Acyclovir is an antiviral medication used to treat infections caused by herpes viruses, including genital herpes, cold sores, shingles, and chickenpox. While Acyclovir is generally well-tolerated, some patients may experience side effects. The most common acyclovir side effects include nausea, vomiting, diarrhea, headache, and dizziness. Other possible side effects may include abdominal pain, fever, hair loss, and skin rash. Rare but serious side effects may include seizures, confusion, hallucinations, and kidney problems. It is important to contact a healthcare provider immediately if any of these serious side effects occur. Patients should also inform their doctor if they are taking any other medications, as some drugs may interact with acyclovir. Overall, acyclovir is a safe and effective medication when used as directed, and any potential side effects should be discussed with a healthcare provider.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ACYCLOVIR
[2] https://www.chp.edu/our-services/transplant/liver/education/medications/acyclovir-zovirax
[3] https://www.drugs.com/sfx/acyclovir-side-effects.html