Products
Ribavirin is commercially available in the form of film-coated tablets (Copegus). It has been approved in many countries since 1990.
Structure and properties
Ribavirin (C8H12N4O5, Mr = 244.2 g/mol) is a purine nucleoside analog. It exists as a white crystalline powder that is readily soluble in water. In cells, the drug is biotransformed to ribavirin triphosphate.
Effects
Ribavirin (ATC J05AB04) has antiviral properties against various RNA and DNA viruses. The mechanism of action is not precisely known, and various hypotheses exist. Ribavirin has a long half-life of 140 to 160 hours and is excreted slowly as it accumulates intracellularly.
Indications
For treatment of chronic hepatitis C as part of combination therapy (peginterferon alfa, interferon-alfa, or direct antiviral wik agents). Monotherapy is not effective. Ribavirin is also used to treat some other viral diseases, but it is not officially approved for this purpose in many countries-but it is in others.
Dosage
According to the prescribing information. The tablets or capsules are taken in the morning and evening with a meal. The medicines must be handled with care because they have fruit damaging properties. Take care, for example, if tablets are broken.
Contraindications
- Hypersensitivity
- Pregnancy and lactation: caution: ribavirin is teratogenic!
- Severe heart disease
- Hemoglobinopathies
- Chronic renal failure
Full precautions can be found in the drug label.
Interactions
Ribavirin does not interact with CYP450. Drug-drug interactions have been described with antacids, nucleoside analogues, didanosine, and azathioprine.
Adverse effects
The most common potential adverse effects of combination therapy with interferons include fatigue, weakness, headache, muscle stiffness, muscle pain, nausea, psychiatric disturbances (eg, anxiety, emotional lability, irritability), and digestive disturbances. Ribavirin can cause hemolytic anemia, cardiotoxic side effects, and numerous other side effects.
