You're kidding. Continue the neosporin and wrapping until he can get a Rx for silvadene. (I say this as a doc who as a surgery resident ran a burn unit.)
BTW, the advantage of silvadene over neosporin is that it penetrates the burned tissue, whereas the neosporin sits on top. The neosporin can reduce the change of the burn getting infected, while the SSD can treat established infection to some degree.
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