Alternatives to Lubiprostone If You Can't Fill Your Prescription

If your pharmacy is out of Lubiprostone (Amitiza) or you're struggling to afford it, the good news is that you have options. Several effective medications treat the same conditions — chronic idiopathic constipation (CIC), irritable bowel syndrome with constipation (IBS-C), and opioid-induced constipation (OIC). This guide explains your alternatives and what to discuss with your doctor before switching.

Important: Talk to Your Doctor Before Switching

Before switching medications, always consult your prescriber. Different drugs work through different mechanisms, have different side effect profiles, and some are only approved for specific conditions or populations. Your doctor can help you find the best substitute based on your specific situation.

Alternatives for Chronic Idiopathic Constipation (CIC)

If you take Lubiprostone 24 mcg twice daily for CIC, these alternatives are worth discussing with your doctor:

Linaclotide (Linzess) — GC-C Agonist

Linaclotide (brand: Linzess) is one of the most commonly prescribed alternatives to Lubiprostone for both CIC and IBS-C. It works through a different mechanism — activating guanylate cyclase-C (GC-C) receptors — but achieves a similar result: more fluid in the intestine and easier bowel movements. For CIC, the dose is 145 mcg once daily taken on an empty stomach 30 minutes before a meal.

Key difference: Linzess is taken once daily rather than twice daily. It is also approved in pediatric patients ages 6–17 for functional constipation. The most common side effect is diarrhea, which can be severe. Linzess does not yet have a generic available (expected around 2029).

Plecanatide (Trulance) — GC-C Agonist

Plecanatide (brand: Trulance) is another GC-C agonist approved for both CIC and IBS-C in adults. It is taken as one 3 mg tablet once daily and can be taken with or without food. Unlike Linzess, it is pH-independent, which can make it a better option for patients taking proton pump inhibitors (PPIs).

Key difference: Trulance has a better tolerability profile in some studies — fewer reports of severe diarrhea compared to Linzess. No generic available. Can be taken with or without food, unlike Linzess (which requires an empty stomach).

Prucalopride (Motegrity) — 5-HT4 Receptor Agonist

Prucalopride (brand: Motegrity) works through an entirely different mechanism — it selectively activates serotonin 5-HT4 receptors in the gut, which speeds up colon motility. It is approved for CIC in adults and taken as one 2 mg tablet once daily.

Key difference: Motegrity is particularly useful when secretagogues like Lubiprostone or GC-C agonists like Linzess haven't worked. It promotes movement throughout the colon rather than just increasing fluid secretion. Can be taken with or without food.

Alternatives for IBS-C (Women ≥18 Years)

Lubiprostone's IBS-C indication is only approved for adult women. If you take Lubiprostone 8 mcg twice daily for IBS-C, note that some experts prefer GC-C agonists (linaclotide, plecanatide) for IBS-C because they address both constipation AND abdominal pain — while Lubiprostone primarily addresses the constipation component but may not relieve IBS-related pain as effectively.

Tenapanor (Ibsrela) is another option for IBS-C specifically. It works by inhibiting a sodium transport protein in the gut, reducing fluid absorption and increasing intestinal fluid. It's taken twice daily with meals.

Alternatives for Opioid-Induced Constipation (OIC)

If you take Lubiprostone for OIC (constipation caused by opioid pain medications), the alternatives are different because OIC has a specific mechanism — opioids block mu-receptors in the gut, slowing motility. The best alternatives for OIC are peripherally acting mu-opioid receptor antagonists (PAMORAs):

• Naloxegol (Movantik): Oral tablet, once daily. Blocks opioid receptors in the gut without reversing the pain-relieving effects of opioids in the brain.
• Naldemedine (Symproic): Oral tablet, once daily. Similar mechanism to Movantik.
• Methylnaltrexone (Relistor): Available as subcutaneous injection or oral tablet. Older PAMORA; useful when oral options aren't working.

Over-the-Counter Options

For milder constipation, several OTC options may bridge the gap temporarily while you work on finding your Lubiprostone:

• Polyethylene glycol (MiraLAX): Osmotic laxative; available OTC; effective for general constipation.
• Docusate sodium (Colace): Stool softener; gentle; often combined with other laxatives.
• Fiber supplements (Metamucil, Citrucel): Bulk-forming agents; can help with regular constipation; ensure adequate water intake.

The Bottom Line

Lubiprostone works well for many patients, and the goal should always be to find your medication first. If you haven't already, read our guide on why Lubiprostone is hard to find and use medfinder to locate it near you. But if you truly can't access it, the alternatives above — particularly Linzess, Trulance, or Motegrity for CIC/IBS-C, and PAMORAs for OIC — are evidence-based, effective options your doctor can help you navigate.