). 4. 1 Dosing Considerations Due to the limited systemic absorption of ZAXINE (rifaximin), no specific dosing adjustment is recommended for patients with mild to moderate hepatic insufficiency. Although no dosage adjustment is recommended at this time, caution should be exercised when ZAXINE is administered to patients with severe (Child-Pugh C) hepatic impairment and in patients with MELD score ≥25 (see 10 CLINICAL PHARMACOLOGY, Pharmacokinetics).
While taking ZAXINE with food has resulted in small increases in systemic exposure in healthy subjects, the effects of food on ZAXINE exposure in hepatic impairment patients have not been studied. However, since the absolute systemic bioavailability of rifaximin is still relatively low and the drug works locally in the gastrointestinal tract, rifaximin can be given with or without food.
Treatment duration beyond 6 months should take into consideration the individual balance between benefits and risks, including those associated with the progression of hepatic dysfunction and increasing systemic exposure to rifaximin.
2 Recommended Dose and Dosage Adjustment Hepatic Encephalopathy The recommended dose of ZAXINE is one 550 mg tablet taken orally two times a day. No more than two doses of ZAXINE (1 tablet twice a day) should be taken in a 24-hour period.
Irritable Bowel Syndrome with Diarrhea The recommended dose of ZAXINE is one 550 mg tablet taken orally three times a day for 14 days. In the trials of ZAXINE for IBS-D, patients who experienced a recurrence of symptoms and who responded to a first treatment were safely and effectively retreated for up to 2 times.
Current clinical trials have not evaluated the safety and efficacy of three or more repeat treatments for IBS-D. No more than three doses of ZAXINE (1 tablet three times a day) should be taken in a 24-hour period. 4 Administration ZAXINE can be taken with or without food (see 10 CLINICAL PHARMACOLOGY, Pharmacokinetics, Table 7).
Tablets should be swallowed whole. 5 Missed Dose If a dose is missed, it should be taken as soon as possible. However, if it is almost time for the next dose, no additional dose should be taken and the regular dosing schedule should be Product Monograph ZAXINE, Rifaximin Tablets Page 6 of 36 resumed.
5. OVERDOSAGE No specific information is available on the treatment of overdosage with ZAXINE (rifaximin). , > 1100 mg/day for HE and 1650 mg/day for IBS-D [up to a daily maximum of 2400 mg rifaximin]), adverse reactions were similar in subjects receiving ZAXINE or placebo.
In the case of overdosage, discontinue ZAXINE, treat symptomatically, and institute supportive measures as required. 6. DOSAGE FORMS, STRENGTHS, COMPOSITION AND PACKAGING Table 1 – Dosage Forms, Strengths, Composition and Packaging ZAXINE (rifaximin) 550 mg is a pink, oval, biconvex tablet with “rfx” debossed on one side.
It is available in bottles of 60 tablets. 7 WARNINGS AND PRECAUTIONS General Not for Systemic Infections ZAXINE (rifaximin) acts locally on the microflora of the gut and should not be used for the treatment of systemic bacterial infections.
Low systemic absorption of rifaximin has been noted in healthy individuals, but absorption is increased in subjects with impaired hepatic function. (See 7 WARNINGS AND PRECAUTIONS, Hepatic/Biliary/Pancreatic). There is the potential for increased systemic exposure to rifaximin in disease states in which intestinal barrier function or gut motility is altered.
7-fold increases in Cmax and AUC, respectively) than in healthy subjects receiving the same doses. Route of Administration Dosage Form / Strength/Composition Non-medicinal Ingredients Oral Tablets: 550 mg colloidal silicon dioxide, glyceryl distearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, red iron oxide, gluten-free sodium starch glycolate, talc, and titanium dioxide.
If you think you, or a person you are caring for, have taken too much ZAXINE, contact a healthcare professional, hospital emergency department, or regional poison control centre immediately, even if there are no symptoms. Product Monograph ZAXINE, Rifaximin Tablets Page 7 of 36 The effect on the gut flora following long-term use of rifaximin is not known.
Carcinogenesis and Mutagenesis A possible relationship between Zaxine treatment and carcinogenicity cannot be ruled out. 2 times the recommended human dose, based on relative body surface area comparisons) showed an increased trend in malignant schwannomas of the heart in male rats, but not female rats.
Gastrointestinal Clostridium difficile-Associated Disease Clostridium difficile-associated disease (CDAD) has been reported with use of nearly all antibacterial agents, including ZAXINE (see 8 ADVERSE REACTIONS), and may range in severity from mild diarrhea to fatal colitis.
Treatment with antibacterial agents alters the normal flora of the colon which may lead to overgrowth of C. difficile. C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C.
difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use.
Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued.
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