Antivirals: What They Do, Medicines
Antivirals are prescription medicines that act on specific viruses, for example herpes viruses and influenza viruses. Examples include acyclovir and oseltamivir. They slow the spread of a virus in the body but do not remove it at once, and they work best when started early. They do not work against bacteria, so they are not used for infections that antibiotics treat.
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How do Antivirals work?
Antivirals block a step that a particular virus needs to copy itself or to leave an infected cell. Each antiviral works on a limited group of viruses, so a doctor chooses one that matches the infection.
Active ingredients of this type
These active ingredients belong to Antivirals. They are listed A to Z.
- Acyclovir: Acyclovir (aciclovir) is a prescription antiviral used to treat infections caused by herpes viruses.
- Oseltamivir: Oseltamivir is a prescription antiviral used to treat influenza (flu).
Common questions
Do antivirals work on all viruses?
No. Each antiviral works on a limited group of viruses. Acyclovir acts on herpes viruses and oseltamivir on influenza viruses. Colds are caused by many other viruses and have no antiviral. A doctor decides whether one is suitable.
Why do antivirals need to be started early?
Viruses multiply fastest at the start of an infection. Taking an antiviral soon after symptoms begin gives it the best chance to slow the spread. For shingles the NHS says within 3 days of the rash, and for flu within about two days.
Do antibiotics and antivirals do the same job?
No. Antibiotics act on bacteria and antivirals act on viruses. Antibiotics do not help with flu, shingles or other viral illnesses, and antivirals do not help with bacterial infections. A doctor decides which is needed.
Sources
- Aciclovir. NHS (UK)
- Influenza antiviral medications: summary for clinicians. Centers for Disease Control and Prevention (US)
- Flu. NHS (UK)
- ATC/DDD Index: J05. WHO Collaborating Centre for Drug Statistics Methodology
- National Formulary of India. Indian Pharmacopoeia Commission