Makindo Medical Notes

💊 Ribavirin is a broad-spectrum antiviral that has shown survival benefit in certain viral haemorrhagic fevers (VHFs) such as Lassa fever. Its use requires specialist advice due to toxicity risks and variable evidence outside VHF. 👉 Always check the BNF link here for the latest prescribing updates.

⚙️ Mode of Action

• Broad-spectrum antiviral agent with multiple mechanisms.
• Inhibits inosine monophosphate dehydrogenase (IMPDH) → ↓ GTP synthesis → impaired viral RNA replication.
• Incorporates into viral RNA → induces lethal mutagenesis.
• Enhances host immune response against viral pathogens.

🩺 Indications

• Viral Haemorrhagic Fevers (VHFs): e.g. Lassa fever, Hantavirus, Rift Valley fever (greatest evidence in Lassa fever).
• Chronic Hepatitis C Virus (HCV): Historically used in combination with interferon (now largely replaced by DAAs, but may appear in exam contexts).

💊 Dosing (example for VHF, specialist use only)

• Initial: 2 g IV infusion.
• Then: 1 g IV QDS.
• Maintenance: 500 mg IV TDS for 6 days.
• ⚠️ Always confirm with infectious disease/virology team → dosing varies with indication, weight, and renal function.

🔗 Interactions

• ⚠️ Refer to BNF for full list.
• Notable: may ↑ toxicity with interferons; caution with didanosine (mitochondrial toxicity risk).

🚫 Contraindications

• ❌ Pregnancy (teratogenic – strict contraception required during and 6 months after therapy for both sexes).
• Severe uncontrolled cardiac disease.
• Significant haemoglobinopathies (e.g., thalassaemia major, sickle cell anaemia) due to risk of haemolysis.

⚠️ Side Effects

• 💔 Haemolytic anaemia (dose-limiting toxicity; monitor Hb).
• GI upset → nausea, diarrhoea.
• Neuropsychiatric → fatigue, irritability, insomnia, depression.
• Dermatological → rash, pruritus.
• Teratogenicity → strict contraceptive measures essential.

💡 Clinical Pearls

✔️ Most exam-relevant association = **Lassa fever** where ribavirin is life-saving if given early. ✔️ Now rarely used for Hepatitis C due to DAAs but still tested historically. ✔️ Always check pregnancy status and enforce dual contraception. ✔️ Major monitoring: **FBC, renal function, liver function**.