Indications (1)

• Herpes simplex infection
• Non-genital (adult): by mouth, 200mg 5 times a day usually for 5 days
• Local treatment (adult): to the eye using ointment, 1cm 5 times a day for at least 3 days after complete healing

Safety

• Elderly - risk of neurological reactions
• Maintain adequate hydration
• Topical use: avoid cream coming in to contact with eyes and mucous membranes

Side effects

• Eye (topical): eye inflammation, eye pain
• Intravenous: nausea, photosensitivity, skin reactions, vomiting
• Oral: abdominal pain, diarrhoea, dizziness, fatigue, fever, headache, nausea, photosensitivity, skin reactions, vomiting
• Uncommon: anaemia, leucopenia thromboctyopenia

Suitability

• Pregnancy: not known to be harmful
• Breast feeding: significant amount in milk after systemic administration, not known to be harmful
• Renal impairment: risk of neurological reactions increased, maintain adequate hydration

Reference

1. BNF (2023). Aciclovir. [online] NICE. Available at: https://bnf.nice.org.uk/drugs/aciclovir/ [Accessed 3 Nov. 2026].