Vidarabine
Vidarabine, also known as adenine arabinoside or ara-A, is an antiviral drug that was one of the first antiviral agents to be developed and used in clinical practice. It is primarily used for the treatment of herpes simplex virus (HSV) infections, particularly in cases of herpes simplex encephalitis and herpes zoster in immunocompromised patients.
History[edit]
Vidarabine was first synthesized in the 1960s and was initially investigated for its potential as an anticancer agent. However, its antiviral properties were soon recognized, leading to its development as an antiviral medication. It was approved for medical use in the United States in 1976.
Mechanism of Action[edit]
Vidarabine works by inhibiting viral DNA polymerase, an enzyme critical for viral DNA replication. It is a nucleoside analog, meaning it mimics the natural nucleosides that are the building blocks of DNA. Once incorporated into viral DNA, vidarabine causes premature chain termination, effectively halting viral replication.
Pharmacokinetics[edit]
Vidarabine is administered intravenously due to its poor oral bioavailability. It is rapidly deaminated to arabinosyl hypoxanthine, which is less active. The drug is primarily excreted by the kidneys.
Clinical Uses[edit]
Vidarabine is used in the treatment of severe HSV infections, including:
- Herpes simplex encephalitis
- Neonatal herpes simplex
- Herpes zoster in immunocompromised patients
Side Effects[edit]
Common side effects of vidarabine include nausea, vomiting, diarrhea, and headache. More serious side effects can include neurotoxicity and bone marrow suppression.
