Tromantadine is an antiviral medicine used to treat herpes simplex virus. It is available in a topical gel under trade name Viru-Merz. Its performance is similar to aciclovir. Tromantadine inhibits the early and late events in the virus replication cycle. It changes the glycoproteins of the host cells, therefore impeding the absorption of the virus. It inhibits penetration of the virus. It also prevents uncoating of the virions.

Like rimantadine and amantadine, tromantadine is a derivative of adamantane.