Antivirals are now available for a wide variety of viral diseases. Ribavirin, available since the mid-1980s, is used to treat respiratory syncytial virus (RSV), a cause of severe childhood respiratory infections. It is thought to inhibit messenger RNA. Ribavirin has few side effects, but is prohibitively expensive for all but the most serious cases. Amantadine and rimantadine, which are effective against strains of influenza A, act by interfering with viral uncoating.
Herpes simplex virus can now be treated by a highly selective drug, acyclovir (Zovirax), that interferes with an enzyme critical to the growth of the DNA chain. Although not a cure, the drug lessens the frequency and severity of outbreaks. Acyclovir is also used to lessen the pain and speed the healing of herpes zoster (shingles).
The search for cures and palliatives for AIDS has yielded drugs such as zidovudine (AZT), which inhibits the transcription of RNA to DNA in human immunodeficiency virus (HIV). Ganciclovir and cidofovir are used in the treatment of cytomegalovirus (CMV), a virus that affects the eyes of immunosuppressed patients. Fomivirsen, which is an antisense drug, is also used to treat CMV.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.
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