Vidarabine
Synonyms :
Adenine Arabinoside, Ara-A
Mechanism :
Vidarabine, a purine nucleoside, interferes in the early stages of viral DNA synthesis. It is phosphorylated intracellularly to the triphosphate and may also be incorporated into the viral DNA. It is active against Herpes simplex virus types 1 and 2, varicella-zoster virus and vaccinia viruses.
Indication :
- It is an antiviral agent used for the treatment of acute keratoconjunctivitis and encephalitis due to herpes simplex virus.
Contraindications :
Hypersensitivity;
Concomitant admin with a corticosteroid.
Dosing :
The safety and effectiveness in pediatric patients below the age of 2 years have not been established.
Topical: 3% half inch ointment ribbon to lower conjunctival sac, 5 times a day.
(If there are no signs of improvement after 7 days, or complete re-epithelialization has not occurred by 21 days, other forms of therapy should be considered. Some severe cases may require longer treatment).
Adverse Effect :
Pancytopenia, increased bilirubin and SGPT.
Interaction :
There are no known drug interactions.
Hepatic Dose :
Should be used with caution in severe liver disease.