Understanding Suboxone and Opioid-Induced Constipation (OIC)
Suboxone is a medication containing buprenorphine and naloxone, commonly used for medication-assisted treatment (MAT) for opioid use disorder [1.2.3]. While effective, a frequent side effect is opioid-induced constipation (OIC). The buprenorphine in Suboxone, like other opioids, binds to mu-opioid receptors in the gastrointestinal tract [1.4.2]. This action slows down gut motility (the movement of the intestines), increases fluid absorption from the stool, and tightens the anal sphincter, all of which lead to hard, dry stools that are difficult to pass [1.4.1, 1.4.2]. The prevalence of constipation in Suboxone users can be as high as 81% [1.4.2].
Symptoms of OIC
Symptoms of OIC go beyond just infrequent bowel movements. They can include [1.4.1]:
- Fewer than three bowel movements a week
- Hard, dry, or lumpy stools
- Straining or pain during bowel movements
- A feeling of incomplete evacuation
- Abdominal pain, bloating, and nausea
First-Line Relief: Lifestyle and Dietary Adjustments
Before turning to medication, experts recommend making several lifestyle and dietary changes. These strategies are foundational for managing OIC and improving overall gut health [1.2.1, 1.5.1].
Increase Fluid and Fiber Intake
- Hydration: Drink at least eight glasses of water per day, or about 1.5-2 liters [1.2.3, 1.5.1]. Adequate water intake helps soften stool, making it easier to pass, especially when increasing fiber [1.2.4].
- Dietary Fiber: Aim for 25 to 38 grams of fiber daily [1.2.3, 1.5.3]. Excellent sources include fruits (apples, prunes, berries), vegetables (broccoli, spinach), whole grains, and legumes (beans, lentils) [1.2.5, 1.5.2]. However, one source warns that bulk-forming fiber supplements (like psyllium or Metamucil) should be avoided, as they can worsen abdominal pain if gut motility is severely slowed by the opioid [1.2.5].
Regular Physical Activity
- Get Moving: Regular exercise, even daily walking, helps stimulate the natural contractions of your intestinal muscles, promoting more regular bowel movements [1.2.2, 1.5.5].
Other Helpful Habits
- Toilet Routine: Try to establish a regular time each day for a bowel movement and don't ignore the urge to go [1.5.5]. Some find that raising their feet with a stool while on the toilet can make having a bowel movement easier [1.4.1].
- Spit, Don't Swallow: After Suboxone has dissolved under the tongue, some patients report that spitting out the remaining saliva instead of swallowing it may reduce constipation [1.2.2]. This is because buprenorphine is not well-absorbed when swallowed but can still affect the opioid receptors in the gut [1.2.2].
Over-the-Counter (OTC) Medications
When lifestyle changes aren't enough, several OTC options can provide relief. It's always best to consult with your doctor or pharmacist before starting any new medication [1.2.2].
Types of Laxatives
- Osmotic Laxatives: These are often recommended as a first-line therapy [1.7.5]. They work by drawing more water into the intestines to soften stool [1.3.3, 1.7.4]. Polyethylene glycol (MiraLAX) is a commonly used and effective option [1.2.5]. Milk of Magnesia is another type of osmotic laxative [1.3.1].
- Stool Softeners: Products like docusate sodium (Colace) work by helping water and fats mix into the stool, making it softer [1.2.1, 1.3.4]. Stool softeners are often seen as better for preventing constipation rather than treating an existing case [1.7.1].
- Stimulant Laxatives: Medications like senna (Senokot) or bisacodyl (Dulcolax) work by stimulating the muscles in the bowels to contract and move stool along [1.3.4]. They are effective for OIC and are often used in combination with a stool softener [1.2.5, 1.7.1]. However, they are not typically recommended for long-term use [1.3.3].
| Laxative Type | How It Works | Common Examples | Onset of Action | Best For |
|---|---|---|---|---|
| Osmotic | Draws water into the colon to soften stool [1.7.4]. | Polyethylene glycol (MiraLAX), Milk of Magnesia [1.2.5]. | 24-48 hours (PEG), 30 min-6 hours (Magnesium) [1.7.3]. | Gentle, regular relief [1.7.5]. |
| Stool Softener | Allows more water and fat to be absorbed by the stool [1.3.1]. | Docusate sodium (Colace) [1.3.1]. | 24-48 hours [1.7.3]. | Prevention, mild constipation [1.7.1]. |
| Stimulant | Triggers intestinal muscle contractions to move stool [1.3.4]. | Senna (Senokot), Bisacodyl (Dulcolax) [1.2.5]. | 6-12 hours [1.7.3]. | More immediate relief, often combined with a stool softener [1.7.1]. |
Prescription Medications for OIC
If OTC treatments are ineffective, a doctor may prescribe a medication specifically designed to treat OIC [1.2.4].
Peripherally Acting Mu-Opioid Receptor Antagonists (PAMORAs)
PAMORAs are a class of drugs that block opioid receptors in the gut without crossing the blood-brain barrier, so they don't interfere with Suboxone's primary effect [1.6.1, 1.8.2].
- Naloxegol (Movantik): A once-daily oral tablet taken on an empty stomach to treat OIC in adults with chronic non-cancer pain [1.8.3, 1.8.4].
- Methylnaltrexone (Relistor): Available as both an oral tablet and a subcutaneous injection for adults with chronic non-cancer pain [1.6.1, 1.9.4].
- Naldemedine (Symproic): A once-daily oral tablet that can be taken with or without food [1.6.1].
Other Prescription Options
- Lubiprostone (Amitiza): This medication works differently by activating chloride channels in the intestines, which increases fluid secretion and softens stool [1.10.1, 1.10.3]. It's approved for OIC and taken twice daily with food and water [1.10.2].
Conclusion
Constipation from Suboxone is a manageable side effect. The first step is to implement consistent lifestyle and dietary changes, including increased hydration, fiber, and exercise [1.2.1]. If these measures are insufficient, OTC osmotic laxatives like MiraLAX or a combination of a stool softener and a stimulant laxative are effective next steps [1.2.5, 1.7.1]. For persistent cases, speak with a healthcare provider about prescription medications like Movantik, Relistor, or Amitiza that are specifically designed to counteract OIC without affecting your primary treatment [1.6.1]. Always consult your doctor before starting or changing your approach to managing constipation.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before making any decisions about your health or treatment.
For more information on Opioid-Induced Constipation, you can visit the National Institute of Diabetes and Digestive and Kidney Diseases.
