Xifaxan 550mg Tablets
It is used to prevent brain problems caused by very bad liver disease.It is used to treat travelers' diarrhea.It is used to treat irritable bowel syndrome with diarrhea (IBS-D).It may be given to you for other reasons. Talk with the doctor.
Drug Class
Gastrointestinal Agent, Antibiotic
Pharmacologic Class
Rifamycin derivative, Non-systemic antibiotic
Pregnancy Category
Category C
FDA Approved
Mar 2010
DEA Schedule
Not Controlled
Overview
What is this medicine?
Xifaxan is an antibiotic that works mainly in your intestines, not throughout your body. It's used to help prevent a brain condition called hepatic encephalopathy in people with liver disease, or to treat irritable bowel syndrome with diarrhea (IBS-D). It works by reducing certain bacteria in your gut.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Continue taking the medication as directed by your doctor or healthcare provider, even if you start feeling well. You can take this medication with or without food.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs available in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Continue taking the medication as directed by your doctor or healthcare provider, even if you start feeling well. You can take this medication with or without food.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so. If you have questions about disposing of your medication, consult your pharmacist. You may also want to check if there are drug take-back programs available in your area.
Missing a Dose
If you miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- For hepatic encephalopathy, continue to follow your doctor's dietary recommendations (e.g., low protein diet) and other treatments (e.g., lactulose).
- For IBS-D, continue to follow any dietary or lifestyle recommendations from your doctor.
- Take the medication exactly as prescribed, with or without food.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Hepatic Encephalopathy: 550 mg orally twice daily; Irritable Bowel Syndrome with Diarrhea (IBS-D): 550 mg orally three times daily for 14 days
Dose Range:
550 - 1650 mg
Condition-Specific Dosing:
hepaticEncephalopathy:
550 mg orally twice daily
ibsD:
550 mg orally three times daily for 14 days
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Not established
Adolescent:
Hepatic Encephalopathy: 550 mg orally twice daily (for patients âĨ16 years of age); IBS-D: Not established
Dose Adjustments
Renal Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed
Dialysis:
No specific recommendations; minimal systemic absorption
Hepatic Impairment:
Mild:
No adjustment needed
Moderate:
No adjustment needed
Severe:
No adjustment needed; systemic exposure is low even in severe hepatic impairment, but caution is advised
Pharmacology
Mechanism of Action
Rifaximin is a non-systemic antibiotic that acts locally in the gastrointestinal tract. It inhibits bacterial RNA synthesis by binding to the beta-subunit of bacterial DNA-dependent RNA polymerase. This action reduces the production of ammonia-producing bacteria in the gut, which is beneficial in hepatic encephalopathy, and alters the gut microbiome in IBS-D.
Pharmacokinetics
Absorption:
Bioavailability:
<0.4% (systemic)
Tmax:
~1 hour (systemic, but very low concentrations)
FoodEffect:
Minimal impact on systemic absorption; can be taken with or without food
Distribution:
Vd:
Not well-defined due to minimal systemic absorption
ProteinBinding:
~67% (human plasma)
CnssPenetration:
Limited
Elimination:
HalfLife:
~5-6 hours (systemic, but low levels)
Clearance:
Primarily fecal
ExcretionRoute:
Fecal (>96% unchanged)
Unchanged:
>96% (in feces)
Pharmacodynamics
OnsetOfAction:
Not precisely defined for local GI effects; clinical improvement for HE typically seen within days, for IBS-D within 14-day course.
PeakEffect:
Not precisely defined for local GI effects.
DurationOfAction:
Dependent on continued dosing for chronic conditions like HE; for IBS-D, effects may persist after 14-day course.
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of a severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), such as:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Swelling in the arms or legs
Swelling of the abdomen
Shortness of breath
Depression
Fever
Diarrhea, especially if it is severe, bloody, or accompanied by stomach pain or cramps (this could be a sign of a rare but potentially life-threatening condition called C. diff-associated diarrhea, or CDAD)
If you experience any of these symptoms, do not try to treat them on your own. Instead, contact your doctor right away for guidance.
Other Possible Side Effects
Like all medications, this drug can cause side effects in some people. While many individuals may not experience any side effects or may only have mild ones, it is essential to be aware of the following possible side effects:
Headache
Feeling dizzy, tired, or weak
Stomach pain
Upset stomach
Muscle spasm
Nose or throat irritation
* Joint pain
If you experience any of these side effects or any other symptoms that concern you, contact your doctor for advice. They can help you determine the best course of action.
Reporting Side Effects
If you have questions or concerns about side effects, you can contact your doctor or report them to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of a severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis), such as:
+ Red, swollen, blistered, or peeling skin (with or without fever)
+ Red or irritated eyes
+ Sores in the mouth, throat, nose, or eyes
Swelling in the arms or legs
Swelling of the abdomen
Shortness of breath
Depression
Fever
Diarrhea, especially if it is severe, bloody, or accompanied by stomach pain or cramps (this could be a sign of a rare but potentially life-threatening condition called C. diff-associated diarrhea, or CDAD)
If you experience any of these symptoms, do not try to treat them on your own. Instead, contact your doctor right away for guidance.
Other Possible Side Effects
Like all medications, this drug can cause side effects in some people. While many individuals may not experience any side effects or may only have mild ones, it is essential to be aware of the following possible side effects:
Headache
Feeling dizzy, tired, or weak
Stomach pain
Upset stomach
Muscle spasm
Nose or throat irritation
* Joint pain
If you experience any of these side effects or any other symptoms that concern you, contact your doctor for advice. They can help you determine the best course of action.
Reporting Side Effects
If you have questions or concerns about side effects, you can contact your doctor or report them to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- New or worsening diarrhea, especially if it's severe, watery, bloody, or accompanied by fever and abdominal cramps (could be a sign of Clostridioides difficile infection).
- Signs of an allergic reaction (e.g., rash, itching, swelling, severe dizziness, trouble breathing).
- Worsening of your original symptoms (e.g., increased confusion, disorientation, or other signs of hepatic encephalopathy; persistent or worsening IBS-D symptoms).
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
If you are experiencing diarrhea accompanied by fever or blood in your stool.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your existing treatments and health issues.
Remember, do not start, stop, or modify the dosage of any medication without first consulting your doctor to ensure your safety.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction and its symptoms.
If you are experiencing diarrhea accompanied by fever or blood in your stool.
This list is not exhaustive, and it is crucial to discuss all your medications (including prescription, over-the-counter, natural products, and vitamins) and health conditions with your doctor and pharmacist. They will help you determine if it is safe to take this medication with your existing treatments and health issues.
Remember, do not start, stop, or modify the dosage of any medication without first consulting your doctor to ensure your safety.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. Adhere to the prescribed duration of treatment, as using this drug for an extended period can increase the risk of a second infection. If you are taking this medication to treat travelers' diarrhea, contact your doctor immediately if your diarrhea persists for more than 24 to 48 hours or worsens. Additionally, if you are pregnant, planning to become pregnant, or are breast-feeding, consult your doctor to discuss the potential benefits and risks of this medication to both you and your baby.
Overdose Information
Overdose Symptoms:
- Due to minimal systemic absorption, overdose is unlikely to cause systemic toxicity. Symptoms would likely be gastrointestinal (e.g., nausea, vomiting, diarrhea).
What to Do:
In case of suspected overdose, contact a poison control center immediately (e.g., 1-800-222-1222 in the US) or seek emergency medical attention. Treatment is generally supportive.
Drug Interactions
Moderate Interactions
- Cyclosporine (co-administration with P-gp inhibitors like cyclosporine can significantly increase systemic exposure of rifaximin, though clinical significance is uncertain)
Minor Interactions
- Warfarin (potential for minor changes in INR, monitor as needed)
Monitoring
Baseline Monitoring
Liver function tests (LFTs)
Rationale: For patients with hepatic encephalopathy, to assess baseline liver status.
Timing: Prior to initiation
Baseline symptoms (HE or IBS-D)
Rationale: To establish a baseline for assessing treatment efficacy.
Timing: Prior to initiation
Routine Monitoring
Clinical response to therapy
Frequency: Ongoing, as clinically indicated
Target: Improvement in HE symptoms (e.g., mental status, asterixis) or IBS-D symptoms (e.g., abdominal pain, stool consistency)
Action Threshold: Lack of improvement or worsening symptoms may require re-evaluation of diagnosis or treatment
Recurrence of symptoms (for HE or IBS-D)
Frequency: Ongoing
Target: Absence of recurrence or reduced frequency/severity of episodes
Action Threshold: Recurrence may indicate need for re-treatment or alternative strategies
Symptom Monitoring
- Worsening or new onset diarrhea (especially if severe, persistent, or bloody, as it may indicate Clostridioides difficile-associated diarrhea (CDAD))
- Fever
- Severe abdominal pain
- Signs of worsening hepatic encephalopathy (e.g., increased confusion, disorientation, asterixis)
- Persistent or worsening IBS-D symptoms (abdominal pain, bloating, diarrhea)
Special Patient Groups
Pregnancy
Category C. There are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
First Trimester:
Animal studies have shown some evidence of developmental toxicity at high doses. Human data are lacking.
Second Trimester:
Human data are lacking.
Third Trimester:
Human data are lacking.
Lactation
It is not known whether rifaximin is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from rifaximin, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Infant Risk:
Risk unknown; caution advised.
Pediatric Use
Safety and effectiveness of Xifaxan 550 mg for hepatic encephalopathy have been established in adolescents aged 16 years and older. Safety and effectiveness for IBS-D have not been established in pediatric patients.
Geriatric Use
No specific dose adjustment is required for elderly patients. Clinical studies did not identify differences in safety or efficacy between elderly and younger patients.
Clinical Information
Clinical Pearls
- Rifaximin's primary action is localized to the gastrointestinal tract due to its very low systemic absorption, making it effective for gut-specific conditions with minimal systemic side effects.
- It is not effective for systemic bacterial infections.
- While rifaximin is an antibiotic, the risk of *Clostridioides difficile*-associated diarrhea (CDAD) exists, though it is considered low compared to systemic antibiotics. Patients developing new or worsening diarrhea should be evaluated for CDAD.
- For hepatic encephalopathy, rifaximin is often used in conjunction with lactulose.
- For IBS-D, rifaximin is typically given as a 14-day course, and re-treatment may be considered for recurrence of symptoms.
Alternative Therapies
- For Hepatic Encephalopathy: Lactulose, Neomycin, Metronidazole
- For IBS-D: Loperamide, Eluxadoline, Alosetron, Probiotics, Dietary modifications (e.g., FODMAP diet)
Cost & Coverage
Average Cost:
$1,000 - $2,000+ per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Tier 2 or Tier 3 (Specialty drug, may require prior authorization)
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to discuss them with your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the medication taken, the amount, and the time it happened.