipation 1

Special Considerations with Norco

While taking Norco, avoid combining with benzodiazepines due to increased risk of respiratory depression and overdose 6. This is unrelated to Miralax use but important for overall safety when taking Norco.

Miralax is a safe, effective, and well-tolerated option for managing constipation in patients taking opioid medications like Norco, with strong evidence supporting its use in this specific context.