Which of the following is a contraindication for phenytoin?

Phenytoin, an antiepileptic medication, is primarily used to manage seizures. The administration routes for this medication have specific considerations. The intramuscular (IM) route is a contraindication for phenytoin due to its poor absorption and the risk of local tissue irritation. Phenytoin is known to cause infiltration and potential necrosis if administered through the IM route, which can lead to serious complications.

In contrast, the oral, intravenous (IV), and topical routes may be utilized in specific clinical contexts. The oral route is commonly used for long-term management, the IV route is appropriate for acute scenarios where rapid action is required, and topical formulations can be used for localized effects in certain situations. Thus, the IM administration of phenytoin is avoided to ensure patient safety and the effectiveness of the drug.