Aciclovir

Aciclovir is an antiviral medication, a nucleoside analogue that mimics guanosine, used to treat herpes simplex virus infections, chickenpox and shingles, and to prevent cytomegalovirus infection after a transplant. Viral enzymes convert it into an active form that inhibits viral DNA polymerase and is incorporated into the growing viral DNA strand, terminating the chain and decreasing viral DNA production. Chemist Howard Schaeffer and biochemist Gertrude Elion developed aciclovir at the pharmaceutical company Burroughs Wellcome, which patented it in 1974; it was approved for medical use in 1981, and Elion was awarded the 1988 Nobel Prize in Physiology or Medicine partly for its development.