Final answer:
The intradermal route is inappropriate for a topical medication, which is meant for application on the skin or mucous membranes. Oral medications are preferred for systemic infections, while parenteral routes are used when oral is not feasible.
Step-by-step explanation:
In the context of routes for topical medication, the inappropriate route listed is intradermal. Topical medications are intended for application on the skin or mucous membranes to treat local conditions or deliver medications locally. Routes such as the bladder, rectum, and vagina are acceptable for certain topical medications as they involve mucous membranes. For systemic infections, convenient routes for home administration include the oral route, as most patients can easily self-administer oral medications. When oral administration is not possible or the drug is not absorbed well in the gastrointestinal tract, parenteral routes, like intravenous or intramuscular injections, are used, though typically in healthcare settings due to their complexity and the need for sterile technique.