Ribavirin

Ribavirin capsules are a nucleoside analogue indicated in combination with interferon alfa-2b (pegylated and nonpegylated) for the treatment of Chronic Hepatitis C (CHC) in patients 3 years of age or older with compensated liver disease. ( 1.1 ) Patients with the following characteristics are less likely to benefit from re-treatment after failing a course of therapy: previous nonresponse, previous pegylated interferon treatment, significant bridging fibrosis or cirrhosis, and genotype 1 infection. …

• Ribavirin capsules are administered according to body weight
• Dose reduction or discontinuation is recommended in patients experiencing certain adverse reactions or renal dysfunction
• General Dosing Information Do not open, crush or break ribavirin capsules
• Ribavirin capsules should be taken with food [see Clinical Pharmacology ]
• Ribavirin capsules/PegIntron Combination Therapy Adult Patients The recommended dose of ribavirin capsules when used in combination with PegIntron is 800 mg to 1,400 mg based on patient body weight in two divided doses (see Table 1)
• Refer to PegIntron labeling for PegIntron dosing information
• Duration of Treatment – Interferon Alpha-naïve Patients The treatment duration for patients with genotype 1 is 48 weeks
• Discontinuation of therapy should be considered in patients who do not achieve at least a 2 log 10 drop or loss of hepatitis C virus (HCV)-RNA at 12 weeks, or if HCV-RNA remains detectable after 24 weeks of therapy
• Patients with genotype 2 and 3 should be treated for 24 weeks
• Duration of Treatment – Re-treatment with PegIntron/Ribavirin capsules of Prior Treatment Failures The treatment duration for patients who previously failed therapy is 48 weeks, regardless of HCV genotype
• Re-treated patients who fail to achieve undetectable HCV-RNA at Week 12 of therapy, or whose HCV-RNA remains detectable after 24 weeks of therapy, are highly unlikely to achieve SVR and discontinuation of therapy should be considered [see Clinical Studies ]. …

Ribavirin Capsules USP, 200 mg are white/white, size ‘1’ hard gelatin capsule filled with white to off-white granular powder and imprinted with ‘E’ on white cap and ‘81’ on white body with black ink. Ribavirin Capsules USP 200 mg ( 3 )

• Safety and effectiveness of ribavirin in combination with PegIntron has not been established
• In pediatric patients below the age of 3 years
• For treatment with ribavirin/INTRON A, evidence of disease progression, such as hepatic inflammation and fibrosis, as well as prognostic factors for response, HCV genotype and viral load should be considered when deciding to treat a pediatric patient
• The benefits of treatment should be weighed against the observed safety findings. …

Clinical trials of ribavirin combination therapy did not include sufficient numbers of subjects aged 65 and over to determine if they respond differently from younger subjects. Ribavirin is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients often have decreased renal function, care should be taken in dose selection. …

• Advise the patient to read the FDA-approved patient labeling ( Medication Guide )
• Anemia The most common adverse experience occurring with ribavirin capsules is anemia, which may be severe [see Warnings and Precautions and Adverse Reactions ]
• Advise patients that laboratory evaluations are required prior to starting therapy and periodically thereafter [see Dosage and Administration ]
• Advise patients to be well hydrated, especially during the initial stages of treatment
• Embryo-Fetal Toxicity Inform females of reproductive potential and pregnant women that ribavirin capsules may cause birth defects, miscarriage, and stillbirth. …

• Ribavirin capsules combination therapy is contraindicated in: pregnancy
• Ribavirin capsules may cause fetal harm when administered to a pregnant woman
• Ribavirin capsules are contraindicated in women who are pregnant or planning to become pregnant
• If a patient becomes pregnant while taking ribavirin capsules, the patient should be apprised of the potential hazard to the fetus [see Warnings and Precautions , and Use in Specific Populations ]. …

Nucleoside analogues: Closely monitor for toxicities. Discontinue nucleoside reverse transcriptase inhibitors or reduce dose or discontinue interferon, ribavirin or both with worsening toxicities. ( 7.2 ) 7.1 Didanosine Exposure to didanosine or its active metabolite (dideoxyadenosine 5’-triphosphate) is increased when didanosine is coadministered with ribavirin, which could cause or worsen clinical toxicities; therefore, coadministration of ribavirin capsules and didanosine is contraindicated [see Contraindications (4) ] . Reports of fatal hepatic failure, as well as peripheral neuropathy, pancreatitis, and symptomatic hyperlactatemia/lactic acidosis have been reported in clinical trials. …

Embryo-Fetal Toxicity: May cause fetal harm. Patients should have a negative pregnancy test prior to therapy and use effective contraception and undergo periodic pregnancy tests. ( 5.1 , 8.1 , 8.3 ) Patients exhibiting the following conditions should be closely monitored and may require dose reduction or discontinuation of therapy: Hemolytic anemia may occur with a significant initial drop in hemoglobin. ( 5.2 ) Pancreatitis. ( 5.3 ) Pulmonary infiltrates or pulmonary function impairment. ( 5.4 ) New or worsening ophthalmologic disorders. ( 5.5 ) Severe decreases in neutrophil and platelet counts, and hematologic, endocrine (e.g., TSH), and hepatic abnormalities. …

The following serious adverse drug reactions are discussed in other sections of the labeling: Embryo-Fetal Toxicity [see Warnings and Precautions (5.1) ] Anemia [see Warnings and Precautions (5.2) ] Pancreatitis [see Warnings and Precautions (5.3) ] Pulmonary Disorders [see Warnings and Precautions (5.4) ] Ophthalmic Disorders [see Warnings and Precautions (5.5) ] Dental and Periodontal Disorders [see Warnings and Precautions (5.7) ] Impact on Growth in Pediatric Patients [see Warnings and Precautions (5.9) ] Hemolytic anemia occurred in more than 10% of adult patients receiving ribavirin/PegIntron or INTRON A combination therapy. …

8.1 Pregnancy Risk Summary Ribavirin is contraindicated for use in pregnant women and in men whose female partners are pregnant [see Contraindications (4) ] . Based on animal data, ribavirin use in pregnancy may be associated with birth defects. Data from the Ribavirin Pregnancy Registry are insufficient to identify a drug-associated risk of birth defects, miscarriage, or adverse maternal or fetal outcomes (see Data) . …

There is limited experience with overdosage. Acute ingestion of up to 20 g of ribavirin capsules, INTRON A ingestion of up to 120 million units, and subcutaneous doses of INTRON A up to 10 times the recommended doses have been reported. Primary effects that have been observed are increased incidence and severity of the adverse reactions related to the therapeutic use of INTRON A and ribavirin. …

Take it when you remember, unless it is nearly time for the next dose. Then skip the missed one. Never take two doses at once to make up for it. Check your leaflet, as some medicines are different.