Alfa normix® [Rifaximin]

Pharmacological properties

rifaximin - a broad-spectrum antibiotic, is a semisynthetic derivative of rifamycin sv. irreversibly binds the β-subunits of the bacterial enzyme, dna-dependent rna polymerase and, therefore, inhibits the synthesis of rna and bacterial proteins. as a result of irreversible binding to the enzyme, rifaximin exhibits bactericidal properties against sensitive bacteria.

The drug has a wide spectrum of antibacterial activity, including most gram-negative and gram-positive, aerobic and anaerobic bacteria that cause gastrointestinal infections, including travelers diarrhea.

Gram negative

Aerobes: Salmonella spp., Shigella spp., Escherichia coli, including enteropathogenic strains, Proteus spp., Campylobacter spp., Pseudomonas spp., Yersinia spp., Enterobacter spp., Klebsiella spp., Helicobacter pylori;

anaerobes: Bacteroides spp., including Bacteroides fragilis, Fusobacterium nucleatum;

Gram positive

aerobes: Streptococcus spp., Enterococcus spp., including Enterococcus fecalis, Staphylococcus spp .;

anaerobes: Clostridium spp., including Clostridium difficile and Clostridium perfrigens, Peptostreptococcus spp.

The absorption of rifaximin in polymorphic form α in the gastrointestinal tract when administered orally is negligible (1%). The antibiotic acts locally in the intestine, where its high concentration is achieved, significantly higher than the minimum inhibitory concentration for the tested enteropathogenic microbes (after 3 days of therapy, the level of feces 4000-8000 μg / g when taking a daily dose of 800 mg is reached). Due to this, rifaximin has a pronounced antibacterial effect. The use of the drug helps to reduce the pathogenic intestinal bacterial flora, which causes some pathological conditions or is involved in their pathogenesis.

The drug reduces:

the formation by bacteria of ammonia and other toxic compounds, which in the case of severe liver disease, accompanied by a violation of the detoxification process, are involved in the pathogenesis of hepatic encephalopathy;

increased proliferation of bacteria with the syndrome of excessive growth of microorganisms in the intestine;

the presence in the diverticulum of the intestine of bacteria that can participate in inflammation in and around the diverticulum and possibly play a key role in the development of symptoms and complications of diverticulosis;

antigenic stimuli, which in the presence of genetically determined defects in the immunoregulation of the mucosa and / or in the protective function, can induce or constantly support chronic intestinal inflammation;

the risk of infectious complications in colorectal surgery.

Due to the practically absent absorption of rifaximin in the digestive tract, there is no risk of systemic side effects. In numerous clinical trials, rifaximin has always been well tolerated by patients.

Pharmacokinetics Rifaximin absorption by ingestion of 1%, based on data from pharmacokinetic studies in rats, dogs and humans.

The drug is not detected in blood plasma after administration in therapeutic doses (detection limit 0.5–2 ng / ml) or is found in very low concentrations (less than 10 ng / ml in almost all cases) both in healthy volunteers and in patients with damaged intestinal mucosa (as a result of ulcerative colitis or Crohns disease). Rifaximin found in urine is not more than 0.5% of the oral dose.

Almost all rifaximin taken by mouth is located in the digestive tract, where very high drug concentrations are achieved (concentrations in feces 4000–8000 μg / g are reached after 3 days of taking the drug in a daily dose of 800 mg). Comparative pharmacokinetic studies have shown that polymorphic forms of rifaximin are absorbed in the intestine in a greater amount than polymorphic form α.

Indications

Treatment of gastrointestinal infections caused by bacteria sensitive to rifaximin:

acute gastrointestinal infections (including travelers diarrhea);

syndrome of excessive growth of microorganisms in the small intestine;

hepatic encephalopathy;

diverticulitis in the acute stage and chronic inflammation of the intestine.

Prevention of infectious complications in colorectal surgery.

Application

Suspension

Adults and children over the age of 12 years: from 10 ml of an oral suspension 3 times a day to 20 ml of an oral suspension 2-3 times a day (600-1200 mg of rifaximin).

Children aged 6 to 12 years: from 10 ml of an oral suspension 2-3 times a day to 20 ml of an oral suspension 2 times in knocking (400-800 mg of rifaximin).

Children aged 2 to 6 years: from 5 ml of an oral suspension 2-3 times a day to 10 ml of an oral suspension 3 times a day (200-600 mg of rifaximin).

For the treatment of adults and children over 6 years of age, instead of an oral suspension, Alfa normix in the form of 200 mg film-coated tablets can be used.

Tablets

Adults and children over the age of 12 years: from 1 tablet 3 times a day to 2 tablets 2-3 times a day (600-1200 mg of rifaximin).

Children aged 6 to 12 years: from 1 tablet 2-3 times a day to 2 tablets 2 times a day (400-800 mg of rifaximin).

The duration of treatment should not exceed 7 days and depends on the clinical effect in patients.

If necessary, repeated courses of treatment can be carried out with an interval of 20-40 days.

The total duration of therapy depends on the adequacy of the clinical effect in patients.

Doses and frequency of administration may be changed on the recommendation of a doctor.

Suspension preparation

Granules for the preparation of oral suspension are in a hermetically sealed vial. The bottle must be opened, add water to the label and shake well. Add water again until the slurry reaches the specified level.

The concentration of rifaximin in the finished suspension is 100 mg per 5 ml. For measuring 5; A 10 or 15 ml suspension is added to a measuring cup.

The suspension remains stable for 7 days at room temperature. Before taking the drug, the vial must be shaken well.

Contraindications

Hypersensitivity to rifaximin, or to other rifamycins, or to any of the components of the drug.

Side effects

Analysis of safety data showed that the risk of side effects when using Alfa normix is ​​very low. these phenomena are limited mainly by disorders of the gastrointestinal tract (nausea, dyspepsia, vomiting, pain and abdominal cramps), are mild or moderate, and usually resolve independently without the need to change the dose or suspend therapy.

The drug is practically not absorbed in the digestive tract, which eliminates the risk of developing systemic side effects.

In rare cases, skin reactions like urticaria may occur, which are probably associated with individual treatment intolerance. The risk of side effects is 0.7–2% of all cases of drug use. Post-marketing surveillance data confirm the above risk assessment and the nature of the observed phenomena.

special instructions

During prolonged treatment with high doses or with damage to the intestinal mucosa, a small amount of the drug (1%) may be absorbed, which can cause urine to stain reddish. this is due to the active substance, which, like most antibiotics of this series (rifamycins), has a red-orange color.

Use during pregnancy and lactation. Rifaximin did not cause teratogenic effects in rats and rabbits. Adequate data and well-controlled studies of pregnant women are not available.

Since the study of toxicity on reproductive function in animals does not allow assessing the possibility of a toxic effect in humans, during pregnancy, the drug can be taken only in case of urgent need and under the direct supervision of a doctor.

The penetration of rifaximin into breast milk has not been studied, but it is presumably insignificant due to very low absorption into the systemic circulation. Therefore, the use of Alfa normix by women who are breastfeeding is allowed with appropriate medical supervision.

The ability to influence the reaction rate when driving vehicles or other mechanisms. Not installed.

Interactions

Not installed.

Overdose

Signs of an overdose were not observed when taking Alfa normix in doses up to 2400 mg per day for 5 days.

In case of an overdose, gastric lavage and symptomatic treatment are recommended.

Storage conditions

Store the prepared suspension at a temperature not exceeding 30 ° c.