A Comprehensive Guide to Rifaximin

Names of Medication

The brand name for this medication in the United States is Xifaxan (Rifaximin).

Pharmacologic Category

Rifaximin belongs to the class of medicines known as rifamycins, which are antibiotic medications used to treat or prevent various types of bacterial infections.

Dosing

Rifaximin is used to treat several diseases in adults. Please remember to never adjust the dose of this medication without speaking with your doctor first. Here is a list of diseases that Rifaximin is used to treat, along with the recommended dosages:

Traveler’s Diarrhea caused by noninvasive strains of Escherichia coli

For this condition, the recommended dose is 200 mg taken orally three times a day for three days.

Hepatic Encephalopathy

For the prevention of hepatic encephalopathy, a dose of 550 mg taken orally twice a day is recommended.

Irritable Bowel Syndrome with Diarrhea (IBS-D)

For IBS-D, the recommended dose is 550 mg taken orally three times a day for 14 days. If symptoms recur, treatment can be repeated up to two times.

Small Intestine Bacterial Overgrowth (SIBO)

While not an FDA-approved use, some physicians prescribe Rifaximin for SIBO at a dose of 550 mg taken orally three times a day for 14 days.

Clostridium difficile Infection (off-label use)

For C. difficile, the dosage can vary and treatment is usually guided by the severity of the infection and the patient’s response to therapy.

Dosage Forms and Strengths

Rifaximin comes in the form of tablets and is available in strengths of 200 mg and 550 mg.

Administration Instructions

Rifaximin is an oral medication, usually taken with or without food every 8 to 12 hours, or as directed by your healthcare provider. The tablet should be swallowed whole with water.

Adverse Reactions and Side Effects

Like all medications, Rifaximin can cause side effects, although not everybody gets them. Here are some common and uncommon side effects:

Nausea (Common)

Nausea is a common side effect of many medications, including Rifaximin. This may occur because the medication can irritate the stomach lining or alter digestive processes, leading to a feeling of discomfort or unease in the stomach.

Dizziness (Common)

Rifaximin may cause dizziness in some patients. This can occur because antibiotics can affect the balance of healthy bacteria in your gut, which plays a crucial role in overall health and can impact various bodily functions, including balance.

Swelling of the hands, ankles, or feet (Uncommon)

This side effect may occur due to fluid retention, a condition in which the body’s tissues retain excess fluid. This could be caused by changes in the balance of healthy bacteria in the gut and an inflammatory response to the medication.

Severe allergic reactions (Rare)

Though rare, some people may have an allergic reaction to Rifaximin. This could present as a rash, itching, swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing. These symptoms could be due to the body’s immune system reacting to the medication as a foreign substance.

Contraindications to taking Rifaximin

A contraindication is a condition or factor that serves as a reason to withhold a certain medical treatment due to the harm that it would cause the patient. Here are some contraindications for taking Rifaximin:

Known hypersensitivity to rifamycins

People who have known hypersensitivity to rifamycins, a class of antibiotics that includes Rifaximin, should not take this medication. Hypersensitivity can lead to severe allergic reactions, which can be potentially life-threatening.

Clostridium difficile-associated diarrhea

Rifaximin should not be used to treat Clostridium difficile-associated diarrhea as it can exacerbate the condition. Antibiotics can kill the good bacteria in your gut, allowing Clostridium difficile to grow and produce toxins, leading to severe diarrhea.

Drug to Drug Interactions

Certain medications can interact with Rifaximin, potentially altering its effectiveness and side effect profile. Here are some significant interactions:
Warfarin (Coumadin, Jantoven)
Cyclosporine (Neoral, Sandimmune, Gengraf)
Digoxin (Lanoxin)

Rifaximin in Pregnancy

The FDA classifies Rifaximin as category C for use during pregnancy. This means that risk cannot be ruled out, as there are no adequate and well-controlled studies in pregnant women. As such, Rifaximin should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.

Rifaximin while Breastfeeding

It’s not known whether Rifaximin is excreted into human breast milk or could harm a nursing baby. Therefore, caution should be exercised when considering the use of Rifaximin in nursing mothers.

Estimated Cost of Medication

The cost for Rifaximin oral tablet (200 mg) is around $700 for a supply of 30 tablets, depending on the pharmacy you visit. Prices are for cash-paying customers using a GoodRx coupon and are not valid with insurance plans. Please remember that these prices are only estimates, as prices may vary depending on the pharmacy and location and are subject to change based on negotiated agreements between pharmacies and pharmaceutical companies.

Legal Disclaimer

This article is for informational purposes only and not intended as medical advice. Always consult a healthcare professional for diagnosis and treatment. Reliance on the information provided here is at your own risk.

Brief Legal Disclaimer: This article is for informational purposes only and not intended as medical advice. Always consult a healthcare professional for diagnosis and treatment. Reliance on the information provided here is at your own risk.