When You Can't Get Rifaximin, What Are Your Options?

If you've been prescribed Rifaximin (brand name Xifaxan) and can't find it at your pharmacy — or simply can't afford the $1,800 to $2,400 cash price — you're not out of options. While Rifaximin is an excellent medication for several GI conditions, there are alternatives that your doctor can prescribe depending on your specific diagnosis.

In this guide, we'll cover what Rifaximin is, how it works, and the most common alternatives for each condition it treats. Important: Never switch medications on your own. Always talk to your doctor before making any changes to your treatment plan.

For help locating Rifaximin itself, see our guide: How to Find Rifaximin in Stock Near You.

What Is Rifaximin and How Does It Work?

Rifaximin is a non-absorbable antibiotic in the rifamycin class. It works by binding to bacterial RNA polymerase, which stops bacteria from multiplying. Because less than 0.4% of Rifaximin is absorbed into the bloodstream, it acts almost entirely inside the gut. This local action makes it effective with very few systemic side effects.

The FDA has approved Rifaximin for:

• Traveler's diarrhea caused by E. coli
• Hepatic encephalopathy (HE) — reducing the risk of recurrence in adults with liver disease
• Irritable bowel syndrome with diarrhea (IBS-D)

Doctors also commonly prescribe it off-label for small intestinal bacterial overgrowth (SIBO). For a deeper dive, read: How Does Rifaximin Work?

Alternatives for Hepatic Encephalopathy

If you take Rifaximin to prevent hepatic encephalopathy episodes, these are the most commonly used alternatives:

Lactulose

Lactulose is an osmotic laxative and the first-line treatment for hepatic encephalopathy. In fact, many insurance plans require patients to try Lactulose before they'll cover Rifaximin. Lactulose works by drawing water into the bowel and promoting the excretion of ammonia — the toxin that causes encephalopathy symptoms.

• How it's taken: Oral solution, typically 15-30 mL two to four times daily, adjusted to produce 2-3 soft stools per day
• Pros: Inexpensive (often under $30/month), widely available, long track record
• Cons: Can cause bloating, gas, cramping, and diarrhea; taste can be unpleasant; requires dose adjustments

Many patients actually take Lactulose and Rifaximin together for best results. If you're only on Rifaximin, your doctor may add or switch to Lactulose.

Neomycin

Neomycin is an aminoglycoside antibiotic that, like Rifaximin, works in the gut to reduce ammonia-producing bacteria. It has been used for hepatic encephalopathy for decades.

• How it's taken: Oral tablets, typically 500 mg to 1,000 mg every 6 to 8 hours
• Pros: Affordable generic option, effective at reducing ammonia levels
• Cons: Risk of kidney toxicity and hearing damage with long-term use; not ideal for ongoing therapy; requires monitoring

Neomycin is generally used as a short-term option rather than a long-term replacement for Rifaximin.

Alternatives for IBS-D

If you take Rifaximin for irritable bowel syndrome with diarrhea, these options may help:

Alosetron (Lotronex)

Alosetron is a 5-HT3 receptor antagonist approved for severe IBS-D in women who have not responded to other treatments. It slows gut motility and reduces pain signaling.

• How it's taken: 0.5 mg to 1 mg orally, twice daily
• Pros: Can significantly reduce diarrhea and abdominal pain in appropriate patients
• Cons: Only approved for women with severe IBS-D; restricted prescribing program due to risk of ischemic colitis and severe constipation; requires enrollment in the Lotronex Prescribing Program

Eluxadoline (Viberzi)

Eluxadoline is a mixed opioid receptor agonist/antagonist approved for IBS-D in adults. It reduces bowel contractions and fluid secretion.

• How it's taken: 75 mg or 100 mg orally, twice daily with food
• Pros: Approved for both men and women; can improve stool consistency and reduce abdominal pain
• Cons: Cannot be used in patients without a gallbladder or with a history of pancreatitis; classified as a Schedule IV controlled substance; may cause constipation, nausea, or abdominal pain

Alternatives for SIBO

If your doctor prescribed Rifaximin off-label for small intestinal bacterial overgrowth, common alternatives include:

Metronidazole (Flagyl)

Metronidazole is a commonly used antibiotic for various GI infections, including SIBO. It's much less expensive than Rifaximin.

• How it's taken: 250 mg to 500 mg orally, three times daily for 7 to 14 days
• Pros: Widely available, inexpensive generic (often under $15), effective against anaerobic bacteria
• Cons: More systemic side effects than Rifaximin (nausea, metallic taste, neuropathy with prolonged use); cannot be combined with alcohol

Ciprofloxacin

Ciprofloxacin is a fluoroquinolone antibiotic sometimes used for SIBO, particularly when other options haven't worked.

• How it's taken: 250 mg to 500 mg orally, twice daily for 7 to 14 days
• Pros: Effective broad-spectrum antibiotic, affordable generic
• Cons: FDA black box warning for risk of tendon rupture, nerve damage, and other serious side effects; generally reserved for cases where safer options have failed

How to Decide Which Alternative Is Right for You

The best alternative depends on:

• Your diagnosis — Hepatic encephalopathy, IBS-D, and SIBO each have different treatment approaches
• Your medical history — Some alternatives have restrictions (e.g., Alosetron is only for women; Eluxadoline can't be used without a gallbladder)
• Cost considerations — Lactulose and Metronidazole are far less expensive than Rifaximin
• Duration of treatment — Some alternatives are better for short-term use while you wait for Rifaximin to become available

Always discuss options with your doctor or gastroenterologist. They can help you weigh the benefits and risks based on your specific situation.

Don't Give Up on Finding Rifaximin

Before switching to an alternative, it's worth trying to locate Rifaximin. Use Medfinder to check real-time availability at pharmacies near you. You may also qualify for savings programs that can bring the cost down significantly — see our guide: How to Save Money on Rifaximin in 2026.

Final Thoughts

Rifaximin is a uniquely effective medication, but it's not the only option. If you can't find it or can't afford it, alternatives like Lactulose, Neomycin, Metronidazole, Alosetron, and Eluxadoline may be able to fill the gap — temporarily or long-term. The key is working closely with your healthcare provider to find the right fit for your condition and circumstances.

For the latest on Rifaximin availability, check out our 2026 shortage update.