Ribavirin
Mechanism :
It is an antiviral agent and inhibits viral DNA and RNA synthesis. It is used for in the treatment of chronic hepatitis due to HCV C and RSV infections in high-risk patients.
Indication :
- Chronic Hepatitis C
- Respiratory Syncytial Virus (inhalation)
- Hemorrhagic fever with renal syndrome (HFRS) secondary to Hantavirus infection
- Lassa fever prophylaxis
- Adenovirus infection
- SSPE
Contraindications :
Hypersensitivity, Pregnancy, Male partners of pregnant women, Significant or unstable cardiac disease, Hemoglobinopathies, Autoimmune hepatitis, Hepatic impairment, Child-Pugh Class B or C, CrCl <50.
Dosing :
Oral for Hepatitis C along with combination therapy:
15 mg/kg/day in divided doses PO. Max: 800 mg/day.
Inhalation for RSV:
6 g nebulised over 12-18 hours/day for 3-7 days.
Adenovirus infection:
33 mg/kg IV loading dose, followed by 16 mg/kg IV every 6 hours for 4 days, then 8 mg/kg IV every 8 hours for 3 to 6 days (total 7 to 10 day course). Other reports use a 35 mg/kg IV loading dose then 25 mg/kg IV every 8 hours or 15 mg/kg IV every 6 hours.
SSPE:
Intrathecal ribavirin to maintain CSF concentrations between 50 to 200 mcg/ml. The initial dose is 1 mg/kg diluted with saline and injected as 1 to 2 ml via the Ommaya reservoir 1 to 3 times daily. Max: 3 mg/kg/dose.
Adverse Effect :
Hemolytic anemia, eczema, suicidal ideation, pulmonary embolism, aplastic anemia, peptic ulcer, thrombotic thrombocytopenic purpura (TTP), pancreatitis, pulmonary hypertension, pneumothorax, cyanosis, pulmonary edema, apnea, bronchospasm, red cell aplasia, bradycardia, leukopenia, thrombocytopenia, hypothyroidism, constipation, fever, fatigue, headache, asthenia, myalgia, alopecia, arthralgia.
Interaction :
Abacavir: Ribavirin may increase the hepatotoxicity of reverse transcriptase inhibitors (nucleoside) such as Abacavir. Lactic acidosis may occur. Consider modifying therapy.
Zalcitabine: Ribavirin may increase the hepatotoxicity of zalcitabine. May cause lactic acidosis. Monitor for lactic acidosis during concomitant therapy.
Zidovudine: Increased risk or severity of anemia. Consider alternate therapy or monitor more closely for anemia.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function. Avoid oral. |
| 10-20 | Dose as in normal renal function. Avoid oral. |
| <10 | Dose as in normal renal function. Avoid oral. |
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=10–20 mL/min |
Hepatic Dose :
No dose adjustment recommended. Safety and efficacy have not been established in patients with decompensated hepatic disease.