CurrentWashington State Health Care AuthorityPolicy 16.00.00.49-2

Rifaximin (Xifaxan®)

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This policy governs Washington Apple Health coverage and prior authorization requirements for oral rifaximin used for hepatic encephalopathy prophylaxis, IBS-D, and infectious/traveler’s diarrhea caused by noninvasive E. coli.

Policy Summary

PayerWashington State Health Care Authority

PolicyRifaximin (Xifaxan®)

Policy CodePolicy 16.00.00.49-2

Change TypeRevised

Effective DateOct 1, 2025

Next Review DateN/A

Key ActionFor non-preferred rifaximin, document inadequate response or severe-adverse-reaction intolerance or contraindication to at least two preferred agents.

SourceLink

POLICY UPDATE CHANGES

Medical-necessity criteria were updated to apply only to patients 20 years of age and younger through EPSDT.

Rifaximin became non-covered because of termination of the federal rebate agreement.

Baseline documentation of serum ammonia levels was removed from the hepatic encephalopathy criteria.

≤20 yearsEPSDT age population

12 monthsHepatic encephalopathy approval

14 daysInitial IBS-D supply

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CurrentWashington State Health Care AuthorityPolicy 16.00.00.49-2

Rifaximin (Xifaxan®)

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Policy Summary

PayerWashington State Health Care Authority

PolicyRifaximin (Xifaxan®)

Policy CodePolicy 16.00.00.49-2

Change TypeRevised

Effective DateOct 1, 2025

Next Review DateN/A

Key ActionFor non-preferred rifaximin, document inadequate response or severe-adverse-reaction intolerance or contraindication to at least two preferred agents.

SourceLink

POLICY UPDATE CHANGES

Medical-necessity criteria were updated to apply only to patients 20 years of age and younger through EPSDT.

Rifaximin became non-covered because of termination of the federal rebate agreement.

Baseline documentation of serum ammonia levels was removed from the hepatic encephalopathy criteria.

≤20 yearsEPSDT age population

12 monthsHepatic encephalopathy approval

14 daysInitial IBS-D supply

Maximum IBS-D courses

3 daysTraveler’s diarrhea duration

Non-coveredCoverage status

Coverage Criteria

EPSDT medical necessity

May be medically necessary through EPSDT when ALL of the following apply:

Covered indication
- Prophylaxis of hepatic encephalopathy
- Treatment of irritable bowel syndrome with diarrhea (IBS-D)
- Treatment of traveler’s diarrhea caused by noninvasive strains of E. coli

Hepatic encephalopathy prophylaxis—initial approval

Covered when ALL of the following are met for initial hepatic encephalopathy prophylaxis approval:

Initial hepatic encephalopathy prophylaxis

Required hepatic history
- History of overt hepatic encephalopathy
- Liver cirrhosis
Lactulose requirement
- Currently stabilized on and will continue to use lactulose at the maximally tolerated dose
- History of failure of lactulose at a maximally tolerated dose for at least 30 days
- Contraindication to lactulose
- Intolerance to lactulose

Hepatic encephalopathy prophylaxis—reauthorization

Covered when ALL of the following are met for hepatic encephalopathy reauthorization:

Hepatic encephalopathy reauthorization

Submit the most recent serum ammonia value
Clinical improvement
- Improvement in mental status
- Decrease in hospitalizations or emergency department visits
- Other predefined clinical criteria as specified by the provider

IBS-D—initial approval

Covered when ALL of the following are met for initial IBS-D approval:

Initial IBS-D therapy

ALL of the following
- Prior IBS-D therapies
  - Antidiarrheal, such as loperamide
  - Antispasmodic, such as dicyclomine
  - Tricyclic antidepressant, such as amitriptyline
Patient is at least 18 years of age

IBS-D—reauthorization

Covered when ALL of the following are met for IBS-D reauthorization:

IBS-D reauthorization

Documentation of improvement in IBS-D-related symptoms from previous course(s) of treatment
Documentation with rationale for continued use of rifaximin
Patient has not used more than two courses of treatment for IBS-D in their lifetimeLifetime courses ≤2

Infectious/traveler’s diarrhea—initial approval

Initial approval requires confirmation of the infectious etiology:

Traveler’s diarrhea

Confirm that the current episode of traveler’s diarrhea is caused by noninvasive strains of E. coli

Rifaximin (Xifaxan) is non-covered as of October 1, 2025 because the federal rebate agreement was terminated.

Dosing and Treatment Limits

Hepatic encephalopathy prophylaxis dose

IndicationProphylaxis of hepatic encephalopathy

Maximum daily dose≤1,100 mg per day

Approval period12 months when all criteria are met

IBS-D dose and duration

IndicationIrritable bowel syndrome with diarrhea (IBS-D)

Maximum dose and duration≤1,650 mg per day for 14 days

Initial supply14-day supply when all criteria are met

Prior Authorization and Documentation

Prior Authorization

Preferred-Drug Trial Required

Non-preferred agents require an inadequate response or documented intolerance due to a severe adverse reaction or contraindication to the required preferred agents before authorization can be considered.

Document inadequate response to at least two preferred agents.
If only one preferred agent exists in the class, document inadequate response to that one preferred agent.
Documented intolerance must be due to a severe adverse reaction or contraindication.

Prior Authorization

Indication-Specific Prior Authorization

Rifaximin is subject to indication-specific prior authorization criteria for hepatic encephalopathy prophylaxis, IBS-D, and infectious/traveler’s diarrhea caused by noninvasive E. coli.

Hepatic encephalopathy prophylaxis: meet the initial or reauthorization criteria.
IBS-D: meet the initial or reauthorization criteria, including course limits.

Medication Background

Rifaximin is a non-absorbable antibiotic used for gastrointestinal infections and other gastrointestinal conditions. Policy-recognized uses include bacterial gastrointestinal infections, treatment of IBS-D, and prophylaxis of hepatic encephalopathy when used with lactulose.

Definitions

EPSDT

TermEarly and Periodic Screening, Diagnostic, and Treatment (EPSDT)

DefinitionServices for patients 20 years of age and younger

Applicable populationPatients 20 years of age and younger

Noninvasive strains of E. coli

TermNoninvasive strains of E. coli

DefinitionStrains of E. coli that are not invasive

Coverage applicationTraveler’s diarrhea caused by noninvasive strains of E. coli

Initial Therapy

Hepatic encephalopathy initial therapy

Initial hepatic encephalopathy prophylaxis approval requires ALL of the following:

Hepatic encephalopathy prophylaxis

Required hepatic history
- History of overt hepatic encephalopathy
- Liver cirrhosis
Lactulose requirement
- Currently stabilized on and will continue to use lactulose at the maximally tolerated dose
- History of failure of lactulose at a maximally tolerated dose for at least 30 days

Continuation and Reauthorization

Hepatic encephalopathy continuation

Hepatic encephalopathy reauthorization requires ALL of the following:

Submit the most recent serum ammonia value
Documented improvement
- Improvement in mental status
- Decrease in hospitalizations or emergency department visits
- Other predefined clinical criteria as specified by the provider

IBS-D continuation

IBS-D reauthorization requires ALL of the following:

Preferred-Agent Requirements

Step-therapy scenario	Required prior therapy	Documentation standard
Non-preferred agent when two or more preferred agents are available	Trial of at least two preferred agents	Document inadequate response, or intolerance due to a severe adverse reaction or contraindication, to each required preferred agent
Non-preferred agent when only one preferred agent is available	Trial of the sole preferred agent	Document inadequate response to the sole preferred agent

Indication	Required prior therapies	Acceptable therapy classes	Documentation standard
IBS-D	Two prior therapies	Antidiarrheals; antispasmodics; or tricyclic antidepressants	Document failure, contraindication, or intolerance to each therapy

Quantity Limits

Rifaximin 200 mg tablet quantity limit

Drugrifaximin (Xifaxan) 200 mg tablet

Quantity limit9 tablets per course

Treatment contextInfectious/traveler’s diarrhea: 3-day treatment

Rifaximin 550 mg tablet quantity limit

Drugrifaximin (Xifaxan) 550 mg tablet

Quantity limit42 tablets per course

Treatment contextIBS-D: 14-day supply

Policy Summary

PayerWashington State Health Care Authority

PolicyRifaximin (Xifaxan®)

Policy CodePolicy 16.00.00.49-2

Change TypeRevised

Effective DateOct 1, 2025

Next Review DateN/A

Key ActionFor non-preferred rifaximin, document inadequate response or severe-adverse-reaction intolerance or contraindication to at least two preferred agents.

SourceLink

On This Page

Patient is at least 18 years of age

Dose is no more than 1,100 mg per day≤1,100 mg/day

Dose is no more than 1,650 mg per day for 14 days

≤1,650 mg/day for 14 days

Patient has not used more than two courses of treatment for IBS-D in their lifetimeLifetime courses ≤2

IBS-D lifetime treatment courses

Lifetime treatment limitNo more than 2 IBS-D treatment courses

Initial approvalThe patient must not have used more than 2 courses in their lifetime

ReauthorizationUp to 2 more 14-day supplies may be approved when criteria are met

Traveler’s diarrhea: confirm infection with a noninvasive strain of E. coli.

Step Therapy

Preferred-Agent Step Therapy

New-to-market drugs included in this class based on the Apple Health Preferred Drug List are non-preferred and require step therapy before approval.

Check the current Apple Health Preferred Drug List (AHPDL).
Apply the preferred-agent trial requirement to non-preferred agents.
AHPDL: https://www.hca.wa.gov/assets/billers-and-providers/applehealth-preferred-drug-list.xlsx

Prior Authorization

IBS-D Prior Therapy Required

For IBS-D, document failure, contraindication, or intolerance to two prior therapies before requesting rifaximin.

Eligible prior therapies include an antidiarrheal, such as loperamide.
Eligible prior therapies include an antispasmodic, such as dicyclomine.
Eligible prior therapies include a tricyclic antidepressant, such as amitriptyline.

Documentation Required

Hepatic Encephalopathy: Initial Documentation

For hepatic encephalopathy prophylaxis, submit documentation supporting the hepatic diagnosis, lactulose status, age, and requested dose.

Document a history of overt hepatic encephalopathy or liver cirrhosis.
Document that the patient is stabilized on and will continue lactulose at the maximally tolerated dose, or document failure of lactulose at the maximally tolerated dose for at least 30 days, or contraindication/intolerance to lactulose.
Patient must be 18 years or older.
Requested dose must be 1,100 mg per day or less.
When all criteria are met, initial approval is for 12 months.

Documentation Required

Hepatic Encephalopathy: Reauthorization Documentation

For hepatic encephalopathy reauthorization, submit the most recent serum ammonia laboratory value and documentation showing clinical improvement.

Document the most recent serum ammonia value(s).
Document improvement through improved mental status, decreased hospitalizations or emergency department visits, or other predefined clinical criteria specified by the provider.
When all criteria are met, reauthorization is for 12 months.

Documentation Required

IBS-D: Initial Documentation

For initial IBS-D approval, document the required prior therapy history, requested regimen, and lifetime course count.

Patient must be 18 years or older.
Document failure, contraindication, or intolerance to two prior IBS-D therapies.
Requested dose must be 1,650 mg per day or less for 14 days.
Document that the patient has not used more than two IBS-D treatment courses in their lifetime.
When all criteria are met, approval is for a 14-day supply.

Documentation Required

IBS-D: Reauthorization Documentation

For IBS-D reauthorization, document symptom improvement, the clinical rationale for continued rifaximin, and the lifetime course count.

Document improvement in IBS-D-related symptoms from prior course(s).
Provide rationale for continuing rifaximin.
Confirm that the patient has not used more than two IBS-D treatment courses in their lifetime.
When all criteria are met, approval may be for up to two additional 14-day supplies.

Documentation Required

Traveler’s Diarrhea Documentation

For infectious or traveler’s diarrhea, confirm that the episode is caused by a noninvasive strain of E. coli before requesting rifaximin.

Document confirmation of a noninvasive E. coli etiology.

Billing Rule

Rifaximin Is Non-Covered

As of October 1, 2025, rifaximin (Xifaxan) is non-covered because the federal rebate agreement was terminated.

The policy history states that medical necessity criteria apply only to patients 20 years of age and younger through Early and Periodic Screening, Diagnostic, and Treatment (EPSDT) services.

Denial Risk

Hepatic Encephalopathy Criteria Not Met

Requests for hepatic encephalopathy prophylaxis may be denied when the required clinical criteria are not met.

No documented history of overt hepatic encephalopathy or liver cirrhosis.
No qualifying lactulose stabilization, failure, contraindication, or intolerance.
Patient is younger than 18 years, or the requested dose exceeds 1,100 mg per day.
Required reauthorization serum ammonia value or documentation of clinical improvement is missing.

Denial Risk

IBS-D Limits or Prerequisites Not Met

IBS-D requests may be denied when required prior therapies, age, dosing, course limits, or reauthorization documentation are not satisfied.

Fewer than two qualifying prior IBS-D therapies were tried, or failure, contraindication, or intolerance is not documented.
Patient is younger than 18 years or the requested initial dose exceeds 1,650 mg per day for 14 days.
The patient has already used more than two IBS-D treatment courses in their lifetime.
For reauthorization, symptom improvement or rationale for continued use is not documented.

Denial Risk

Unsupported Infectious Indication

A traveler’s diarrhea request is unsupported when the infection has not been confirmed as caused by a noninvasive strain of E. coli.

Document the infectious etiology before requesting approval.
Do not rely on a traveler’s diarrhea diagnosis alone without confirmation of noninvasive E. coli infection.

Contraindication to lactulose

Intolerance to lactulose

Patient is at least 18 years of age

Dose is no more than 1,100 mg per day≤1,100 mg/day

IBS-D initial therapy

Initial IBS-D approval requires ALL of the following:

IBS-D

Failure, contraindication, or intolerance to two prior IBS-D therapies selected from antidiarrheals, antispasmodics, or tricyclic antidepressantsTwo prior therapies
Patient is at least 18 years of age
Dose is no more than 1,650 mg per day for 14 days≤1,650 mg/day for 14 days
Patient has not used more than two courses of treatment for IBS-D in their lifetimeLifetime courses ≤2

Traveler’s diarrhea initial therapy

Initial traveler’s diarrhea approval requires confirmation of the infection:

Traveler’s diarrhea

The episode must be caused by noninvasive strains of E. coli

Documentation of improvement in IBS-D-related symptoms from previous course(s) of treatment
Documentation with rationale for continued use of rifaximin
Patient has not used more than two courses of treatment for IBS-D in their lifetimeLifetime courses ≤2