ribavirin

CLINICAL USE

Antiviral agent:Severe respiratory syncytial virus bronchiolitisChronic Hepatitis C in combination with Interferon α or Peginterferon α

DOSE IN NORMAL RENAL FUNCTION

Bronchiolitis: 6 g nebulised daily for 12–18 hours for 3–7 daysHepatitis C:Rebetol:<65 kg: 400 mg twice daily 65–85 kg: 400 mg in the morning and 600 mg at 6 pm >85 kg: 600 mg twice dailyCopegus: <75 kg: 400 mg in the morning and —600 mg at 6 pm>75 kg: 600 mg twice daily —

PHARMACOKINETICS

Molecular weight :244.2

%Protein binding :0

%Excreted unchanged in urine : 10–40

Volume of distribution (L/kg) :Nebulised: 647 litres; Oral: 5000 litres

half-life – normal/ESRD (hrs) :Nebulised: 9/–; Oral: 79/Increased

DOSE IN RENAL IMPAIRMENT

GFR (mL/MIN)

20 to 50 : Dose as in normal renal function. Avoid oral. See ‘Other Information’

10 to 20 : Dose as in normal renal function. Avoid oral. See ‘Other Information’

<10 : Dose as in normal renal function. Avoid oral. See ‘Other Information’

DOSE IN PATIENTS UNDERGOING RENAL REPLACEMENT THERAPIES

CAPD :Unlikely to be dialysed. Dose as in GFR <10 mL/min

HD :Not dialysed. Dose as in GFR <10 mL/min

HDF/high flux :Unknown dialysability. Dose as in GFR <10 mL/min

CAV/VVHD :Unknown dialysability. Dose as in GFR 10 to 20 mL/min

IMPORTANT DRUG INTERACTIONS

Potentially hazardous interactions with other drugs

Antivirals: ribavirin may antagonise the effects of stavudine; increased side effects with didanosine

ADMINISTRATION

Reconstition

Dissolve contents of one vial in water for injection

Route

Nebulised, oral, IV

Rate of Administration

IV: over 10–15 minutes

Comments

Nebulised: further dilute to a volume of 300 mL

OTHER INFORMATION

Oral: Administer ribavirin with interferon α 3 MIU 3 times a week or peginterferon α 1.5 mcg/kg/week

Contraindicated by the company due to reduced clearance leading to increased side effects. Ribavirin is metabolised by reversible phosphorylation and a degradative pathway involving deribosylation and amide hydrolysis to produce renally excreted active metabolites
There are two studies using ribavirin (200–400 mg a day) in combination with interferon in haemodialysis and peritoneal dialysis patients. Anaemia was one of the main problems, resulting in either increased doses of erythropoietin or discontinuation of ribavirin therapy. Most patients were stabilised on a dose of 200 mg daily or 200 mg 3 times a week.
A dose of 200 mg daily gave troughs comparable to those in patients with normal renal function taking 1200 mg daily. ( patients with —end-stage renal disease

See how to identify renal failure stages according to GFR calculation

See how to diagnose irreversible renal disease

Home