Child: As 20 mg/mL soln: 300 mL (6 g) delivered via small particle aerosol generator over 12-18 hr daily for 3-7 days. Average aerosol concentration: 190 mcg/L of air.
Oral Chronic hepatitis C
Adult: Rebetol (Schering-Plough) <65 kg: 400 mg both morning and evening; 65-80 kg: 400 mg in the morning and 600 mg in the evening; 81-105 kg: 600 mg both morning and evening; >105 kg: 600 mg in the morning and 800 mg in the evening. Use in combination w/ interferon alfa-2b or peginterferon alfa-2b. Copegus (Roche) Mono-infection (genotype 1 or 4): <75 kg: 400 mg in the morning and 600 mg in the evening; ≥75 kg: 600 mg both morning and evening. Mono-infection (genotype 2 or 3): 400 mg both morning and evening. Co-infection w/ HIV (regardless of genotype): 800 mg daily. Use in combination w/ interferon alfa-2a or peginterferon alfa-2a. Treatment duration: 48 wk (genotype 1 or 4 or HIV co-infection) or 24 wk (genotype 2 or 3). Child: ≥3 yr Rebetol (Schering Plough) <47 kg: 15 mg/kg daily in 2 divided doses; 47-49 kg: 200 mg in the morning and 400 mg in the evening; 50-65 kg: 400 mg both morning and evening. Use in combination w/ interferon alfa-2b or peginterferon alfa-2b. Treatment duration: 48 wk (genotype 1) or 24 wk (genotype 2 or 3).
Special Patient Group
Patients who develop low Hb concentrations: Reduce dose.
Renal Impairment
CrCl (mL/min)
Dosage
<50
Contraindicated.
Hepatic Impairment
Severe: Contraindicated.
Administration
tab: Should be taken with food. cap: May be taken with or without food. Take consistently w/ respect to meals, either always w/ or always w/o meals.
Reconstitution
Soln for inhalation: Dissolve 6 g in a at least 75 mL water for inj. Shake well, then transfer and dilute to a total vol of 300 mL of water for inj to prepare a 20 mg/mL soln.
Contraindications
Hypersensitivity. History of severe unstable cardiac disease, haemoglobinopathies, severe, debilitating medical conditions. CrCl <50 mL/min, severe hepatic impairment or decompensated liver cirrhosis. Male partners of pregnant women. Childn and adolescents w/ history of, or existing psychiatric disorders. Pregnancy and lactation.
Special Precautions
Patient w/ history of CHF, MI and/or previous or current arrhythmic disorders, ophthalmologic disorders, thyroid disorders, low CD4 count, substance use/abuse, COPD and asthma. Renal and hepatic impairment. Childn.
Adverse Reactions
Haemolytic anaemia, leucopenia, thrombocytopenia, aplastic anaemia, DM, autoimmune disorders, GI symptoms, pancreatitis, pulmonary embolism, bacterial pneumonia, pneumothorax, CV effects, chest pain, liver dysfunction, interstitial pneumonitis, lupus erythematosus, reticulocytosis, conjunctivitis, rash. Very rarely, Stevens-Johnson syndrome and toxic epidermal necrolysis; photosensitivity, growth retardation in childn; dental/periodontal disorders. Potentially Fatal: MI, severe depression, suicidal ideation, relapse of drug abuse or overdose, bacterial infection.
This drug may cause fatigue, somnolence or confusion, if affected, do not drive or operate machinery.
Monitoring Parameters
Monitor haematologic, cardiac, resp and ophth function; growth in paed patients; pregnancy tests mthly during and for 6 mth after discontinuation.
Drug Interactions
May exacerbate immunosuppression w/ azathioprine. Increased risk of mitochondrial toxicity and lactic acidosis in HIV-positive patients taking nucleoside reverse transcriptase inhibitor (e.g. didanosine, stavudine). Increased risk of anaemia w/ zidovudine. Decreased bioavailability w/ antacids containing Mg, Al and simethicone. Increased risk of lactic acidosis w/ other nucleoside analogues.
Action
Description: Ribavirin is a synthetic nucleoside which has inhibitory action against respiratory syncytial virus, influenza virus and herpes simplex virus. The mechanism of action is not clear. It may act at several sites including cellular enzymes to interfere w/ viral nucleic acid synthesis. The mono- and triphosphate derivatives are known to be responsible for the antiviral action of the compound. Pharmacokinetics: Absorption: Rapidly absorbed from the GI tract. Bioavailability: Approx 45-64%. Time to peak plasma concentration: W/in 1-2 hr. Metabolism: Metabolised via reversible phosphorylation and degradation involving deribosylation and amide hydrolysis to form a triazole carboxyacid metabolite. Excretion: Via urine as unchanged drug and metabolite. Terminal half-life: Approx 120-170 hr.
Chemical Structure
Storage
Cap/Tab: Store at 25°C. Oral soln: Store at 25°C or between 2-8°C. Inhalation: Store between 15-30°C.