Nucleoside antiviral Pregnancy: Contraindicated in pregnancy — significant teratogenic and/or embryocidal potential in all species studied, at doses well below the human dose. A negative pregnancy test is required before starting; effective contraception is mandatory during treatment and for 9 months after (female patients) or 6 months after (male patients and their female partners), with routine monthly pregnancy tests. Breast-feeding must be discontinued before treatment (UK SPC §4.6).

Ribavirin

Brand names: Copegus, Rebetol

Ribavirin is a broad-spectrum antiviral guanosine analogue used for chronic hepatitis C (in combination regimens) and certain viral haemorrhagic fevers and respiratory infections.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1000 mg/day (<75 kg) or 1200 mg/day (>=75 kg)

Route: Oral

Frequency: In two divided doses (morning and evening) with food

Oral treatment of chronic hepatitis C; dose is based on body weight, viral genotype and the medicinal product used in combination. Treatment must be initiated and monitored by a physician experienced in chronic hepatitis C. With a direct-acting antiviral (DAA) or PegIFN alfa-2a: <75 kg = 1000 mg/day, >=75 kg = 1200 mg/day. PegIFN alfa-2a without DAA, genotype 2/3 treatment-naive or genotype 2/3/4 with HIV-coinfection: 800 mg/day. With PegIFN alfa-2b: <65 kg = 800 mg, 65-80 kg = 1000 mg, 81-105 kg = 1200 mg, >105 kg = 1400 mg/day. Ribavirin monotherapy must not be used. Tablets must not be broken or crushed (teratogenic potential). Duration depends on the combination product and patient/virus characteristics — refer to the combination product SmPC. Dose modification for treatment-emergent anaemia per SPC Table 2 (e.g. reduce to 600 mg/day; discontinue if haemoglobin falls below thresholds). Hepatic impairment: no dose adjustment required. Not recommended in children and adolescents under 18 years due to insufficient data.

Dose adjustments

Renal

Reduce total daily dose for creatinine clearance <=50 ml/min: CrCl 30-50 ml/min — alternating doses of 200 mg and 400 mg every other day; CrCl <30 ml/min — 200 mg daily; haemodialysis — 200 mg daily. Initiate/continue with extreme caution and intensive haemoglobin monitoring. No data in paediatric patients with renal impairment.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to ribavirin or to any of the excipients
Pregnant women (a negative pregnancy test is required immediately before initiation)
Women who are breast-feeding
History of severe pre-existing cardiac disease, including unstable or uncontrolled cardiac disease, in the previous six months
Haemoglobinopathies (e.g. thalassaemia, sickle-cell anaemia)

Side effects

Haemolytic anaemia (salient safety issue, occurring within the first weeks of therapy)
Nausea and vomiting
Asthenia, fatigue, insomnia
Cough, dyspnoea
Pruritus and rash; increased uric acid and indirect bilirubin associated with haemolysis

Clinical monograph

How it works

It interferes with viral nucleic acid synthesis through several mechanisms, including inhibition of viral RNA polymerase and induction of lethal mutagenesis of the viral genome.

Prescribing in practice

Ribavirin is teratogenic and embryocidal; effective contraception is essential during and after treatment for both female patients and female partners of male patients.
Dose-dependent haemolytic anaemia is common and may precipitate cardiac or respiratory complications.
It is contraindicated in pregnancy and requires careful pregnancy-prevention counselling before use.

Monitoring

Monitor full blood count for haemolytic anaemia and confirm a negative pregnancy test before and during treatment.

Counselling the patient

Do not become pregnant, and avoid fathering a child, during treatment and for the advised period afterwards.
Use reliable contraception throughout and report any planned or suspected pregnancy at once.
Tell your clinician about breathlessness, palpitations or unusual tiredness, which may signal anaemia.

Evidence & guidelines

Ribavirin's teratogenicity and use in combination antiviral regimens are well established and reflected in MHRA safety advice.

Reference: NICE TA75; UKHSA; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways