Cold and flu prevention or treatment

Patient request for «something antiviral so I don't get sick» or for a pill to cure flu. Most acute respiratory infections are caused by rhinoviruses, adenoviruses, parainfluenza, RSV and SARS-CoV-2, with no specific etiotropic therapy. Influenza is treated with oseltamivir or zanamivir within the first 48 hours. Anti-herpetic drugs (aciclovir, valaciclovir, famciclovir) have no activity against respiratory viruses.

ICD-10 J001 drug

Also known as: Cold prevention, ARI treatment, Antiviral for flu

Marketing claims without evidence base

The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.

FFamciclovirNot recommended · Antiviral nucleoside analogue for herpes infections (HSV-1, HSV-2, VZV)Famciclovir is a nucleoside analogue active against herpesviruses (HSV-1, HSV-2, VZV). It has no activity against rhinoviruses, adenoviruses, parainfluenza, RSV, influenza viruses or SARS-CoV-2 – these viruses lack the thymidine kinase needed to activate famciclovir. The marketing position of famciclovir as a «broad-spectrum antiviral» or «immunomodulator for colds» in the labelling of some Russian generics and in pharmacy advertising is misleading. NICE, AEDV, AEMPS and FDA approved the drug only for the treatment of herpes infections. If famciclovir was prescribed for cold, flu or to «boost immunity», consider seeking a second opinion.

How to read tiers A–F

Evidence tiers belong to the drug-indication pair, not to the drug as a whole: the same substance can be A for one condition and F for another.

AStrong evidence – first or second line in international guidelines
BRecommended in selected cases
CStudy data contradict each other
DBenefit not proven, no documented harm
FDocumented harm, or risk without benefit