Final answer:
For home treatment of a systemic infection, oral medications are usually preferred for convenience, unless the drug isn't well absorbed GI tract or high plasma levels are needed quickly, in which case IV or intramuscular methods are used.
Step-by-step explanation:
The appropriate route of administration for a systemic infection that can be managed at home would be oral medications. Oral drugs are preferred for their convenience and ease of administration outside of healthcare settings. However, certain conditions or drug characteristics might necessitate the use of parenteral methods such as intravenous (IV) or intramuscular injections. This is generally the case when the drug is not readily absorbed through the gastrointestinal (GI) tract or when high plasma levels of the drug are required quickly, which can be the case with serious infections. Dosage and timing considerations are also important, with factors including drug half-life and the need to maintain therapeutic levels over a given time frame influencing the choice. For some patients, such as those with liver or kidney dysfunction, special attention to dosage is needed due to altered drug metabolism or clearance.