Rifarex
Rifarex Uses, Dosage, Side Effects, Food Interaction and all others data.
Rifarex is a non-aminoglycoside semi-synthetic antibacterial derived from rifamycin SV. It inhibits bacterial RNA synthesis by binding to the bacterial DNA-dependent RNA polymerase and has antibacterial activity against Escherichia coli (E. coli).
Rifarex is a structural analog of rifampin and a non-systemic, gastrointestinal site-specific antibiotic. This non-systemic property of the drug is due to the addition of a pyridoimidazole ring, which renders it non-absorbable. Rifarex acts by inhibiting bacterial ribonucleic acid (RNA) synthesis and contributes to restore intestinal microflora imbalance. Other studies have also shown rifaximin to be an pregnane X receptor (PXR) activator. As PXR is responsible for inhibiting the proinflammatory transcription factor NF-kappa B (NF-κB) and is inhibited in inflammatory bowel disease (IBD), rifaximin was proven to be effective for the treatment of IBS-D.
| Trade Name | Rifarex |
| Availability | Prescription only |
| Generic | Rifaximin |
| Rifaximin Other Names | Rifaxidin, Rifaximin, Rifaximina, Rifaximine, Rifaximinun |
| Related Drugs | ciprofloxacin, dicyclomine, sulfamethoxazole / trimethoprim, Bactrim, loperamide, lactulose, Bentyl, hyoscyamine, Xifaxan, Imodium |
| Type | Tablet |
| Formula | C43H51N3O11 |
| Weight | Average: 785.8785 Monoisotopic: 785.352359489 |
| Groups | Approved, Investigational |
| Therapeutic Class | Miscellaneous Antibiotics |
| Manufacturer | Tas Med India Pvt Ltd |
| Available Country | India |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Acute infectious diarrhoea including travelers diarrhoea, Diarrhoea predominant Irritable Bowel Syndrome (IBS-D), Hepatic Encephalopathy (H.E.)
Rifarex is also used to associated treatment for these conditions: Bacterial Infections, Clostridium difficile infection recurrence, Hepatic Encephalopathy (HE), Irritable Bowel Syndrome (IBS), Traveler's Diarrhea
How Rifarex works
Rifarex acts by inhibiting RNA synthesis in susceptible bacteria by binding to the beta-subunit of bacterial deoxyribonucleic acid (DNA)-dependent ribonucleic acid (RNA) polymerase enzyme. This binding blocks translocation, which stops transcription.
Dosage
Rifarex dosage
Acute Infectious Diarrhoea including Travelers’ Diarrhoea: 200 mg three times daily for 3 days.
Diarrhoea predominant Irritable Bowel Syndrome (IBS-D): 550 mg three times daily for 14 days.
Hepatic Encephalopathy (H.E.): 550 mg twice daily
Side Effects
Common side effects are nausea, vomiting, abdominal pain, flatulence, headache and dizziness.
Toxicity
LD50 > 2 g/kg (orally, in rats)
Precaution
Pregnancy and lactation. Caution in severe hepatic impairment (Child-Pugh class C). Not effective against diarrhoea caused by pathogen other than E. coli ; or diarrhoea complicated by fever and/or blood in the stool. Prolonged use may result in Clotridum difficile-associated diarrhoea. Severe hepatic impairment (Child-pugh class C).
Interaction
Although In vitro studies demonstrated the potential of Rifarex to interact with cytochrome P450 (CYP3A4), a clinical drug-drug interaction study demonstrated that Rifarex did not significantly affect the pharmacokinetics of midazolam. An additional clinical drug-drug interaction study showed no effect of Rifarex on the presystemic metabolism of an oral contraceptive containing ethinyl estradiol and norgestimate. Therefore, clinical interactions with drugs metabolized by human cytochrome P450 isozymes are not expected.
Food Interaction
- Take with or without food. Fatty meals may increase the systemic AUC of rifaximin, but do not impact Cmax. Rifarex is an antibacterial used for local action in the gastrointestinal tract; therefore, changes in systemic exposure may not significantly impact efficacy.
Rifarex Drug Interaction
Unknown: aspirin, lorazepam, amoxicillin / clavulanate, diphenhydramine, duloxetine, metronidazole, furosemide, pregabalin, polyethylene glycol 3350, esomeprazole, acetaminophen, pantoprazole, acetaminophen, cyanocobalamin, ascorbic acid, cholecalciferol, alprazolam, ondansetron, sertraline, cetirizine
Rifarex Disease Interaction
Elimination Route
Low absorption in both the fasting state and when administered within 30 minutes of a high-fat breakfast.
Half Life
Approximately 6 hours.
Elimination Route
In a mass balance study, after administration of 400 mg 14C-rifaximin orally to healthy volunteers, of the 96.94% total recovery, 96.62% of the administered radioactivity was recovered in feces almost exclusively as the unchanged drug and 0.32% was recovered in urine mostly as metabolites with 0.03% as the unchanged drug.Rifarex accounted for 18% of radioactivity in plasma. This suggests that the absorbed rifaximin undergoes metabolism with minimal renal excretion of the unchanged drug
Pregnancy & Breastfeeding use
Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. Rifarex should be used during pregnancy only if the potential benefit outweighs the potential risk to the fetus.
Use in Lactation: It is not known whether Rifarex is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for adverse reactions in nursing infants from Rifarex, 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.
Contraindication
Rifarex is contraindicated in patients with a hypersensitivity to Rifarex, or any of the Rifamycin antimicrobial agents, or any of the components of Rifarex.
Special Warning
Use in Children: The safety and effectiveness of Rifarex 200 mg in pediatric patients with travelers’ diarrhoea less than 12 years of age have not established.The safety and effectiveness of Rifarex 550 mg for hepatic encephalopathy have not been established in patients <18 years of age.
Use in geriatric patients: Clinical studies of Rifarex tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently than younger subjects.
Use in Renal Insufficient Patients:The pharmacokinetics of Rifarex in patients with impaired renal function has not been studied.
Use in Hepatic Insufficient Patients:No dosage adjustment with Rifarex is necessary due to its limited systemic absorption. Nonetheless, caution should be exercised when Rifarex is administered to patients with severe hepatic impairment.
Acute Overdose
No specific information is available on the treatment of over dosage with Rifarex. In case of over dosage, discontinue Rifarex, treat symptomatically and institute supportive measures as required.
Storage Condition
Store at 20-25° C; excursions permitted to 15-30° C.
Innovators Monograph
You find simplified version here Rifarex
Rifarex contains Rifaximin see full prescribing information from innovator Rifarex Monograph, Rifarex MSDS, Rifarex FDA label
FAQ
What is Rifarex used for?
Rifarex is used to treat traveler's diarrhea that is caused by a bacteria called Escherichia coli. It is also used to prevent hepatic encephalopathy, which is a condition that occurs when your liver does not work normally.Rifarex is also used to treat irritable bowel syndrome with diarrhea.
How safe is Rifarex?
Rifarex is safe and well tolerated for long-term maintenance of remission from overt hepatic encephalopathy.
How does Rifarex work?
Rifarex treats traveler's diarrhea and irritable bowel syndrome by stopping the growth of the bacteria that cause diarrhea. Rifarex treats hepatic encephalopathy by stopping the growth of bacteria that produce toxins and that may worsen liver disease.
What are the common side effects of Rifarex?
Common side effects of Rifarex are include:
- Gas (flatulence)
- Headache
- Feeling as if your bowels are not completely emptied
- Feeling you need to urgently empty your bowels
- Abdominal or stomach pain
- Nausea
- Constipation
- Fever
- Vomiting
- Bloating
- Dizziness
- Tired feeling
- Swelling in your hands, feet, or torso
Is Rifarex safe during pregnancy?
There are no adequate and well controlled studies in pregnant women.Rifarex tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Is Rifarex safe during breastfeeding?
Rifarex is poorly absorbed orally and used only for gastrointestinal infections. It is not likely to reach the breastmilk or bloodstream of the infant or cause any adverse effects in breastfed infants after maternal use.
When Is the best taken of Rifarex?
Rifarex usually 2 times a day (every 12 hours).Take this medication at the same time(s) every day.
Can I take Rifarex on an empty stomach?
Rifarex should be taken on an empty stomach.
Should Rifarex be taken with food?
You may take this medicine with or without food.
Is Rifarex strong antibiotic?
Rifarex is a gastrointestinal-selective antibiotic with a broad spectrum of antimicrobial activity, an excellent safety profile, minimal drug interactions, and negligible impact on the intestinal microbiome.
How fast does Rifarex work?
After just two weeks of treatment, relief lasted for up to 6 months.
Who should not take Rifarex?
You should not take Rifarex if you are allergic to Rifarex. Tell your doctor if you have ever had.Tell your doctor if you are pregnant or breastfeeding.Rifarex should not be given to a child younger than 12 years old.
Is Rifarex safe for liver?
Rifarex could theoretically prevent SBP in patients with liver cirrhosis by reducing gut bacteria.
Can Rifarex help constipation?
The antibiotic Rifarex is used to treat non-constipated irritable bowel syndrome (IBS).
How long can I take Rifarex?
You may take Rifarex with or without food. For travelers' diarrhea, Rifarex is usually taken for only 3 days.
Is Rifarex safe for kidneys?
While the effects of Rifarex have been shown to be protective against acute kidney injury and hepatorenal syndrome in alcohol-induced cirrhosis, its long-term effects on the renal function of other cirrhotic patients are unknown.
What happens if I miss a dose of Rifarex?
Take Rifarex as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What should I avoid while taking Rifarex?
Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor before using anti-diarrhea medicine.
How many Rifarex can Rifarex take in a day?
Adults and children 12 years of age and older 200 milligrams (mg) three times a day for 3 days. Children younger than 12 years of age.Use and dose must be determined by your doctor.
