A nurse is caring for a client with a new diagnosis of herpes zoster. Which of the following medications should the nurse anticipate providing to this client?

A. Correct: Acyclovir is an antiviral medication used to treat herpes zoster (shingles) by reducing the severity and duration of symptoms. B. Incorrect: Metronidazole is an antibacterial and antiprotozoal drug, not used for viral infections. C. Incorrect: Isoniazid is used for tuberculosis, not herpes zoster. D. Incorrect: Cefepime is a cephalosporin antibiotic used for bacterial infections, not viral infections.