ATC Group: D06B Chemotherapeutics for topical use

Acyclovir is an antiviral agent with activity against herpes simplex virus and varicella-zoster virus. Acyclovir inhibits the DNA polymerase of the virus, preventing further proliferation.

The exact mechanism of the antiviral activity of docosanol is unknown. In vitro studies indicate that docosanol affects the fusion between the virus and the plasma membrane, which inhibits intracellular uptake and replication of virus. Docosanol has no effect against non-enveloped viruses.

Imiquimod is an immune response modifier. Saturable binding studies suggest a membrane receptor for imiquimod exists on responding immune cells. Imiquimod has no direct antiviral activity.

Picato is indicated for the cutaneous treatment of non-hyperkeratotic, non-hypertrophic actinic keratosis in adults. The mechanism of action of ingenol mebutate for use in actinic keratosis remains to be fully characterised. Results from two clinical studies on biological effects of ingenol mebutate have shown that topical administration induced epidermal necrosis and a profound inflammatory response in both epidermis and the upper dermis of the treated skin, dominated by infiltrating T cells, neutrophils and macrophages.

Lysozyme is a naturally occurring enzyme found in bodily secretions such as tears, saliva, and milk. It functions as an antimicrobial agent by cleaving the peptidoglycan component of bacterial cell walls, which leads to cell death.

Mafenide is a sulfonamide-type antimicrobial agent. The mechanism of action of mafenide is not known, but is different from that of the sulfonamides. Mafenide is not antagonized by pABA, serum, pus or tissue exudates, and there is no correlation between bacterial sensitivities to mafenide and to the sulfonamides.

Metronidazole is an anti-infectious drug belonging to the pharmacotherapeutic group of nitroimidazole derivatives, which have effect mainly on strict anaerobes. This effect is probably caused by interaction with DNS and different metabolites.

Penciclovir has demonstrated in vivo and in vitro activity against herpes simplex viruses (types 1 and 2) and varicella zoster virus. Penciclovir triphosphate persists in infected cells for more than 12 hours where it inhibits replication of viral DNA and has a half-life of 9, 10 and 20 hours in cells infected with varicella zoster virus, herpes simplex virus type 1 and herpes simplex virus type 2 respectively.

Podophyllotoxin is a metaphase inhibitor in dividing cells binding to at least one binding site on tubulin. Binding prevents tubulin polymerisation required for microtubule assembly. At higher concentrations, podophyllotoxin also inhibits nucleoside transport through the cell membrane.

Silver sulfadiazine is a sulfonamide and has broad antimicrobial activity against both Gram-positive and Gram-negative organisms including Pseudomonas aeruginosa, some yeasts and fungi. Silver sulfadiazine acts on the cell membrane and cell wall.

Tirbanibulin disrupts microtubules by direct binding to tubulin, which induces cell cycle arrest and apoptotic death of proliferating cells, and is associated with disruption of Src tyrosine kinase signalling.

Tromantadine is an antiviral medicine used to treat herpes simplex virus.