Acyclovir is an acyclic guanosine antiviral that is available in oral and topical formulations for the treatment of herpes simplex, herpes zoster, chickenpox, and other diseases. Acyclovir is available in the form of acyclovir tablets, acyclovir cream, and acyclovir eye drops. Acyclovir tablets and acyclovir cream are mostly used to treat diseases caused by herpes virus and varicella-zoster virus infections, and acyclovir eye drops are mainly used to treat viral keratitis or to prevent damage to the conjunctiva from herpes zoster around the eyes. Acyclovir also has some therapeutic effects on hairy mucous membrane leukoplakia and flat warts, and is mostly used as adjunctive therapy. Acyclovir is metabolized by the kidneys and can cause some damage to the kidneys. Gastrointestinal reactions such as nausea and vomiting as well as neurological abnormalities such as headache and hyperventilation may also occur. Acyclovir is not recommended for people who are allergic to acyclic guanosines. Care should be taken to check kidney function and use the medication under the guidance of a doctor before using the drug, and seek medical advice in time to avoid delays in the condition if adverse reactions occur.