Ribavirin, 20 pcs., 200 mg, tablets

Ribavirin

Adult patients

Triple therapy

See prescribing information for boceprevir.

Dual therapy

The safety of ribavirin was assessed in four clinical studies in patients who had not previously taken interferon alfa-2b (patients who had not previously received interferon therapy): two studies examined the use of ribavirin in combination with interferon alfa-2b, two in combination with peginterferon alfa-2b.

Patients previously treated with interferon alfa-2b and ribavirin, or in whom treatment lasted less than the standard duration, may experience an improved safety profile compared to that described below.

The adverse reactions listed below are based on data from clinical studies in interferon-naïve adult patients treated for 1 year and on data from post-marketing use of the drug. A number of adverse reactions, usually attributed to interferon therapy, but also reported with hepatitis C therapy (in combination with ribavirin) are presented below.

Data on adverse reactions presented in the instructions for medical use of peginterferon alfa-2b and interferon alfa-2b may also be applicable to interferon monotherapy.

Adverse reactions are presented by class of organs and systems in decreasing order of frequency according to the following categories: very often (≥1/10); often (≥1/100 to and <1/10); uncommon (≥1/1000 and <1/100); rare (≥1/10000 to <1000); very rare (<1/10000); unknown. Within each frequency group, adverse reactions are presented in order of decreasing severity.

Infectious and parasitic diseases:

very often - viral infections, pharyngitis; often - bacterial infections (including sepsis), fungal infection, influenza, respiratory tract infections, bronchitis, infections caused by the herpes simplex virus, sinusitis, otitis media, rhinitis, urinary tract infections; uncommon - infection at the injection site, lower respiratory tract infection; rarely - pneumonia*.

Benign, malignant and unspecified neoplasms (including cysts and polyps):

often - unspecified neoplasms.

Blood and lymphatic system disorders:

very often - anemia, neutropenia; often - hemolytic anemia, leukopenia, thrombocytopenia, lymphadenopathy, lymphopenia; very rarely - aplastic anemia*; unknown - true erythrocyte aplasia, idiopathic thrombocytopenic purpura, thrombotic thrombocytopenic purpura.

Immune system disorders:

uncommon - hypersensitivity; rare - sarcoidosis*, rheumatoid arthritis (new or worsening); unknown - Vogt-Koyanagi-Harada syndrome, systemic lupus erythematosus, vasculitis, acute hypersensitivity reactions, including urticaria, angioedema, bronchospasm, anaphylaxis.

Endocrine system disorders:

often - hypothyroidism, hyperthyroidism.

Metabolic and nutritional disorders

: very often - anorexia; often - hyperglycemia, hyperuricemia, hypocalcemia, dehydration, increased appetite; uncommon - diabetes mellitus, hypertriglyceremia*.

Mental disorders:

very often - depression, insomnia, emotional lability, anxiety; often - suicidal thoughts, psychosis, aggressive behavior, confusion, agitation, anger, mood swings, pathological behavior, nervousness, sleep disturbances, anxious dreams, decreased libido, apathy, tearfulness; infrequently - suicide attempts, panic attack, hallucinations; rarely - bipolar disorder*; very rarely - suicide*; unknown - homicidal thoughts*, mania*, change in mental status.

Nervous system disorders

: very often - headache, dizziness, dry mouth, difficulty concentrating; often - amnesia, memory impairment, fainting, migraine, ataxia, paresthesia, dysphonia, loss of taste, hypoesthesia, hyperesthesia, hypertonicity, drowsiness, impaired attention, tremor, taste perversion; uncommon - neuropathy, peripheral neuropathy; rarely - seizures (convulsions)*; very rarely - cerebral hemorrhage*, cerebrovascular ischemia*, encephalopathy*, polyneuropathy*; unknown - facial nerve paralysis, mononeuropathy.

Visual disorders:

often - blurred vision, blurred vision, conjunctivitis, eye irritation, eye pain, distortion of visual perception, pathology of the lacrimal glands, dry eyes; rarely - retinal hemorrhages*, retinopathy (including macular edema)*, retinal artery thrombosis*, retinal vein thrombosis*, optic neuritis*, papilledema*, decreased visual acuity or loss of visual fields*, retinal exudate.

Hearing and labyrinth disorders:

often - vertigo, hearing impairment or loss, ringing in the ears, ear pain.

Cardiac disorders:

often - palpitations, tachycardia; uncommon - myocardial infarction; rarely - cardiomyopathy*, arrhythmia*; very rarely - cardiac ischemia*; unknown - pericardial effusion*, pericarditis*.

Vascular disorders:

often - decreased blood pressure, increased blood pressure, “hot flashes”; rarely - vasculitis; very rarely - ischemia of peripheral tissues*.

Disorders of the respiratory system, chest and mediastinal organs:

very often - shortness of breath, cough; often - nosebleeds, respiratory disorders, respiratory tract congestion, sinusitis, swelling of the nasal mucosa, rhinorrhea, increased secretion of the mucous membrane of the upper respiratory tract, sore throat, non-productive cough; very rarely - pulmonary infiltrates*, pneumonitis*, interstitial pneumonitis*.

Gastrointestinal disorders:

very often - diarrhea, vomiting, nausea, abdominal pain; often - ulcerative stomatitis, stomatitis, ulcers in the mouth, colitis, pain in the right upper quadrant of the abdomen, dyspepsia, gastrointestinal reflux*, glossitis, cheilitis, bloating, bleeding gums, gingivitis, frequent loose stools, dental lesions, constipation, flatulence; infrequently - pancreatitis, pain in the oral cavity; rarely - ischemic colitis; very rarely - ulcerative colitis*; unknown - periodontal disorders, dental disorders, tongue pigmentation.

Disorders of the liver and biliary tract

: often - hepatomegaly, jaundice, hyperbilirubinemia *; very rarely - hepatotoxicity (including death)*.

Disorders of the skin and subcutaneous tissues:

very often - alopecia, itching, dry skin, rash; often - psoriasis, worsening of pre-existing psoriasis, eczema, photosensitivity reaction, maculopapular rash, erythematous rash, night sweats, hyperhidrosis, dermatitis, acne, furunculosis, erythema, urticaria, skin disorders, hematoma, increased sweating, hair structure disorder, nail disorders*; rarely - sarcoidosis of the skin; very rarely - Stevens-Johnson syndrome*, toxic epidermal necrolysis*, erythema multiforme and exudative*.

Musculoskeletal and connective tissue disorders:

very often - arthralgia, myalgia, pain in muscles and bones; often - arthritis, back pain, muscle spasms, pain in the limb; uncommon - bone pain, muscle weakness; rarely - rhabdomyolysis*, myositis*.

Renal and urinary tract disorders:

often - frequent urination, polyuria, abnormal urine parameters; rarely - renal dysfunction, renal failure*; very rarely - nephrotic syndrome*.

Disorders of the genital organs and mammary glands:

often - women: amenorrhea, menorrhagia, menstrual irregularities, dysmenorrhea, breast pain, ovarian dysfunction, vaginal disorders; men: impotence, prostatitis, erectile dysfunction, sexual dysfunction (without specifying an exact diagnosis)*.

General disorders and disorders at the injection site:

very often - inflammation at the injection site, reactions at the injection site, fatigue, chills, fever, flu-like symptoms, asthenia, irritability; often - chest pain, chest discomfort, peripheral edema, malaise, pain at the injection site, sensory disturbances, thirst; infrequently - swelling of the face; rarely - necrosis of the injection site.

Laboratory and instrumental data:

very often - weight loss; often - heart murmur.

* Since ribavirin is always prescribed in combination with interferon alfa, and the listed adverse reactions were registered in the post-marketing period, the frequency of reactions cannot be determined. The frequencies listed above are based on data from clinical studies of ribavirin in combination with interferon alfa-2b (pegylated and non-pegylated).

30% of patients taking ribavirin and peginterferon alfa-2b and 37% of patients taking ribavirin and interferon alfa-2b experienced a decrease in hemoglobin concentrations of more than 4 g/dL.

In 14% of adult patients and 7% of children 3 to 18 years of age taking ribavirin in combination with peginterferon alfa-2b or interferon alfa-2b, hemoglobin concentrations decreased to 10 g/dL or lower.

In most cases, mild degrees of anemia, neutropenia and thrombocytopenia (WHO grade 1 or 2) were reported. Some cases of severe neutropenia have been reported in patients taking ribavirin in combination with peginterferon alfa-2b (WHO grade 3: 39 of 186 [21%]; and WHO grade 4: 13 of 186 [7%]); leukopenia grade 3 according to the WHO scale was recorded in 7% of patients from this group.

Increases in uric acid and indirect bilirubin concentrations associated with hemolysis were observed in some patients receiving ribavirin in combination with peginterferon alfa-2b and interferon alfa-2b in clinical studies, but concentrations returned to baseline values ​​4 weeks after completion of treatment. Gout has been reported in a few cases among patients with elevated uric acid concentrations, but none required treatment changes and none were excluded from the clinical trials.

Patients with HCV/HIV co-infection

In patients with HCV/HIV co-infection taking ribavirin in combination with peginterferon alfa-2b, other adverse reactions (not observed in patients with hepatitis C alone) with an incidence of >5% were: oral candidiasis (14%), acquired lipodystrophy (13%), decreased CD4 lymphocyte concentration (8%), decreased appetite (8%), increased gamma-glutamyl transferase activity (9%), back pain (5%), increased blood amylase activity (6%) , increased concentration of lactic acid in the blood (5%), cytolytic hepatitis (6%), increased lipase activity (6%) and pain in the extremities (6%).

Mitochondrial toxicity

Mitochondrial toxicity and lactic acidosis have been reported in HIV-positive patients taking NRTIs and ribavirin for the treatment of hepatitis C (see section 4.4).

Laboratory values ​​in patients with HCV/HIV co-infection

Although hematological disorders such as neutropenia, thrombocytopenia and anemia occurred more often in patients with HCV/HIV co-infection, most of these reactions were correctable by changing the dose and rarely required discontinuation of therapy (see section "Special Instructions"). Hematologic abnormalities were reported more frequently in patients taking ribavirin in combination with peginterferon alfa-2b than in patients taking ribavirin in combination with interferon alfa-2b.

According to the study, a decrease in absolute neutrophil count below 500 cells/mm3, as well as a decrease in platelet count below 50,000/mm3, was observed in 4% (8/194) of patients taking ribavirin in combination with peginterferon alfa-2b.

Anemia (hemoglobin <9.4 g/dL) was reported in 12% (23/194) of patients receiving ribavirin in combination with peginterferon alfa-2b.

Decreased CD4 count

Treatment with ribavirin in combination with peginterferon alfa-2b was associated with a decrease in absolute CD4+ cell counts during the first 4 weeks without a decrease in the percentage of CD4+ cells. The decrease in CD4+ cell counts was reversible after dose reduction or discontinuation of therapy. The use of ribavirin in combination with peginterferon alfa-2b did not have a significant negative effect on the control of HIV viremia during or after treatment. Safety data for co-infected patients with CD4+ cell counts <200/μL are limited (n=25) (see Precautions section).

When taking antiretroviral drugs and drugs for the treatment of HCV together, to identify the specific toxicity of each drug and the development of cross-toxicity of ribavirin and peginterferon alfa-2b, you should read the instructions for medical use of each of the drugs used.

Children from 3 to 18 years (dual therapy only)

In combination with peginterferon alfa-2b

In a clinical study of 107 children (3 to 18 years) receiving combination therapy with peginterferon alfa-2b and ribavirin, dose adjustments were required in 25% of cases, mostly due to anemia, neutropenia, and weight loss.

Overall, the adverse reaction profile in children was consistent with that observed in adults, although the possibility of growth retardation was present.

During combination therapy with pegylated interferon alfa-2b and ribavirin for up to 48 weeks, a decrease in growth rate was observed, resulting in some patients being less than normal in height (see Precautions). Weight loss and growth failure were very common during treatment (at the end of treatment, mean decreases from baseline in weight and height were the 15th and 8th percentiles, respectively); growth velocity was also decreased (<3rd percentile in 70% of patients).

At the end of the 24-week post-treatment follow-up, mean decreases from baseline in weight and height were 3rd and 7th percentiles, respectively, and 20% of children experienced a decrease in height velocity (<3rd percentile). Ninety-four of 107 children participated in the five-year long-term study with follow-up. The effect of the drug on growth was lower in children treated for 24 weeks compared to children treated for 48 weeks. From pre-treatment to end of follow-up, height percentiles for children treated at 24 and 48 weeks decreased by 1.3 and 9.0 percentiles, respectively. Growth loss in 24% of children (11/46) treated for 24 weeks and 40% of children (19/48) treated for 48 weeks was >15th percentile from pre-treatment to the end of the five-year study with follow-up compared to baseline. 11% of children (5/46) treated for 24 weeks and 13% of children (6/48) treated for 48 weeks experienced a decline in height from baseline of more than 30 percentiles of height-for-age. from pre-treatment to the end of the five-year follow-up study. From pretreatment to the end of the five-year follow-up study, weight loss was 1.3 percentile in children treated for 24 weeks and 5.5 percentile in children treated for 48 weeks. Body mass index decreased by 1.8 and 7.5 percentiles, respectively.

In this study, the most common reactions in all patients were fever (80%), headache (62%), neutropenia (33%), fatigue (30%), anorexia (29%), and redness at the injection site (29%). In only 1 patient, treatment was discontinued due to the development of an adverse reaction (thrombocytopenia).

The majority of adverse reactions recorded in this study were mild to moderate in severity. Severe adverse reactions were reported in 7% (8/107) of cases and included pain at the injection site (1%), pain in the extremities (1%), headache (1%), neutropenia (1%) and fever (4%). ).

Significant adverse reactions in this patient population were nervousness (8%), aggression (3%), anger (2%), depression/depressed mood (4%), and underactive thyroid (3%). 5 patients took levothyroxine for hypothyroidism/increased thyroid-stimulating hormone (TSH) concentrations.

In combination with interferon alfa-2b

In a clinical study of 118 children 3 to 18 years of age receiving combination therapy with interferon alfa-2b and ribavirin, 6% discontinued treatment due to adverse reactions. Overall, the adverse reaction profile in a limited population of children 3 to 18 years of age was similar to that observed in adults, however, in the pediatric population, there was concern regarding growth retardation as a decrease in height velocity was observed during treatment (average 9 percentile decrease in height) and body weight (average weight loss 13th percentile). At 5 years of follow-up, the children's mean height was 44 percentile, which was below the normal population mean and less than their mean initial height (48 percentile). Twenty (21%) of 97 children had >15 percentile height decline, of whom 10 of 20 children had >30 percentile height decline from the start of treatment to the end of long-term follow-up (up to 5 years). For 14 of these patients, final height in adulthood (10–12 years after completion of therapy) was known, which showed that 12 patients had a height deficit (greater than 15 percentile).

During combination therapy with interferon alfa-2b and ribavirin for up to 48 weeks, a decrease in growth rate was observed, resulting in some patients being less than normal in height by adulthood. The decrease in mean height percentile compared to baseline at the end of the long-term follow-up period predominated in prepubertal children (see section "Special Instructions").

Moreover, in this group of patients, suicidal ideation and suicide attempts were observed more often than in adults (2.4% compared with 1%) during treatment and during 6-month follow-up. As in adult patients, other mental disorders (for example, depression, emotional lability and drowsiness) also developed in children from 3 to 18 years of age (see section "Special instructions").

In addition, injection site lesions, fever, anorexia, vomiting, and emotional lability were more common in children 3 to 18 years of age compared to adult patients.

Dose changes were required in 30% of cases, mainly due to anemia and neutropenia.

The adverse reactions listed below are based on data from two multicenter clinical studies of ribavirin in combination with interferon alfa-2b or peginterferon alfa-2b in children 3 to 18 years of age.

Infectious and parasitic diseases

: very often - viral infection, pharyngitis; often - fungal infection, bacterial infection, lung infections, nasopharyngitis, streptococcal pharyngitis, otitis media, sinusitis, dental abscess, influenza, oral herpes, infections caused by the herpes simplex virus, urinary tract infections, vaginitis, gastroenteritis; infrequently - pneumonia, ascariasis, enterobiasis, herpes zoster.

Benign, malignant and unspecified neoplasms (including cysts and polyps)

: often - unspecified neoplasms.

Blood and lymphatic system disorders:

very often - anemia, neutropenia; often - lymphadenopathy, thrombocytopenia.

Endocrine system disorders:

very often - hypothyroidism; often - hyperthyroidism, virilism.

Metabolic and nutritional disorders:

very often - anorexia, decreased appetite, increased appetite; often - hypertriglyceridemia, hyperuricemia.

Mental disorders

: very often - depression, insomnia, emotional lability; often - suicidal thoughts, aggressive behavior, confusion, behavioral disorder, agitation, somnambulism, anxiety, mood changes, restlessness, nervousness, sleep disturbance, pathological dreams, apathy; infrequently - behavioral disorders, depressed mood, emotional disorders, fear, disturbing dreams.

Nervous system disorders:

very often - headache, dizziness; often - hyperkinesis, tremor, dysphonia, paresthesia, hypoesthesia, hyperesthesia, impaired concentration, drowsiness, poor quality of sleep; infrequently - neuralgia, lethargy, psychomotor agitation.

Visual disorders:

often - conjunctivitis, eye pain, blurred vision, disorders of the lacrimal glands; infrequently - hemorrhages in the conjunctiva, itching in the eyes, keratitis, blurred vision, photophobia.

Hearing and labyrinth disorders:

often - vertigo.

Cardiac disorders:

often - tachycardia, palpitations.

Vascular disorders:

often - pallor of the skin, “hot flashes”; infrequently - decreased blood pressure.

Disorders of the respiratory system, chest and mediastinal organs:

often - shortness of breath, rapid breathing, nosebleeds, cough, nasal congestion, nasal irritation, rhinorrhea, sore throat; Uncommon: wheezing, nasal discomfort.

Gastrointestinal disorders:

very often - abdominal pain, pain in the upper abdomen, vomiting, diarrhea, nausea; often - oral ulcers, ulcerative stomatitis, stomatitis, aphthous stomatitis, dyspepsia, cheilosis, glossitis, gastroesophageal reflux, rectal disorders, constipation, loose stools, toothache, dental disorders, stomach discomfort, oral pain cavities; infrequently - gingivitis.

Disorders of the liver and biliary tract

: often - liver dysfunction; infrequently - hepatomegaly.

Disorders of the skin and subcutaneous tissues:

very often - alopecia, rash; often - itching, photosensitivity reaction, maculopapular rash, eczema, sweating, acne, skin diseases, nail structure disorders, skin discoloration, dry skin, erythema, hematoma; infrequently - pathological pigmentation, atopic dermatitis, peeling of the skin.

Musculoskeletal and connective tissue disorders:

very often - arthralgia, myalgia, muscle pain; often - pain in the limb, back pain, muscle contractures.

Renal and urinary tract disorders

: often - enuresis, urinary disorders, urinary incontinence, proteinuria.

Disorders of the genital organs and mammary glands

: often - women: amenorrhea, menorrhagia, menstrual irregularities, vaginal disorders; men: testicular pain; infrequently - women: dysmenorrhea.

General disorders and disorders at the injection site:

very often - inflammation at the injection site, reactions at the injection site, erythema at the injection site, pain at the injection site, fatigue, fatigue, fever, chills, flu-like symptoms, asthenia, malaise, irritability; often - chest pain, swelling, itching at the injection site, rash at the injection site, dryness of the injection site, feeling of cold; Uncommon: chest discomfort, pain in the face, hardening of the injection site.

Laboratory and instrumental data:

very often - decreased growth rate (decreased height and/or body weight at a given age); often - increased TSH concentration, increased thyroglobulin concentration; infrequently - positive antibodies to the thyroid gland.

Injuries, intoxications and complications of manipulations

: often - skin damage; infrequently - contusion.

Most changes in laboratory parameters in clinical studies of ribavirin/peginterferon alfa-2b were mild or moderate.

A decrease in the concentration of hemoglobin, leukocytes, platelets, neutrophils and an increase in bilirubin may require dose reduction or discontinuation of therapy (see “Dosage and Administration”). Although changes in laboratory values ​​were observed during treatment with ribavirin/peginterferon alfa-2b in clinical studies, they returned to normal values ​​several weeks after the end of therapy.

If any of the side effects listed in the instructions get worse, or you notice any other side effects not listed in the instructions, tell your doctor.

Ribavirin, capsules

Therapy should be administered by a physician experienced in treating patients with hepatitis C. Ribavirin should not be used as the only drug, as it is not effective as monotherapy for hepatitis C.

Ribavirin is taken orally with food, daily, in two doses (morning and evening).

The dose depends on the patient's body weight.

Table 1. Recommended dosages for adults (based on body weight) when used in combination with interferon alfa-2b or peginterferon alfa-2b.

Duration of treatment in previously untreated patients

Discontinuation of combination therapy with ribavirin should be considered after 12 to 24 weeks of treatment unless the patient has an early virologic response, defined as a negative HCV-RNA test or at least a 2-log reduction in viral load from baseline. at the 12th week of therapy.

Predicting the development of a sustained virological response: In patients infected with hepatitis C virus genotype 1 who have not achieved a virological response at week 12 of treatment, the likelihood of developing a sustained virological response is very low.

• Genotype 1: Patients who demonstrate a virological response at week 12 of treatment should continue therapy for the next 9 months (total 48 weeks). Among patients with HCV genotype 1 and a low viral load (< 2,000,000 copies/ml), in whom the HCV-RNA test result becomes negative at week 4 of treatment and remains negative until week 24. Treatment can either be stopped after a 24-week course or continued for an additional 24 weeks (the duration of treatment is 48 weeks in total). However, a 24-week course of treatment may be associated with a higher risk of relapse than a 48-week course.
• Genotype 2 or 3: The recommended duration of treatment for all patients is 24 weeks.
• Genotype 4\ Patients infected with genotype 4 virus are thought to be more difficult to treat, although limited clinical data (n=66) found similarities in treatment between these patients and patients with genotype 1. Co-infection with HIV and hepatitis C virus I

Duration of treatment is 48 weeks

Prediction of the development of persistent viral response: early virological response at week 12 of treatment (12 log reduction in virological load or HCV-RNA level below detection level) is a prognostic factor for the development of persistent viral response.

virological response. In the negative prognosis group (patients who did not demonstrate an early virological response), 99% of patients did not achieve a sustained virological response when using combination therapy with peginterferon alfa-2b/ribavirin. In the positive prognosis group (patients who demonstrated an early virological response), 50% of patients achieved a durable virological response when using combination therapy.

Duration of treatment if previous therapy fails (patients with relapse or patients who have not responded to treatment)

Prediction of the development of a sustained virological response: all patients with relapse and patients who have not responded to treatment, regardless of genotype, whose serum HCV-RNA level is below the detection level at the 12th week of treatment should receive therapy for the next 9 months ( 48 weeks). Patients who do not achieve a virological response at week 12 of treatment are very unlikely to develop a sustained virological response.

Recommended doses when used in combination with interferon alpha-2b: for body weight less than 75 kg - 1000 mg/day (2 capsules in the morning and 3 in the evening), for body weight more than 75 kg - 1200 mg/day (3 capsules in the morning and 3 capsules In the evening).

Duration of treatment: based on clinical experience

studies, the recommended duration of treatment is at least 6 months. During these clinical studies, patients were treated for a year and patients who did not achieve a virological response after 6 months of therapy (HCV-RNA below detection level) were likely to develop a sustained virological response (HCV-RNA below detection level for 6 months after the end of treatment). course of therapy) was very low.

• genotype 1: treatment is continued for the next 6 months (1 year in total) in those patients who have eliminated hepatitis C virus RNA from the blood serum by the end of the first 6 months of treatment.
• genotype not 1: The decision to extend therapy to 1 year in patients who are HCV-RNA negative after 6 months of treatment should be based on other prognostic factors (eg, patient age > 40 years, male gender, presence of fibrosis).

Table 2. Recommended dosages for children (based on body weight) when used in combination with interferon alfa-2b or peginterferon alfa-2b

For children who weigh less than 47 kg or who are unable to swallow capsules, it is recommended that oral liquid ribavirin be given.

Duration of therapy in children

Genotype 1. The recommended duration of treatment with two drugs is 1 year. Based on extrapolation from clinical data on combination therapy with standard interferon in children (negative outcome rate of 96% for interferon alfa-2b/ribavirin), achieving sustained virological response in patients who have not achieved virological response by week 12 is extremely unlikely. Therefore, it is recommended to discontinue treatment in children and adolescents receiving the combination of interferon alfa-2b (pegylated or non-pegylated) and ribavirin if hepatitis C virus RNA levels are <2 logio below baseline at week 12, or if at week 24 hepatitis C virus RNA levels are detected in the week.

Genotype 2 or 3. The recommended duration of treatment with both drugs is 24 weeks.

Genotype 4. In clinical studies, only 5 children and adolescents with genotype 4 were treated with the peginterferon alfa-2b/ribavirin combination. The recommended duration of treatment with both drugs is 1 year. It is recommended to discontinue treatment in adolescents receiving the combination of peginterferon alfa-2b and ribavirin if hepatitis C virus RNA levels are <2 logio from baseline at week 12 or if hepatitis C virus RNA levels are detected at week 24 .

Dose modification for all patients

Combination therapy. If severe adverse reactions or pathological laboratory abnormalities occur during combination therapy with Ribavirin and peginterferon alfa-2b, or interferon alfa-2b, or Ribavirin, peginterferon alfa-21) and boceprevir, the dosage should be modified (as indicated in Table 3 ) until the adverse reactions disappear. A dose reduction of boceprevir is not recommended. Guidelines for dose modification were developed during clinical studies (see Table 3). Because adherence to the treatment regimen may be important to the outcome of therapy, the dose should be kept as close as possible to the recommended standard dose. A potential negative impact of ribavirin dose reduction on efficacy results cannot be excluded.

Ribavirin, 20 pcs., 200 mg, tablets

Absorption: When administered orally, ribavirin is rapidly absorbed from the gastrointestinal tract. Moreover, its bioavailability is more than 45%.

Distribution: ribavirin is distributed in plasma, secretions of the respiratory tract mucosa and erythrocytes. Large amounts of ribavirin triphosphate accumulate in red blood cells, reaching a plateau by day 4 and persisting for several weeks after administration. The half-life of distribution is 3.7 hours. The volume of distribution (Vd) is 647 – 802 l. During a course of treatment, ribavirin accumulates in the plasma in large quantities. The ratio of bioavailability indicators (AUC - area under the concentration/time curve) for repeated and single doses is 6. A significant concentration of ribavirin (more than 67%) can be detected in the cerebrospinal fluid after long-term use. Slightly binds to plasma proteins.

The time to reach maximum plasma concentration is from 1 to 1.5 hours.

The time to reach therapeutic plasma concentrations depends on the minute volume of blood.

Average maximum concentration (Cmax) in plasma: about 5 µmol per liter at the end of 1 week of administration at a dose of 200 mg every 8 hours and about 11 µmol per liter at the end of 1 week of administration at a dose of 400 mg every 8 hours.

Biotransformation: ribavirin is phosphorylated in liver cells into active metabolites in the form of mono-, di- and triphosphate, which are then metabolized to 1,2,4-triazolecarboxamide (amide hydrolysis to tricarboxylic acid and deribosylation to form a triazole carboxyl metabolite).

Elimination: Ribavirin is excreted slowly from the body. The half-life (T1/2) after a single dose of 200 mg is 1 to 2 hours from plasma and up to 40 days from red blood cells. After stopping the course of treatment, T1/2 is about 300 hours. Ribavirin and its metabolites are mainly excreted from the body in the urine. Only about 10% is excreted in the feces. In unchanged form, about 7% of ribavirin is eliminated in 24 hours and about 10% in 48 hours.

Pharmacokinetics in special clinical conditions: When taking the drug in patients with renal failure, the AUC and Cmax of ribavirin increase, which is due to a decrease in true clearance. In patients with liver failure (grades A, B and C), the pharmacokinetics of ribavirin does not change. After taking a single dose with a meal containing fat, the pharmacokinetics of ribavirin changes significantly (AUC and Cmax increase by 70%).